The 100 most-cited articles in Advanced Materials, 2022

Additive manufacturing (AM) has gained significant attention due to its ability to drive technological development as a sustainable, flexible, and customizable manufacturing scheme. Among the various AM techniques, direct ink writing (DIW) has emerged as the most versatile 3D printing technique for the broadest range of materials. DIW allows printing of practically any material, as long as the precursor ink can be engineered to demonstrate appropriate rheological behavior. This technique acts as a unique pathway to introduce design freedom, multifunctionality, and stability simultaneously into its printed structures. Here, a comprehensive review of DIW of complex 3D structures from various materials, including polymers, ceramics, glass, cement, graphene, metals, and their combinations through multimaterial printing is presented. The review begins with an overview of the fundamentals of ink rheology, followed by an in-depth discussion of the various methods to tailor the ink for DIW of different classes of materials. Then, the diverse applications of DIW ranging from electronics to…

Cardiovascular diseases remain the leading cause of death worldwide. The rapid development of flexible sensing technologies and wearable pressure sensors have attracted keen research interest and have been widely used for long-term and real-time cardiovascular status monitoring. Owing to compelling characteristics, including light weight, wearing comfort, and high sensitivity to pulse pressures, physiological pulse waveforms can be precisely and continuously monitored by flexible pressure sensors for wearable health monitoring. Herein, an overview of wearable pressure sensors for human pulse wave monitoring is presented, with a focus on the transduction mechanism, microengineering structures, and related applications in pulse wave monitoring and cardiovascular condition assessment. The conceptualizations and methods for the acquisition of physiological and pathological information related to the cardiovascular system are outlined. The biomechanics of arterial pulse waves and the working mechanism of various wearable pressure sensors, including triboelectric, piezoelectric,…

Flexible electronics is an emerging field of research involving multiple disciplines, which include but not limited to physics, chemistry, materials science, electronic engineering, and biology. However, the broad applications of flexible electronics are still restricted due to several limitations, including high Young's modulus, poor biocompatibility, and poor responsiveness. Innovative materials aiming for overcoming these drawbacks and boost its practical application is highly desirable. Hydrogel is a class of 3D crosslinked hydrated polymer networks, and its exceptional material properties render it as a promising candidate for the next generation of flexible electronics. Here, the latest methods of synthesizing advanced functional hydrogels and the state-of-art applications of hydrogel-based flexible electronics in various fields are reviewed. More importantly, the correlation between properties of the hydrogel and device performance is discussed here, to have better understanding of the development of flexible electronics by using environmentally responsive hydrogels. Last,…

Abstract M1 macrophage accumulation and excessive inflammation are commonly encountered issues in diabetic wounds and can fail in the healing process. Hence, hydrogel dressings with immunoregulatory capacity have great promise in the clinical practice of diabetic wound healing. However, current immunoregulatory hydrogels are always needed for complex interventions and high‐cost treatments, such as cytokines and cell therapies. In this study, a novel glycyrrhizic acid (GA)‐based hybrid hydrogel dressing with intrinsic immunoregulatory properties is developed to promote rapid diabetic wound healing. This hybrid hydrogel consists of interpenetrating polymer networks composed of inorganic Zn 2+ ‐induced self‐assembled GA and photo‐crosslinked methyl acrylated silk fibroin (SF), realizing both excellent injectability and mechanical strength. Notably, the SF/GA/Zn hybrid hydrogel can regulate macrophage responses in the inflammatory microenvironment, circumventing the use of any additives. The immunomodulatory properties of the hydrogel can be harnessed for safe and efficient therapeutics…

The electron-transfer process during the oxygen evolution reaction (OER) often either proceeds solely via a metal redox chemistry (adsorbate evolution mechanism (AEM), with metal bands around the Fermi level) or an oxygen redox chemistry (lattice oxygen oxidation mechanism (LOM), with oxygen bands around the Fermi level). Unlike the AEM, the LOM involves oxygen redox chemistry instead of metal redox, which leads to the formation of a direct oxygen-oxygen (OO) bond. As a result, such a process is able to bypass the rate-determining step, that is, OO bonding, in AEM, which highlights the critical advantage of LOM as compared to the conventional AEM. Thus, it has been well reported that LOM-based catalysts are able to demonstrate higher OER activities as compared to AEM-based catalysts. Here, a comprehensive understanding of the oxygen redox in LOM and all documented and possible characterization techniques that can be used to identify the oxygen redox are reviewed. This review will interpret the origins of oxygen redox in the reported LOM-based electrocatalysts and the underlying…

The variation of the vertical component distribution can significantly influence the photovoltaic performance of organic solar cells (OSCs), mainly due to its impact on exciton dissociation and charge-carrier transport and recombination. Herein, binary devices are fabricated via sequential deposition (SD) of D18 and L8-BO materials in a two-step process. Upon independently regulating the spin-coating speeds of each layer deposition, the optimal SD device shows a record power conversion efficiency (PCE) of 19.05% for binary single-junction OSCs, much higher than that of the corresponding blend casting (BC) device (18.14%). Impressively, this strategy presents excellent universality in boosting the photovoltaic performance of SD devices, exemplified by several nonfullerene acceptor systems. The mechanism studies reveal that the SD device with preferred vertical components distribution possesses high crystallinity, efficient exciton splitting, low energy loss, and balanced charge transport, resulting in all-around enhancement of photovoltaic performances. This work provides a valuable…

The ternary strategy has been widely identified as an effective approach to obtain high-efficiency organic solar cells (OSCs). However, for most ternary OSCs, the nonradiative voltage loss lies between those of the two binary devices, which limits further efficiency improvements. Herein, an asymmetric guest acceptor BTP-2F2Cl is designed and incorporated into a PM1:L8-BO host blend. Compared with the L8-BO neat film, the L8-BO:BTP-2F2Cl blend film shows higher photoluminescence quantum yield and larger exciton diffusion length. Introducing BTP-2F2Cl into the host blend extends its absorption spectrum, improves the molecular packing of host materials, and suppresses the nonradiative charge recombination of the ternary OSCs. Consequently, the power conversion efficiency is improved up to 19.17% (certified value 18.7%), which represents the highest efficiency value reported for single-junction OSCs so far. The results show that improving the exciton behaviors is a promising approach to reducing the nonradiative voltage loss and realizing high-performance OSCs.

Abstract The new‐generation flexible aqueous zinc‐ion batteries require enhanced mechanical properties and ionic conductivities at low temperature for practical applications. This fundamentally means that it is desired that the hydrogel electrolyte possesses antifreezing merits to resist flexibility loss and performance decrease at subzero temperatures. Herein, a highly flexible polysaccharide hydrogel is realized in situ and is regulated in zinc‐ion batteries through the Hofmeister effect with low‐concentration Zn(ClO 4 ) 2 salts to satisfy the abovementioned requirements. The chaotropic ClO 4 − anions, water, and polymer chains can form ternary and weak hydrogen bonding (HB), which enables the polymer chains to have improved mechanical properties, breaks the HB of water to remarkably decrease the electrolyte freezing point, and reduces the amounts of free water for effective side reactions and dendrite inhibition. Consequently, even at −30 °C, the Zn(ClO 4 ) 2 in situ optimized hydrogel electrolyte features a high ionic conductivity of 7.8 mS cm −1 and excellent flexibility, which…

Snap-through bistability is often observed in nature (e.g., fast snapping to closure of Venus flytrap) and the life (e.g., bottle caps and hair clippers). Recently, harnessing bistability and multistability in different structures and soft materials has attracted growing interest for high-performance soft actuators and soft robots. They have demonstrated broad and unique applications in high-speed locomotion on land and under water, adaptive sensing and fast grasping, shape reconfiguration, electronics-free controls with a single input, and logic computation. Here, an overview of integrating bistable and multistable structures with soft actuating materials for diverse soft actuators and soft/flexible robots is given. The mechanics-guided structural design principles for five categories of basic bistable elements from 1D to 3D (i.e., constrained beams, curved plates, dome shells, compliant mechanisms of linkages with flexible hinges and deformable origami, and balloon structures) are first presented, alongside brief discussions of typical soft actuating materials (i.e., fluidic…

Abstract Amorphous and heterojunction materials have been widely used in the field of electrocatalytic hydrogen evolution due to their unique physicochemical properties. However, the current used individual strategy still has limited effects. Hence efficient tailoring tactics with synergistic effect are highly desired. Herein, the authors have realized the deep optimization of catalytic activity by a constructing crystalline–amorphous CoSe 2 /CoP heterojunction. Benefiting from the strong electronic coupling at the interfaces, the d‐band center of the material moves further down compared to its crystalline–crystalline counterpart, optimizing the valence state and the H adsorption of Co and lowering the kinetic barrier of hydrogen evolution reaction (HER). The heterojunction shows an overpotential of 65 mV to drive a current density of 10 mA cm −2 in the acidic medium. Besides, it also shows competitive properties in both neutral and basic media. This work provides inspiration for optimizing the catalytic activity through combining a crystalline and amorphous heterojunction, which…

Highly stretchable strain sensors based on conducting polymer hydrogel are rapidly emerging as a promising candidate toward diverse wearable skins and sensing devices for soft machines. However, due to the intrinsic limitations of low stretchability and large hysteresis, existing strain sensors cannot fully exploit their potential when used in wearable or robotic systems. Here, a conducting polymer hydrogel strain sensor exhibiting both ultimate strain (300%) and negligible hysteresis (<1.5%) is presented. This is achieved through a unique microphase semiseparated network design by compositing poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanofibers with poly(vinyl alcohol) (PVA) and facile fabrication by combining 3D printing and successive freeze-thawing. The overall superior performances of the strain sensor including stretchability, linearity, cyclic stability, and robustness against mechanical twisting and pressing are systematically characterized. The integration and application of such strain sensor with electronic skins are further demonstrated to…

Abstract Electrocatalytic oxidation of 5‐hydroxymethylfurfural (HMF) provides an efficient way to obtain high‐value‐added biomass‐derived chemicals. Compared with other transition metal oxides, CuO exhibits poor oxygen evolution reaction performance, leading to high Faraday efficiency for HMF oxidation. However, the weak adsorption and activation ability of CuO to OH − species restricts its further development. Herein, the CuO–PdO heterogeneous interface is successfully constructed, resulting in an advanced onset‐potential of the HMF oxidation reaction (HMFOR), a higher current density than CuO. The results of open‐circuit potential, in situ infrared spectroscopy, and theoretical calculations indicate that the introduction of PdO enhances the adsorption capacity of the organic molecule. Meanwhile, the CuO–PdO heterogeneous interface promotes the adsorption and activation of OH − species, as demonstrated by zeta potential and electrochemical measurements. This work elucidates the adsorption enhancement mechanism of heterogeneous interfaces and provides constructive guidance for…

Abstract Improving charge extraction and suppressing charge recombination are critically important to minimize the loss of absorbed photons and improve the device performance of polymer solar cells (PSCs). In this work, highly efficient PSCs are demonstrated by progressively improving the charge extraction and suppressing the charge recombination through the combination of side‐chain engineering of new nonfullerene acceptors (NFAs), adopting ternary blends, and introducing volatilizable solid additives. The 2D side chains on BTP‐Th induce a certain steric hindrance for molecular packing and phase separation, which is mitigated by fluorination of side chains on BTP‐FTh. Moreover, by introducing two highly crystalline molecules as the second acceptor and volatilizable solid additive, respectively, into the BTP‐FTh‐based host blend, the molecular crystallinity is significantly improved and the blend morphology is finely optimized. As expected, enhanced charge extraction and suppressed charge recombination are progressively realized, contributing to the largely improved fill factor (FF)…

Abstract Composite polymer electrolytes (CPEs) utilizing fillers as the promoting component bridge the gap between solid polymer electrolytes and inorganic solid electrolytes. The integration of fillers into the polymer matrices is demonstrated as a prevailing strategy to enhance Li‐ion transport and assist in constructing Li + ‐conducting electrode–electrolyte interface layer, which addresses the two key barriers of solid‐state lithium batteries (SSLBs): low ionic conductivity of electrolyte and high interfacial impedance. Recent review articles have largely focused on the performance of a broad spectrum of CPEs and the general effects of fillers on SSLBs device. Recognizing this, in this review, after briefly presenting the categories of fillers (traditional and emerged) and the promoted ionic conducting mechanisms in CPEs, the progress in the interfacial structure design principle, with the emphasis on the crucial influence of filler size, concentration, and hybridization strategies on filler–polymer interface that is the most critical to Li‐ion transport is assessed. The latest…

Abstract The development of bifunctional water‐splitting electrocatalysts that are efficient and stable over a wide range of pH is of great significance but challenging. Here, an atomically dispersed Ru/Co dual‐sites catalyst is reported anchored on N‐doped carbon (Ru/Co–N–C) for outstanding oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in both acidic and alkaline electrolytes. The Ru/Co–N–C catalyst requires the overpotential of only 13 and 23 mV for HER, 232 and 247 mV for OER to deliver a current density of 10 mA cm geo −2 in 0.5 m H 2 SO 4 and 1 m KOH, respectively, outperforming benchmark catalysts Pt/C and RuO 2 . Theoretical calculations reveal that the introduction of Co–N4 sites into Ru/Co–N–C efficiently modify the electronic structure of Ru by enlarging Ru–O covalency and increasing Ru electron density, which in turn optimize the bonding strength between oxygen/hydrogen intermediate species with Ru sites, thereby enhancing OER and HER performance. Furthermore, the incorporation of Co–N4 sites induces electron redistribution around Ru–N4, thus…

Abstract Efficient electrode materials, that combine high power and high energy, are the crucial requisites of sodium‐ion batteries (SIBs), which have unwrapped new possibilities in the areas of grid‐scale energy storage. Hard carbons (HCs) are considered as the leading candidate anode materials for SIBs, however, the primary challenge of slow charge‐transfer kinetics at the low potential region (<0.1 V) remains unresolved till date, and the underlying structure–performance correlation is under debate. Herein, ultrafast sodium storage in the whole‐voltage‐region (0.01–2 V), with the Na + diffusion coefficient enhanced by 2 orders of magnitude (≈10 –7 cm 2 s –1 ) through rationally deploying the physical parameters of HCs using a ZnO‐assisted bulk etching strategy is reported. It is unveiled that the Na + adsorption energy ( E a ) and diffusion barrier ( E b ) are in a positive and negative linear relationship with the carbon p‐band center, respectively, and balance of E a and E b is critical in enhancing the charge‐storage kinetics. The charge‐storage mechanism in HCs is evidenced…

Abstract Perovskite solar cells (PSCs) based on the regular n–i–p device architecture have reached above 25% certified efficiency with continuously reported improvements in recent years. A key common factor for these recent breakthroughs is the development of SnO 2 as an effective electron transport layer in these devices. In this article, the key advances in SnO 2 development are reviewed, including various deposition approaches and surface treatment strategies, to enhance the bulk and interface properties of SnO 2 for highly efficient and stable n–i–p PSCs. In addition, the general materials chemistry associated with SnO 2 along with the corresponding materials challenges and improvement strategies are discussed, focusing on defects, intrinsic properties, and impact on device characteristics. Finally, some SnO 2 implementations related to scalable processes and flexible devices are highlighted, and perspectives on the future development of efficient and stable large‐scale perovskite solar modules are also provided.

Abstract Fe–N–C catalysts offer excellent performance for the oxygen reduction reaction (ORR) in alkaline media. With a view toward boosting the intrinsic ORR activity of Fe single‐atom sites in Fe–N–C catalysts, fine‐tuning the local coordination of the Fe sites to optimize the binding energies of ORR intermediates is imperative. Herein, a porous FeN4–O–NCR electrocatalyst rich in catalytically accessible FeN4–O sites (wherein the Fe single atoms are coordinated to four in‐plane nitrogen atoms and one subsurface axial oxygen atom) supported on N‐doped carbon nanorods (NCR) is reported. Fe K‐edge X‐ray absorption spectroscopy (XAS) verifies the presence of FeN4–O active sites in FeN4–O–NCR, while density functional theory calculations reveal that the FeN4–O coordination offers a lower energy and more selective 4‐electron/4‐proton ORR pathway compared to traditional FeN4 sites. Electrochemical tests validate the outstanding intrinsic activity of FeN4–O–NCR for alkaline ORR, outperforming Pt/C and almost all other M–N–C catalysts reported to date. A primary zinc–air battery…

Aqueous rechargeable zinc-iodine batteries (ZIBs), including zinc-iodine redox flow batteries and static ZIBs, are promising candidates for future grid-scale electrochemical energy storage. They are safe with great theoretical capacity, high energy, and power density. Nevertheless, to make aqueous rechargeable ZIBs practically feasible, there are quite a few hurdles that need to be overcome, including self-discharge, sluggish kinetics, low energy density, and instability of Zn metal anodes. This article first reviews the electrochemistry in aqueous rechargeable ZIBs, including the flow and static battery configurations and their electrode reactions. Then the authors discuss the fundamental questions of ZIBs and highlight the key strategies and recent accomplishments in tackling the challenges. Last, they share their thoughts on the future research development in aqueous rechargeable ZIBs.

Although lithium-sulfur (Li-S) batteries are promising next-generation energy-storage systems, their practical applications are limited by the growth of Li dendrites and lithium polysulfide shuttling. These problems can be mitigated through the use of single-atom catalysts (SACs), which exhibit the advantages of maximal atom utilization efficiency (≈100%) and unique catalytic properties, thus effectively enhancing the performance of electrode materials in energy-storage devices. This review systematically summarizes the recent progress in SACs intended for use in Li-metal anodes, S cathodes, and separators, briefly introducing the operating principles of Li-S batteries, the action mechanisms of the corresponding SACs, and the fundamentals of SACs activity, and then comprehensively describes the main strategies for SACs synthesis. Subsequently, the applications of SACs and the principles of SACs operation in reinforced Li-S batteries as well as other metal-S batteries are individually illustrated, and the major challenges of SACs usage in Li-S batteries as well as future development…

Abstract A record power conversion efficiency (PCE) of over 19% is realized in planar‐mixed heterojunction (PMHJ) organic solar cells (OSCs) by adopting the asymmetric selenium substitution strategy in making a pseudosymmetric electron acceptor, BS3TSe‐4F. The combined molecular asymmetry with more polarizable selenium substitution increases the dielectric constant of the D18/BS3TSe‐4F blend, helping lower the exciton binding energy. On the other hand, dimer packing in BS3TSe‐4F is facilitated to enable free charge generation, helping more efficient exciton dissociation and lowering the radiative recombination loss (ΔE2) of OSCs. As a result, PMHJ OSCs based on D18/BS3TSe‐4F achieve a PCE of 18.48%. By incorporating another mid‐bandgap acceptor Y6‐O into D18/BS3TSe‐4F to form a ternary PMHJ, a higher open‐circuit voltage (VOC) can be achieved to realize an impressive PCE of 19.03%. The findings of using pseudosymmetric electron acceptors in enhancing device efficiency provides an effective way to develop highly efficient acceptor materials for OSCs.

Abstract NiOOH is considered as the most active intermediate during electrochemical oxidation reaction, however, it is hard to directly synthesize due to high oxidation energy. Herein, theoretical calculations predict that α‐FeOOH enables a decline in formation energy and an improvement in stabilization of NiOOH in NiFe‐based layered double hydroxide (LDH). Inspiringly, a composite composed of α‐FeOOH and LDH is well‐designed and successfully fabricated in hydrothermal treatment by adding extra Fe 3+ resource, and stable NiOOH is obtained by the following electro‐oxidation method. Benefiting from strong electron‐capturing capability of α‐FeOOH, it efficiently promotes charge redistribution around the Ni/Fe sites and activates Ni atoms of LDH, verified by X‐ray photoelectron spectra (XPS) and X‐ray absorption spectra (XAS). The d‐band center is optimized that balances the absorption and desorption energy, and thus Gibbs free energy barrier is lowered dramatically toward oxygen evolution reaction (OER) and urea oxidation reaction (UOR), and finally showing an outstanding overpotential…

Abstract Aqueous Zn–iodine (Zn–I 2 ) batteries have been regarded as a promising energy‐storage system owing to their high energy/power density, safety, and cost‐effectiveness. However, the polyiodide shuttling results in serious active mass loss and Zn corrosion, which limits the cycling life of Zn–I 2 batteries. Inspired by the chromogenic reaction between starch and iodine, a structure confinement strategy is proposed to suppress polyiodide shuttling in Zn–I 2 batteries by hiring starch, due to its unique double‐helix structure. In situ Raman spectroscopy demonstrates an I 5 − ‐dominated I − /I 2 conversion mechanism when using starch. The I 5 − presents a much stronger bonding with starch than I 3 − , inhibiting the polyiodide shuttling in Zn–I 2 batteries, which is confirmed by in situ ultraviolet–visible spectra. Consequently, a highly reversible Zn–I 2 battery with high Coulombic efficiency (≈100% at 0.2 A g −1 ) and ultralong cycling stability (>50 000 cycles) is realized. Simultaneously, the Zn corrosion triggered by polyiodide is effectively inhibited owing to the…

2D materials show many particular properties, such as high surface-to-volume ratio, high anisotropic degree, and adjustable chemical functionality. These unique properties in 2D materials have sparked immense interest due to their applications in photocatalytic systems, resulting in significantly enhanced light capture, charge-transfer kinetics, and surface reaction. Herein, the research progress in 2D photocatalysts based on varied compositions and functions, followed by specific surface modification strategies, is introduced. Fundamental principles focusing on light harvesting, charge separation, and molecular adsorption/activation in the 2D-material-based photocatalytic system are systemically explored. The examples described here detail the use of 2D materials in various photocatalytic energy-conversion systems, including water splitting, carbon dioxide reduction, nitrogen fixation, hydrogen peroxide production, and organic synthesis. Finally, by elaborating the challenges and possible solutions for developing these 2D materials, the review is expected to provide some…

Molecular imprinting technology (MIT) produces artificial binding sites with precise complementarity to substrates and thereby is capable of exquisite molecular recognition. Over five decades of evolution, it is predicted that the resulting host imprinted materials will overtake natural receptors for research and application purposes, but in practice, this has not yet been realized due to the unsustainability of their life cycles (i.e., precursors, creation, use, recycling, and end-of-life). To address this issue, greenificated molecularly imprinted polymers (GMIPs) are a new class of plastic antibodies that have approached sustainability by following one or more of the greenification principles, while also demonstrating more far-reaching applications compared to their natural counterparts. In this review, the most recent developments in the delicate design and advanced application of GMIPs in six fast-growing and emerging fields are surveyed, namely biomedicine/therapy, catalysis, energy harvesting/storage, nanoparticle detection, gas sensing/adsorption, and environmental…

Abstract Conducting polymer hydrogels are promising materials in soft bioelectronics because of their tissue‐like mechanical properties and the capability of electrical interaction with tissues. However, it is challenging to balance electrical conductivity and mechanical stretchability: pure conducting polymer hydrogels are highly conductive, but they are brittle; while incorporating the conducting network with a soft network to form a double network can improve the stretchability, its electrical conductivity significantly decreases. Here, the problem is addressed by concentrating a poorly crosslinked precursor hydrogel with a high content ratio of the conducting polymer to achieve a densified double‐network hydrogel (5.5 wt% conducting polymer), exhibiting both high electrical conductivity (≈10 S cm –1 ) and a large fracture strain (≈150%), in addition to high biocompatibility, tissue‐like softness, low swelling ratio, and desired electrochemical properties for bioelectronics. A surface grafting method is further used to form an adhesive layer on the conducting hydrogel, enabling…

Abstract Traditional electronic skin (e‐skin), due to the lack of human‐brain‐like thinking and judging capability, is powerless to accelerate the pace to the intelligent era. Herein, artificial intelligence (AI)‐motivated full‐skin bionic (FSB) e‐skin consisting of the structures of human vellus hair, epidermis–dermis–hypodermis, is proposed. Benefiting from the double interlocked layered microcone structure and supercapacitive iontronic effect, the FSB e‐skin exhibits ultrahigh sensitivity of 8053.1 kPa −1 (<1 kPa), linear sensitivity of 3103.5 kPa −1 (1–34 kPa), and fast response/recovery time of <5.6 ms. In addition, it can realize the evolution from tactile perception to advanced intelligent tactile cognition after being equipped with a “brain”. First, static/dynamic contactless tactile perception is achieved based on the triboelectric effect of the vellus hair bionics. Second, the supercapacitive iontronic effect based structural bionics of the epidermis–dermis–hypodermis and a five‐layer multilayer perception (MLP) enable the general intelligent tactile cognition of gesture…

Abstract Two‐electron oxygen photoreduction to hydrogen peroxide (H 2 O 2 ) is seriously inhibited by its sluggish charge kinetics. Herein, a polarization engineering strategy is demonstrated by grafting (thio)urea functional groups onto covalent triazine frameworks (CTFs), giving rise to significantly promoted charge separation/transport and obviously enhanced proton transfer. The thiourea‐functionalized CTF (Bpt‐CTF) presents a substantial improvement in the photocatalytic H 2 O 2 production rate to 3268.1 µmol h −1 g −1 with no sacrificial agents or cocatalysts that is over an order of magnitude higher than unfunctionalized CTF (Dc‐CTF), and a remarkable quantum efficiency of 8.6% at 400 nm. Mechanistic studies reveal the photocatalytic performance is attributed to the prominently enhanced two‐electron oxygen reduction reaction by forming endoperoxide at the triazine unit and highly concentrated holes at the thiourea site. The generated O 2 from water oxidation is subsequently consumed by the oxygen reduction reaction (ORR), thereby boosting overall reaction kinetics. The…

Abstract The practical application of the Zn‐metal anode for aqueous batteries is greatly restricted by catastrophic dendrite growth, intricate hydrogen evolution, and parasitic surface passivation. Herein, a polyanionic hydrogel film is introduced as a protective layer on the Zn anode with the assistance of a silane coupling agent (denoted as Zn–SHn). The hydrogel framework with zincophilic –SO 3 − functional groups uniformizes the zinc ions flux and transport. Furthermore, such a hydrogel layer chemically bonded on the Zn surface possesses an anti‐catalysis effect, which effectively suppresses both the hydrogen evolution reaction and formation of Zn dendrites. As a result, stable and reversible Zn stripping/plating at various currents and capacities is achieved. A full cell by pairing the Zn–SHn anode with a NaV 3 O 8 ·1.5 H 2 O cathode shows a capacity of around 176 mAh g −1 with a retention around 67% over 4000 cycles at 10 A g −1 . This polyanionic hydrogel film protection strategy paves a new way for future Zn‐anode design and safe aqueous batteries construction.

Abstract Designing heterojunction photocatalysts imitating natural photosynthetic systems has been a promising approach for photocatalytic hydrogen generation. However, in the traditional Z‐Scheme artificial photosynthetic systems, the poor charge separation, and rapid recombination of photogenerated carriers remain a huge bottleneck. To rationally design S‐Scheme (i.e., Step scheme) heterojunctions by avoiding the futile charge transport routes is therefore seen as an attractive approach to achieving high hydrogen evolution rates. Herein, a twin S‐scheme heterojunction is proposed involving graphitic C 3 N 4 nanosheets self‐assembled with hydrogen‐doped rutile TiO 2 nanorods and anatase TiO 2 nanoparticles. This catalyst shows an excellent photocatalytic hydrogen evolution rate of 62.37 mmol g −1 h −1 and high apparent quantum efficiency of 45.9% at 365 nm. The significant enhancement of photocatalytic performance is attributed to the efficient charge separation and transfer induced by the unique twin S‐scheme structure. The charge transfer route in the twin S‐scheme is confirmed…

Abstract Artificial photosynthetic solar‐to‐chemical cycles enable an entire environment to operate in a more complex, yet effective, way to perform natural photosynthesis. However, such artificial systems suffer from a lack of well‐established photocatalysts with the ability to harvest the solar spectrum and rich catalytic active‐site density. Benefiting from extensive experimental and theoretical investigations, this bottleneck may be overcome by devising a photocatalytic platform based on metal sulfides with predominant electronic, physical, and chemical properties. These tunable properties can endow them with abundant active sites, favorable light utilization, and expedited charge transportation for solar‐to‐chemical conversion. Here, it is described how some vital lessons extracted from previous investigations are employed to promote the further development of metal sulfides for artificial photosynthesis, including water splitting, CO 2 reduction, N 2 reduction, and pollutant removal. Their functions, properties, synthetic strategies, emerging issues, design principles, and…

Abstract Cuproptosis, a newly identified form of regulated cell death that is copper‐dependent, offers great opportunities for exploring the use of copper‐based nanomaterials inducing cuproptosis for cancer treatment. Here, a glucose oxidase (GOx)‐engineered nonporous copper(I) 1,2,4‐triazolate ([Cu(tz)]) coordination polymer (CP) nanoplatform, denoted as GOx@[Cu(tz)], for starvation‐augmented cuproptosis and photodynamic synergistic therapy is developed. Importantly, the catalytic activity of GOx is shielded in the nonporous scaffold but can be “turned on” for efficient glucose depletion only upon glutathione (GSH) stimulation in cancer cells, thereby proceeding cancer starvation therapy. The depletion of glucose and GSH sensitizes cancer cells to the GOx@[Cu(tz)]‐mediated cuproptosis, producing aggregation of lipoylated mitochondrial proteins, the target of copper‐induced toxicity. The increased intracellular hydrogen peroxide (H2O2) levels, due to the oxidation of glucose, activates the type I photodynamic therapy (PDT) efficacy of GOx@[Cu(tz)]. The in vivo experimental results…

Lithium-metal batteries (LMBs) are representative of post-lithium-ion batteries with the great promise of increasing the energy density drastically by utilizing the low operating voltage and high specific capacity of metallic lithium. LMBs currently stand at a point of transition at which the accumulation of knowledge from fundamental research is being translated into large-scale commercialization. This review summarizes the available strategies for addressing the intrinsic shortcomings of LMBs, such as the suppression of dendritic growth and parasitic reactions from the material to the electrode to the cell level. The discussion pertaining to the cell level includes efforts and concerns relating to scaling up established knowledge and expertise with the view of commercialization. This review intends to encourage researchers in both fundamental research institutions and industry to make a synergistic effort and share their views comprehensively to ensure that LMB technology continues to evolve in harmony to become a mature technology.

Recognizing and controlling the structure-activity relationships of single-atom catalysts (SACs) is vital for manipulating their catalytic properties for various practical applications. Herein, Fe SACs supported on nitrogen-doped carbon (SA-Fe/CN) are reported, which show high catalytic reactivity (97% degradation of bisphenol A in only 5 min), high stability (80% of reactivity maintained after five runs), and wide pH suitability (working pH range 3-11) toward Fenton-like reactions. The roles of different N species in these reactions are further explored, both experimentally and theoretically. It is discovered that graphitic N is an adsorptive site for the target molecule, pyrrolic N coordinates with Fe(III) and plays a dominant role in the reaction, and pyridinic N, coordinated with Fe(II), is only a minor contributor to the reactivity of SA-Fe/CN. Density functional theory (DFT) calculations reveal that a lower d-band center location of pyrrolic-type Fe sites leads to the easy generation of Fe-oxo intermediates, and thus, excellent catalytic properties.

Abstract Cooperative coupling of photocatalytic H 2 O 2 production with organic synthesis has an expansive perspective in converting solar energy into storable chemical energy. However, traditional powder photocatalysts suffer from severe agglomeration, limited light absorption, poor gas reactant accessibility, and reusable difficulty, which greatly hinders their large‐scale application. Herein, floatable composite photocatalysts are synthesized by immobilizing hydrophobic TiO 2 and Bi 2 O 3 on lightweight polystyrene (PS) spheres via hydrothermal and photodeposition methods. The floatable photocatalysts are not only solar transparent, but also upgrade the contact between reactants and photocatalysts. Thus, the floatable step‐scheme (S‐scheme) TiO 2 /Bi 2 O 3 photocatalyst exhibits a drastically enhanced H 2 O 2 yield of 1.15 m m h −1 and decent furfuryl alcohol conversion to furoic acid synchronously. Furthermore, the S‐scheme mechanism and dynamics are systematically investigated by in situ irradiated X‐ray photoelectron spectroscopy and femtosecond transient absorption spectrum…

The sensing performances of gas sensors must be improved and diversified to enhance quality of life by ensuring health, safety, and convenience. Metal-organic frameworks (MOFs), which exhibit an extremely high surface area, abundant porosity, and unique surface chemistry, provide a promising framework for facilitating gas-sensor innovations. Enhanced understanding of conduction mechanisms of MOFs has facilitated their use as gas-sensing materials, and various types of MOFs have been developed by examining the compositional and morphological dependences and implementing catalyst incorporation and light activation. Owing to their inherent separation and absorption properties and catalytic activity, MOFs are applied as molecular sieves, absorptive filtering layers, and heterogeneous catalysts. In addition, oxide- or carbon-based sensing materials with complex structures or catalytic composites can be derived by the appropriate post-treatment of MOFs. This review discusses the effective techniques to design optimal MOFs, in terms of computational screening and synthesis methods.…

Abstract Selective photoreduction of carbon dioxide (CO2) into carbon‐neutral fuels such as methane (CH4) is extremely desirable but remains a challenge since sluggish multiple proton–electron coupling transfer and various C1 intermediates are involved. Herein, a synergistic function between single Pd atoms (Pd1) and Pd nanoparticles (PdNPs) on graphitic carbon nitride (C3N4) for photocatalytic CO2 methanation is presented. The catalyst achieves a high selectivity of 97.8% for CH4 production with a yield of 20.3 µmol gcat.−1 h−1 in pure water. Mechanistic studies revealed that Pd1 sites activated CO2, while PdNPs sites boosted water (H2O) dissociation for increased H* coverage. The H* produced by PdNPs migrate to the Pd1 sites to promote multiple proton–electron coupling transfer via hydrogen spillover. Moreover, the adjacent Pd1 and PdNPs effectively stabilized intermediates such as *CHO, thereby favoring the pathway for CH4 production. This work provides a new perspective into the development of selective photocatalytic CO2 conversion through the artful design of synergistic…

Abstract Flexible perovskite solar cells (f‐PSCs) have attracted great attention because of their unique advantages in lightweight and portable electronics applications. However, their efficiencies are far inferior to those of their rigid counterparts. Herein, a novel histamine diiodate (HADI) is designed based on theoretical study to modify the SnO 2 /perovskite interface. Systematic experimental results reveal that the HADI serves effectively as a multifunctional agent mainly in three aspects: 1) surface modification to realign the SnO 2 conduction band upward to improve interfacial charge extraction; 2) passivating the buried perovskite surface, and 3) bridging between the SnO 2 and perovskite layers for effective charge transfer. Consequently, the rigid MA‐free PSCs based on the HADI‐SnO 2 electron transport layer (ETL) display not only a high champion power conversion efficiency (PCE) of 24.79% and open‐circuit voltage ( V OC ) of 1.20 V but also outstanding stability as demonstrated by the PSCs preserving 91% of their initial efficiencies after being exposed to ambient…

Abstract It has long been a global imperative to develop high‐energy‐density lithium‐ion batteries (LIBs) to meet the ever‐growing electric vehicle market. One of the most effective strategies for boosting the energy density of LIBs is to increase the output voltage, which largely depends upon the cathode materials. As the most‐promising cathodes for high‐voltage LIBs (>4 V vs Li/Li + ), four major categories of cathodes including lithium‐rich layered oxides, nickel‐rich layered oxides, spinel oxides, and high‐voltage polyanionic compounds still encounter severe challenges to realize the improvement of output voltage while maintaining high capacity, fast rate capability, and long service life. This review focuses on the key links in the development of high‐voltage cathode materials from the lab to industrialization. First, the failure mechanisms of the four kinds of materials are clarified, and the optimization strategies, particularly solutions that are easy for large‐scale production, are considered. Then, to bridge the gap between lab and industry, the cost management, safety…

Abstract Impossible voltage plateau regulation for the cathode materials with fixed active elemental center is a pressing issue hindering the development of Na‐superionic‐conductor (NASICON)‐type Na 3 V 2 (PO 4 ) 2 F 3 (NVPF) cathodes in sodium‐ion batteries (SIBs). Herein, a high‐entropy substitution strategy, to alter the detailed crystal structure of NVPF without changing the central active V atom, is pioneeringly utilized, achieving simultaneous electronic conductivity enhancement and diffusion barrier reduction for Na + , according to theoretical calculations. The as‐prepared carbon‐free high‐entropy Na 3 V 1.9 (Ca,Mg,Al,Cr,Mn) 0.1 (PO 4 ) 2 F 3 (HE‐NVPF) cathode can deliver higher mean voltage of 3.81 V and more advantageous energy density up to 445.5 Wh kg −1 , which is attributed by the diverse transition‐metal elemental substitution in high‐entropy crystalline. More importantly, high‐entropy introduction can help realize disordered rearrangement of Na + at Na(2) active sites, thereby to refrain from unfavorable discharging behaviors at low‐voltage region, further lifting up…

Abstract Graphite, commonly including artificial graphite and natural graphite (NG), possesses a relatively high theoretical capacity of 372 mA h g –1 and appropriate lithiation/de‐lithiation potential, and has been extensively used as the anode of lithium‐ion batteries (LIBs). With the requirements of reducing CO 2 emission to achieve carbon neutral, the market share of NG anode will continue to grow due to its excellent processability and low production energy consumption. NG, which is abundant in China, can be divided into flake graphite (FG) and microcrystalline graphite (MG). In the past 30 years, many researchers have focused on developing modified NG and its derivatives with superior electrochemical performance, promoting their wide applications in LIBs. Here, a comprehensive overview of the origin, roles, and research progress of NG‐based materials in ongoing LIBs is provided, including their structure, properties, electrochemical performance, modification methods, derivatives, composites, and applications, especially the strategies to improve their high‐rate and…

Abstract Achieving efficient and durable nonprecious hydrogen evolution reaction (HER) catalysts for scaling up alkaline water/seawater electrolysis is desirable but remains a significant challenge. Here, a heterogeneous Ni‐MoN catalyst consisting of Ni and MoN nanoparticles on amorphous MoN nanorods that can sustain large‐current‐density HER with outstanding performance is demonstrated. The hierarchical nanorod–nanoparticle structure, along with a large surface area and multidimensional boundaries/defects endows the catalyst with abundant active sites. The hydrophilic surface helps to achieve accelerated gas‐release capabilities and is effective in preventing catalyst degradation during water electrolysis. Theoretical calculations further prove that the combination of Ni and MoN effectively modulates the electron redistribution at their interface and promotes the sluggish water‐dissociation kinetics at the Mo sites. Consequently, this Ni‐MoN catalyst requires low overpotentials of 61 and 136 mV to drive current densities of 100 and 1000 mA cm −2 , respectively, in 1 m KOH and…

Hexagonal boron nitride (h-BN) is a layered inorganic synthetic crystal exhibiting high temperature stability and high thermal conductivity. As a ceramic material it has been widely used for thermal management, heat shielding, lubrication, and as a filler material for structural composites. Recent scientific advances in isolating atomically thin monolayers from layered van der Waals crystals to study their unique properties has propelled research interest in mono/few layered h-BN as a wide bandgap insulating support for nanoscale electronics, tunnel barriers, communications, neutron detectors, optics, sensing, novel separations, quantum emission from defects, among others. Realizing these futuristic applications hinges on scalable cost-effective high-quality h-BN synthesis. Here, the authors review scalable approaches of high-quality mono/multilayer h-BN synthesis, discuss the challenges and opportunities for each method, and contextualize their relevance to emerging applications. Maintaining a stoichiometric balance B:N = 1 as the atoms incorporate into the growing layered crystal…

Abstract Multifunctional interfacial engineering on the Zn anode to conquer dendrite growth, hydrogen evolution, and the sluggish kinetics associated with Zn deposition is highly desirable for boosting the commercialization of aqueous zinc‐ion batteries. Herein, a spontaneous construction of carbonyl‐containing layer on a Zn anode (Zn@ZCO) is rationally designed as an ion redistributor and functional protective interphase. It has strong zincphilicity and dendrite suppression ability due to the significant interaction of the highly electronegative and highly nucleophilic carbonyl oxygen, favoring ion transport and homogenizing Zn deposition effectively. On the other side, the hydrogen bond formed by the proton acceptor of oxygen atom in ZCO regulates the Zn‐ion desolvation process at the interfaces, thus bounding water activity and then mitigating water‐induced parasitic reactions. Consequently, the Zn@ZCO anode exhibits an extended cycling lifespan of 5000 h (>208 days) with a dendrite‐free surface and negligible by‐products. More encouragingly, the effectiveness is also convincing…

Abstract Limited by single metal active sites and low electrical conductivity, designing nickel‐based metal–organic framework (MOF) materials with high capacity and high energy density remains a challenge. Herein, a series of bi/multimetallic MOF‐74 family materials in situ grown on carbon cloth (CC) by doping Mx+ ions in Ni‐MOF‐74 is fabricated: NiM‐MOF@CC (M = Mn2+, Co2+, Cu2+, Zn2+, Al3+, Fe3+), and NiCoM‐MOF@CC (M = Mn2+, Zn2+, Al3+, Fe3+). The type and ratio of doping metal ions can be adjusted while the original topology is preserved. Different metal ions are confirmed by X‐ray absorption fine structure (XAFS). Furthermore, these Ni‐based MOF electrodes are directly utilized as cathodes for aqueous nickel–zinc batteries (NZBs). Among all the as‐prepared electrodes, NiCo‐MOF@CC‐3 (NCM@CC‐3), with an optimized Co/Ni ratio of 1:1, exhibits the best electrical conductivity, which is according to the density functional theory (DFT) theoretical calculations. The NCM@CC‐3//Zn@CC battery achieves a high specific capacity of 1.77 mAh cm–2, a high areal energy density of 2.97 mWh cm–2,…

Ambient-pressure-dried (APD) preparation of transition metal carbide/nitrides (MXene) aerogels is highly desirable yet remains highly challenging. Here, ultrathin, high-strength-to-weight-ratio, renewable cellulose nanofibers (CNFs) are efficiently utilized to assist in the APD preparation of ultralight yet robust, highly conductive, large-area MXene-based aerogels via a facile, energy-efficient, eco-friendly, and scalable freezing-exchanging-drying approach. The strong interactions of large-aspect-ratio CNF and MXene as well as the biomimetic nacre-like microstructure induce high mechanical strength and stability to avoid the structure collapse of aerogels in the APD process. Abundant functional groups of CNFs facilitate the chemical crosslinking of MXene-based aerogels, significantly improving the hydrophobicity, water resistance, and even oxidation stability. The ultrathin, 1D nature of the CNF renders the minimal MXenes' interlayered gaps and numerous heterogeneous interfaces, yielding the excellent conductivity and electromagnetic interference (EMI) shielding performance of…

Abstract Single‐atom nanozymes (SAzymes) represent a new research frontier in the biomedical fields. The rational design and controllable synthesis of SAzymes with well‐defined electronic and geometric structures are essential for maximizing their enzyme‐like catalytic activity and therapeutic efficacy but remain challenging. Here, a melamine‐mediated pyrolysis activation strategy is reported for the controllable fabrication of iron‐based SAzyme containing five‐coordinated structure (FeN 5 ), identified by transmission electron microscopy imaging and X‐ray absorption fine structure analyses. The FeN 5 SAzyme exhibits superior peroxidase‐like activity owing to the optimized coordination structure, and the corresponding catalytic efficiency of Fe‐species in the FeN 5 SAzyme is 7.64 and 3.45 × 10 5 times higher than those in traditional FeN 4 SAzyme and Fe 3 O 4 nanozyme, respectively, demonstrated by steady‐state kinetic assay. In addition, the catalytic mechanism is jointly disclosed by experimental results and density functional theory studies. The as‐synthesized FeN 5 SAzyme…

Abstract As a wide‐bandgap semiconductor material, titanium dioxide (TiO 2 ), which possesses three crystal polymorphs (i.e., rutile, anatase, and brookite), has gained tremendous attention as a cutting‐edge material for application in the environment and energy fields. Based on the strong attractiveness from its advantages such as high stability, excellent photoelectric properties, and low‐cost fabrication, the construction of high‐performance photodetectors (PDs) based on TiO 2 nanostructures is being extensively developed. An elaborate microtopography and device configuration is the most widely used strategy to achieve efficient TiO 2 ‐based PDs with high photoelectric performances; however, a deep understanding of all the key parameters that influence the behavior of photon‐generated carriers, is also highly required to achieve improved photoelectric performances, as well as their ultimate functional applications. Herein, an in‐depth illustration of the electrical and optical properties of TiO 2 nanostructures in addition to the advances in the technological issues such as…

Abstract Perovskite light-emitting diodes (PeLEDs) own great attention in recent years, due to their narrow emission bandwidth and tunable emission spectrum. Efficient red emission is one of most important part for lighting and display. Quasi-two-dimensional (quasi-2D) perovskite could deliver high emission efficiency due to the strong carrier confinement, while the external quantum efficiencies (EQE) of red quasi-2D PeLEDs are inefficient at present, which is due to the complex distribution of different n-value phases in quasi-2D perovskite films. Here, we finely control the phase distribution of the quasi-2D perovskite by mixing two different large organic cations, which effectively reduce the amount of smaller n index phases, meanwhile the passivation of lead and halide defects in perovskite films is realized. Accordingly, the PeLEDs showed 25.8% EQE and 1300 cd∙m-2 maximum brightness at 680 nm, which exhibit the highest performance for red PeLEDs up to now.

The integrated circuits industry has been continuously producing microelectronic components with ever higher integration level, packaging density, and power density, which demand more stringent requirements for heat dissipation. Electronic packaging materials are used to pack these microelectronic components together, help to dissipate heat, redistribute stresses, and protect the whole system from the environment. They serve an important role in ensuring the performance and reliability of the electronic devices. Among various packaging materials, epoxy-based underfills are often employed in flip-chip packaging. However, widely used capillary underfill materials suffer from their low thermal conductivity, unable to meet the growing heat dissipation required of next-generation IC chips with much higher power density. Many strategies have been proposed to improve the thermal conductivity of epoxy, but its application as underfill materials with complex performance requirements is still difficult. In fact, optimizing the combined thermal-electrical-mechanical-processing properties of…

Abstract H2 evolution is the reason for poor reversibility and limited cycle stability with Zn‐metal anodes, and impedes practical application in aqueous zinc‐ion batteries (AZIBs). Here, using a combined gas chromatography experiment and computation, it is demonstrated that H2 evolution primarily originates from solvated water, rather than free water without interaction with Zn2+. Using linear sweep voltammetry (LSV) in salt electrolytes, H2 evolution is evidenced to occur at a more negative potential than zinc reduction because of the high overpotential against H2 evolution on Zn metal. The hypothesis is tested and, using a glycine additive to reduce solvated water, it is confirmed that H2 evolution and “parasitic” side reactions are suppressed on the Zn anode. This electrolyte additive is evidenced to suppress H2 evolution, reduce corrosion, and give a uniform Zn deposition in Zn|Zn and Zn|Cu cells. It is demonstrated that Zn|PANI (highly conductive polyaniline) full cells exhibit boosted electrochemical performance in 1 M ZnSO4–3 M glycine electrolyte. It is concluded that this…

Liquid crystals have been intensively studied as functional materials. Recently, integration of various disciplines has led to new directions in the design of functional liquid-crystalline materials in the fields of energy, water, photonics, actuation, sensing, and biotechnology. Here, recent advances in functional liquid crystals based on polymers, supramolecular complexes, gels, colloids, and inorganic-based hybrids are reviewed, from design strategies to functionalization of these materials and interfaces. New insights into liquid crystals provided by significant progress in advanced measurements and computational simulations, which enhance new design and functionalization of liquid-crystalline materials, are also discussed.

Abstract Although aqueous Zn batteries have become a more sustainable alternative to lithium‐ion batteries owing to their intrinsic security, their practical applications are limited by dendrite formation and hydrogen reactions. The first application of a rare earth metal type addition to Zn batteries, cerium chloride (CeCl3), as an effective, low‐cost, and green electrolyte additive that facilitates the formation of a dynamic electrostatic shielding layer around the Zn protuberance to induce uniform Zn deposition is presented. After introducing CeCl3 additives, the electrochemical characterizations, in situ optical microscopy observation, in situ differential electrochemical mass spectrometry, along with density functional theory calculations, and finite element method simulations reveal resisted Zn dendritic growth and enhanced electrolyte stability. As a result, the Zn–Zn cells using the CeCl3 additive exhibit a long cycling stability of 2600 h at 2 mA cm−2, an impressive cumulative areal capacity of 3.6 Ah cm−2 at 40 mA cm−2, and a high Coulombic efficiency of ≈99.7%. The fact…

Hole-transporting layers (HTLs) are an essential component in inverted, p-i-n perovskite solar cells (PSCs) where they play a decisive role in extraction and transport of holes, surface passivation, perovskite crystallization, device stability, and cost. Currently, the exploration of efficient, stable, highly transparent and low-cost HTLs is of vital importance for propelling p-i-n PSCs toward commercialization. Compared to their inorganic counterparts, organic HTLs offer multiple advantages such as a tunable bandgap and energy level, easy synthesis and purification, solution processability, and overall low cost. Here, recent progress of organic HTLs, including conductive polymers, small molecules, and self-assembled monolayers, as utilized in inverted PSCs is systematically reviewed and summarized. Their molecular structure, hole-transport properties, energy levels, and relevant device properties and resulting performances are presented and analyzed. A summary of design principles and a future outlook toward highly efficient organic HTLs in inverted PSCs is proposed. This review…

A critical overview of the theory of the chirality-induced spin selectivity (CISS) effect, that is, phenomena in which the chirality of molecular species imparts significant spin selectivity to various electron processes, is provided. Based on discussions in a recently held workshop, and further work published since, the status of CISS effects-in electron transmission, electron transport, and chemical reactions-is reviewed. For each, a detailed discussion of the state-of-the-art in theoretical understanding is provided and remaining challenges and research opportunities are identified.

Information security protection has a tremendous impact on human life, social stability and national security, leading to the rapid development of anti-counterfeiting materials and related techniques. However, the traditional stored information on hard or dry media is often static and lacks functions, which makes it challenging to deal with increasing and powerful counterfeiting technologies. Modified intelligent polymeric gels exhibit color changes and shape morphing under external stimuli, which give them great potential for applications in information storage. This paper provides an overview of the latest progress in polymeric gel-based information storage materials in relation to counterfeiting. Following a brief introduction of anti-counterfeiting materials, the preparation methods for intelligent gels with adjustable colors (e.g., chemical colors and physical colors) and various encryption/decryption modes involving dimensions and diverse colors are outlined. Finally, the challenges and prospects for information storage and anti-counterfeiting based on smart gels are discussed.

Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials. Despite its widespread use, the calculation of BET surface areas causes a spread in reported areas, resulting in reproducibility problems in both academia and industry. To prove this, for this analysis, 18 already-measured raw adsorption isotherms were provided to sixty-one labs, who were asked to calculate the corresponding BET areas. This round-robin exercise resulted in a wide range of values. Here, the reproducibility of BET area determination from identical isotherms is demonstrated to be a largely ignored issue, raising critical concerns over the reliability of reported BET areas. To solve this major issue, a new computational approach to accurately and systematically…

Abstract Lithium–sulfur (Li–S) batteries have been hindered by the shuttle effect and sluggish polysulfide conversion kinetics. Here, a P‐doped nickel tellurium electrocatalyst with Te‐vacancies (P⊂NiTe 2− x ) anchored on maize‐straw carbon (MSC) nanosheets, served as a functional layer (MSC/P⊂NiTe 2− x ) on the separator of high‐performance Li–S batteries. The P⊂NiTe 2− x electrocatalyst enhanced the intrinsic conductivity, strengthened the chemical affinity for polysulfides, and accelerated sulfur redox conversion. The MSC nanosheets enabled NiTe 2 nanoparticle dispersion and Li + diffusion. In situ Raman and ex situ X‐ray absorption spectra confirmed that the MSC/P⊂NiTe 2− x restrained the shuttle effect and accelerated the redox conversion. The MSC/P⊂NiTe 2− x ‐based cell has a cyclability of 637 mAh g ‐1 at 4 C over 1800 cycles with a degradation rate of 0.0139% per cycle, high rate performance of 726 mAh g ‐1 at 6 C, and a high areal capacity of 8.47 mAh cm ‐2 under a sulfur configuration of 10.2 mg cm ‐2 , and a low electrolyte/sulfur usage ratio of 3.9. This work…

Abstract Nitrate electrocatalytic reduction (NO 3 RR) for ammonia production is a promising strategy to close the N‐cycle from nitration contamination, as well as an alternative to the Haber–Bosch process with less energy consumption and carbon dioxide release. However, current long‐term stability of NO 3 RR catalysts is usually tens of hours, far from the requirements for industrialization. Here, symmetry‐broken Cusingle‐atom catalysts are designed, and the catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h −1 cm −2 at an industrial level current density of 366 mA cm −2 is achieved, obtaining a good balance between catalytic activity and long‐term stability. Coordination symmetry breaking is achieved by embedding one Cu atom in graphene nanosheets with two N and two O atoms in the cis ‐configuration, effectively lowering the coordination symmetry, rendering the active site more polar, and accumulating more NO 3 − near the electrocatalyst surface. Additionally, the cis ‐coordination splits the Cu 3d orbitals,…

Abstract Sonodynamic therapy (SDT) exhibits high tissue penetration and negligible radiation damage to normal tissues, and thus emerges as a promising cancer therapeutic modality for glioblastoma (GBM). However, the blood−brain barrier (BBB) and hypoxic microenvironment greatly limit the SDT efficiency. In this work, a biodegradable nanoplatform (termed as CSI) is fabricated by encapsulating catalase (CAT) into silica nanoparticles (CAT@SiO 2 ) for tumor hypoxia relief, and then loaded with the sonosensitizer indocyanine green (ICG). Inspired by the ability of macrophages to cross the BBB, CSI is further coated with AS1411 aptamer‐modified macrophage exosomes to form CSI@Ex‐A, which possesses efficient BBB penetration and good cancer‐cell‐targeting capability. After tumor cell endocytosis, highly expressed glutathione (GSH) triggeres biodegradation of the nanoplatform and the released CAT catalyzes hydrogen peroxide (H 2 O 2 ) to produce O 2 to relieve tumor hypoxia. The GSH depletion and O 2 self‐supplying effectively enhances the SDT efficiency both in vitro and in vivo. In…

The rapid growth of the electronics industry and proliferation of electronic materials and telecommunications technologies has led to the release of a massive amount of untreated electronic waste (e-waste) into the environment. Consequently, catastrophic environmental damage at the microbiome level and serious human health diseases threaten the natural fate of the planet. Currently, the demand for wearable electronics for applications in personalized medicine, electronic skins (e-skins), and health monitoring is substantial and growing. Therefore, "green" characteristics such as biodegradability, self-healing, and biocompatibility ensure the future application of wearable electronics and e-skins in biomedical engineering and bioanalytical sciences. Leveraging the biodegradability, sustainability, and biocompatibility of natural materials will dramatically influence the fabrication of environmentally friendly e-skins and wearable electronics. Here, the molecular and structural characteristics of biological skins and artificial e-skins are discussed. The focus then turns to the…

Abstract Engineering a proper immune response following biomaterial implantation is essential to bone tissue regeneration. Herein, a biomimetically hierarchical scaffold composed of deferoxamine@poly(ε‐caprolactone) nanoparticles (DFO@PCL NPs), manganese carbonyl (MnCO) nanosheets, gelatin methacryloyl hydrogel, and a polylactide/hydroxyapatite (HA) matrix is fabricated to augment bone repair by facilitating the balance of the immune system and bone metabolism. First, a 3D printed stiff scaffold with a well‐organized gradient structure mimics the cortical and cancellous bone tissues; meanwhile, an inside infusion of a soft hydrogel further endows the scaffold with characteristics of the extracellular matrix. A Fenton‐like reaction between MnCO and endogenous hydrogen peroxide generated at the implant‐tissue site triggers continuous release of carbon monoxide and Mn 2+ , thus significantly lessening inflammatory response by upregulating the M2 phenotype of macrophages, which also secretes vascular endothelial growth factor to induce vascular formation. Through activating the…

Abstract Electrolysis of costless and infinite seawater is a promising way toward grid‐scale hydrogen production without causing freshwater stress. Practical potential of this technology, however, is hindered by low energy efficiency and anode corrosion by the detrimental chlorine chemistry in seawater in addition to unaffordable electricity expense. Herein, energy‐saving hydrogen production is reported by chlorine‐free seawater splitting coupling sulfion oxidation. It yields hydrogen at a low cell voltage of 0.97 V, cutting the electricity consumption to 2.32 kWh per m 3 H 2 at 300 mA cm −2 . Compared to alkaline water electrolysis, the energy expense is primarily saved by 60% with 50% lower energy equivalent input. Benefiting from the ultralow cell voltage, the hazardous chlorine chemistry is fully avoided without anode corrosion regardless of Cl − crossover. Meanwhile, it also allows fast degradation of S 2− pollutant from the water body to value‐added sulfur with 80% efficiency, for further reducing hydrogen cost and protection of the ecosystem. Connecting such a hybrid seawater…

Over the last decade, extensive efforts have been made on utilizing advanced materials and structures to improve the properties and functionalities of flexible electronics. While the conventional ways are approaching their natural limits, a revolutionary strategy, namely metamaterials, is emerging toward engineering structural materials to break the existing fetters. Metamaterials exhibit supernatural physical behaviors, in aspects of mechanical, optical, thermal, acoustic, and electronic properties that are inaccessible in natural materials, such as tunable stiffness or Poisson's ratio, manipulating electromagnetic or elastic waves, and topological and programmable morphability. These salient merits motivate metamaterials as a brand-new research direction and have inspired extensive innovative applications in flexible electronics. Here, such a groundbreaking interdisciplinary field is first coined as "flexible metamaterial electronics," focusing on enhancing and innovating functionalities of flexible electronics via the design of metamaterials. Herein, the latest progress and…

The large and rapidly growing family of 2D early transition metal carbides, nitrides, and carbonitrides (MXenes) raises significant interest in the materials science and chemistry of materials communities. Discovered a little more than a decade ago, MXenes have already demonstrated outstanding potential in various applications ranging from energy storage to biology and medicine. The past two years have witnessed increased experimental and theoretical efforts toward studying MXenes' mechanical and tribological properties when used as lubricant additives, reinforcement phases in composites, or solid lubricant coatings. Although research on the understanding of the friction and wear performance of MXenes under dry and lubricated conditions is still in its early stages, it has experienced rapid growth due to the excellent mechanical properties and chemical reactivities offered by MXenes that make them adaptable to being combined with other materials, thus boosting their tribological performance. In this perspective, the most promising results in the area of MXene tribology are…

The number of sensor nodes in the Internet of Things is growing rapidly, leading to a large volume of data generated at sensory terminals. Frequent data transfer between the sensors and computing units causes severe limitations on the system performance in terms of energy efficiency, speed, and security. To efficiently process a substantial amount of sensory data, a novel computation paradigm that can integrate computing functions into sensor networks should be developed. The in-sensor computing paradigm reduces data transfer and also decreases the high computing complexity by processing data locally. Here, the hardware implementation of the in-sensor computing paradigm at the device and array levels is discussed. The physical mechanisms that lead to unique sensory response characteristics and their corresponding computing functions are illustrated. In particular, bioinspired device characteristics enable the implementation of the functionalities of neuromorphic computation. The integration technology is also discussed and the perspective on the future development of in-sensor…

Whilst the photocatalytic technique is considered to be one of the most significant routes to address the energy crisis and global environmental challenges, the solar-to-chemical conversion efficiency is still far from satisfying practical industrial requirements, which can be traced to the suboptimal bandgap and electronic structure of photocatalysts. Strain engineering is a universal scheme that can finely tailor the bandgap and electronic structure of materials, hence supplying a novel avenue to boost their photocatalytic performance. Accordingly, to explore promising directions for certain breakthroughs in strained photocatalysts, an overview on the recent advances of strain engineering from the basics of strain effect, creations of strained materials, as well as characterizations and simulations of strain level is provided. Besides, the potential applications of strain engineering in photocatalysis are summarized, and a vision for the future controllable-electronic-structure photocatalysts by strain engineering is also given. Finally, perspectives on the challenges for future…

Atmospheric water harvesting (AWH) is emerging as a promising strategy to produce fresh water from abundant airborne moisture to overcome the global clean water shortage. The ubiquitous moisture resources allow AWH to be free from geographical restrictions and potentially realize decentralized applications, making it a vital parallel or supplementary freshwater production approach to liquid water resource-based technologies. Recent advances in regulating chemical properties and micro/nanostructures of moisture-harvesting materials have demonstrated new possibilities to promote enhanced device performance and new understandings. This perspective aims to provide a timely overview on the state-of-the-art materials design and how they serve as the active components in AWH. First, the key processes of AWH, including vapor condensation, droplet nucleation, growth, and departure are outlined, and the desired material properties based on the fundamental mechanisms are discussed. Then, how tailoring materials-water interactions at the molecular level play a vital role in realizing high water…

Abstract The poor Zn reversibility has been criticized for limiting applications of aqueous Zn‐ion batteries (ZIBs); however, its behavior in aqueous media is not fully uncovered yet. Here, this knowledge gap is addressed, indicating that Zn electrodes face a O 2 ‐involving corrosion, besides H 2 evolution and dendrite growth. Differing from aqueous Li/Na batteries, removing O 2 cannot enhance ZIB performance because of the aggravated competing H 2 evolution. To address Zn issues, a one‐off electrolyte strategy is reported by introducing the triple‐function C 3 H 7 Na 2 O 6 P, which can take effects during the shelf time of battery. It regulates H + concentration and reduces free‐water activity, inhibiting H 2 evolution. A self‐healing solid/electrolyte interphase (SEI) can be triggered before battery operation, which suppresses O 2 adsorption corrosion and dendritic deposition. Consequently, a high Zn reversibility of 99.6% is achieved under a high discharge depth of 85%. The pouch full‐cell with a lean electrolyte displays a record lifespan with capacity retention of 95.5% after…

As a class of porous materials with crystal lattices, metal-organic frameworks (MOFs), featuring outstanding specific surface area, tunable functionality, and versatile structures, have attracted huge attention in the past two decades. Since the first conductive MOF is successfully synthesized in 2009, considerable progress has been achieved for the development of conductive MOFs, allowing their use in diverse applications for electrochemical energy storage. Among those applications, supercapacitors have received great interest because of their high power density, fast charging ability, and excellent cycling stability. Here, the efforts hitherto devoted to the synthesis and design of conductive MOFs and their auspicious capacitive performance are summarized. Using conductive MOFs as a unique platform medium, the electronic and molecular aspects of the energy storage mechanism in supercapacitors with MOF electrodes are discussed, highlighting the advantages and limitations to inspire new ideas for the development of conductive MOFs for supercapacitors.

Photoresponsive supramolecular polymers are well-organized assemblies based on highly oriented and reversible noncovalent interactions containing photosensitive molecules as (co-)monomers. They have attracted increasing interest in smart materials and dynamic systems with precisely controllable functions, such as light-driven soft actuators, photoresponsive fluorescent anticounterfeiting and light-triggered electronic devices. The present review discusses light-activated molecules used in photoresponsive supramolecular polymers with their main photo-induced changes, e.g., geometry, dipole moment, and chirality. Based on these distinct changes, supramolecular polymers formed by light-activated molecules exhibit photoresponsive disassembly and reassembly. As a consequence, photo-induced supramolecular polymerization, "depolymerization," and regulation of the lengths and topologies are observed. Moreover, the light-controlled functions of supramolecular polymers, such as actuation, emission, and chirality transfer along length scales, are highlighted. Furthermore, a perspective on…

Abstract Electrocatalytic hydrogen peroxide (H 2 O 2 ) synthesis via the two‐electron oxygen reduction reaction (2e ORR) pathway is becoming increasingly important due to the green production process. Here, cationic vacancies on nickel phosphide, as a proof‐of‐concept to regulate the catalyst's physicochemical properties, are introduced for efficient H 2 O 2 electrosynthesis. The as‐fabricated Ni cationic vacancies (V Ni )‐enriched Ni 2− x P‐V Ni electrocatalyst exhibits remarkable 2e ORR performance with H 2 O 2 molar fraction of >95% and Faradaic efficiencies of >90% in all pH conditions under a wide range of applied potentials. Impressively, the as‐created V Ni possesses superb long‐term durability for over 50 h, suppassing all the recently reported catalysts for H 2 O 2 electrosynthesis. Operando X‐ray absorption near‐edge spectroscopy (XANES) and synchrotron Fourier transform infrared (SR‐FTIR) combining theoretical calculations reveal that the excellent catalytic performance originates from the V Ni ‐induced geometric and electronic structural optimization, thus promoting…

The well-established proton exchange membrane (PEM)-based water electrolysis, which operates under acidic conditions, possesses many advantages compared to alkaline water electrolysis, such as compact design, higher voltage efficiency, and higher gas purity. However, PEM-based water electrolysis is hampered by the low efficiency, instability, and high cost of anodic electrocatalysts for the oxygen evolution reaction (OER). In this review, the recently reported acidic OER electrocatalysts are comprehensively summarized, classified, and discussed. The related fundamental studies on OER mechanisms and the relationship between activity and stability are particularly highlighted in order to provide an atomistic-level understanding for OER catalysis. A stability test protocol is suggested to evaluate the intrinsic activity degradation. Some current challenges and unresolved questions, such as the usage of carbon-based materials and the differences between the electrocatalyst performances in acidic electrolytes and PEM-based electrolyzers are also discussed. Finally, suggestions for the…

Abstract Perovskite/silicon tandem solar cells are promising avenues for achieving high‐performance photovoltaics with low costs. However, the highest certified efficiency of perovskite/silicon tandem devices based on economically matured silicon heterojunction technology (SHJ) with fully textured wafer is only 25.2% due to incompatibility between the limitation of fabrication technology which is not compatible with the production‐line silicon wafer. Here, a molecular‐level nanotechnology is developed by designing NiO x /2PACz ([2‐(9H‐carbazol‐9‐yl) ethyl]phosphonic acid) as an ultrathin hybrid hole transport layer (HTL) above indium tin oxide (ITO) recombination junction, to serve as a vital pivot for achieving a conformal deposition of high‐quality perovskite layer on top. The NiO x interlayer facilitates a uniform self‐assembly of 2PACz molecules onto the fully textured surface, thus avoiding direct contact between ITO and perovskite top‐cell for a minimal shunt loss. As a result of such interfacial engineering, the fully textured perovskite/silicon tandem cells obtain a…

Abstract Ruthenium (Ru)‐based electrocatalysts as platinum (Pt) alternatives in catalyzing hydrogen evolution reaction (HER) are promising. However, achieving efficient reaction processes on Ru catalysts is still a challenge, especially in alkaline media. Here, the well‐dispersed Ru nanoparticles with adjacent Ru single atoms on carbon substrate (Ru 1,n ‐NC) is demonstrated to be a superb electrocatalyst for alkaline HER. The obtained Ru 1,n ‐NC exhibits ultralow overpotential (14.8 mV) and high turnover frequency (1.25 H 2 s ‐1 at −0.025 V vs reversible hydrogen electrode), much better than the commercial 40 wt.% Pt/C. The analyses reveal that Ru nanoparticles and single sites can promote each other to deliver electrons to the carbon substrate. Eventually, the electronic regulations bring accelerated water dissociation and reduced energy barriers of hydroxide/hydrogen desorption on adjacent Ru sites, then an optimized reaction kinetics for Ru 1,n ‐NC is obtained to achieve superb hydrogen generation in alkaline media. This work provides a new insight into the catalyst design in…

Abstract Near‐infrared (NIR) luminescence materials with broadband emissions are necessary for the development of light‐emitting diodes (LEDs) based light sources. However, most known NIR‐emitting materials are limited by their low external quantum efficiency. This work demonstrates how the photoluminescence quantum efficiency of europium‐activated calcium oxide (CaO:Eu) NIR phosphor can be significantly improved and stabilized at operating temperatures of LEDs. A carbon paper wrapping technology is innovatively developed and used during the solid‐state sintering to promote the reduction of Eu 3+ into Eu 2+ . In parallel, the oxygen vacancies in the CaO lattice are repaired utilizing GeO 2 decomposition. Through this process, a record‐high external quantum efficiency of 54.7% at 740 nm is obtained with a thermal stability greatly improved from 57% to 90% at 125 °C. The as‐fabricated NIR‐LEDs reach record photoelectric efficiency (100 mA@23.4%) and output power (100 mA @ 319.5 mW). This discovery of high‐performance phosphors will open new research avenues for broadband NIR LED light…

Tuning the reactivity of lattice oxygen is of significance for lowering the energy barriers and accelerating the oxygen evolution reaction (OER). Herein, single-atomic Mo sites are anchored on Ni-Fe oxyhydroxide nanoarrays by a facile metal-organic-framework-derived strategy, exhibiting superior performance toward the OER in alkaline media. In situ electrochemical spectroscopy and isotope-labeling experiments reveal the involvement of lattice oxygen during OER cycles. Combining theoretical and experimental investigations of the electronic configuration, it is comprehensively confirmed that the incorporation of single-atomic Mo sites enables higher oxidation state of the metal and strengthened metal-oxygen hybridization, as well as the formation of oxidized ligand holes above the Fermi level. In a word, the considerable acceleration of water oxidation is achieved via enhancing the reactivity of lattice oxygen and triggering the lattice oxygen activation. This work may provide new insights for designing ideal electrocatalysts via tuning the chemical state and activating the anions…

Abstract The electroreduction of nitrate (NO 3 − ) pollutants to ammonia (NH 3 ) offers an alternative approach for both wastewater treatment and NH 3 synthesis. Numerous electrocatalysts have been reported for the electroreduction of NO 3 − to NH 3 , but most of them demonstrate poor performance at ultralow NO 3 − concentrations. In this study, a Cu‐based catalyst for electroreduction of NO 3 − at ultralow concentrations is developed by encapsulating Cu nanoparticles in a porous carbon framework (Cu@C). At −0.3 V vs reversible hydrogen electrode (RHE), Cu@C achieves Faradaic efficiency for NH 3 of 72.0% with 1 × 10 −3 m NO 3 − , which is 3.6 times higher than that of Cu nanoparticles. Notably, at −0.9 V vs RHE, the yield rate of NH 3 for Cu@C is 469.5 µg h −1 cm −2 , which is the highest value reported for electrocatalysts with 1 × 10 −3 m NO 3 − . An investigation of the mechanism reveals that NO 3 − can be concentrated owing to the enrichment effect of the porous carbon framework in Cu@C, thereby facilitating the mass transfer of NO 3 − for efficient electroreduction into NH 3 at…

Abstract Halide perovskites have shown superior potentials in flexible photovoltaics due to their soft and high power‐to‐weight nature. However, interfacial residual stress and lattice mismatch due to the large deformation of flexible substrates have greatly limited the performance of flexible perovskite solar cells (F‐PSCs). Here, ammonium formate (HCOONH 4 ) is used as a pre‐buried additive in electron transport layer (ETL) to realize a bottom‐up infiltration process for an in situ, integral modification of ETL, perovskite layer, and their interface. The HCOONH 4 treatment leads to an enhanced electron extraction in ETL, relaxed residual strain and micro‐strain in perovskite film, along with reduced defect densities within these layers. As a result, a top power conversion efficiency of 22.37% and a certified 21.9% on F‐PSCs are achieved, representing the highest performance reported so far. This work links the critical connection between multilayer mechanics/defect profiles of ETL‐perovskite structure and device performance, thus providing meaningful scientific direction to…

Energy harvesting modules play an increasingly important role in the development of autonomous self-powered microelectronic devices. MXenes (i.e., 2D transition metal carbide/nitride) have recently emerged as promising candidates for energy applications due to their excellent electronic conductivity, large specific surface area, and tunable properties. Herein, a perspective on using MXenes to harvest energy from various sources in the environment is presented. First, the characteristics of MXenes that facilitate energy capturing are systematically introduced and the preparation strategies of MXenes and their derived nanostructures tailored toward such applications are summarized. Subsequently, the harvesting mechanism of different energy sources (e.g., solar energy, thermoelectric energy, triboelectric energy, piezoelectric energy, salinity-gradient energy, electrokinetic energy, ultrasound energy, and humidity energy) are discussed. Then, the recent progress of MXene-based nanostructures in energy harvesting, as well as their applications, is introduced. Finally, opinions on the…

Abstract Delivering sufficient water to the evaporation surface/interface is one of the most widely adopted strategies to overcome salt accumulation in solar‐driven interfacial desalination. However, water transport and heat conduction loss are positively correlated, resulting in the trade‐off between thermal localization and salt resistance. Herein, a 3D hydrogel evaporator with vertical radiant vessels is prepared to surmount the long‐standing trade‐off, thereby achieving high‐rate and stable solar desalination of high‐salinity. Experiments and numerical simulations reveal that the unique hierarchical structure, which consists of a large vertical vessel channel, radiant vessels, and porous vessel walls, facilitates strong self‐salt‐discharge and low longitudinal thermal conductivity. With the structure employed, a groundbreaking comprehensive performance, under one sun illumination, of evaporation rate as high as 3.53 kg m −2 h −1 , salinity of 20 wt%, and a continuous 8 h evaporation is achieved, which thought to be the best reported result from a salt‐free system. This work…

This review highlights the unique techniques for patterning liquid metals containing gallium (e.g., eutectic gallium indium, EGaIn). These techniques are enabled by two unique attributes of these liquids relative to solid metals: 1) The fluidity of the metal allows it to be injected, sprayed, and generally dispensed. 2) The solid native oxide shell allows the metal to adhere to surfaces and be shaped in ways that would normally be prohibited due to surface tension. The ability to shape liquid metals into non-spherical structures such as wires, antennas, and electrodes can enable fluidic metallic conductors for stretchable electronics, soft robotics, e-skins, and wearables. The key properties of these metals with a focus on methods to pattern liquid metals into soft or stretchable devices are summari.

Abstract Scintillators with high spatial resolution at a low radiation dose rate are desirable for X‐ray medical imaging. To challenge the state‐of‐art technology, it is necessary to design large‐area wafers with high light yield, oriented light transport, and reduced light scattering. Here, a seed‐crystal‐induced cold sintering is adopted and a <001>‐textured TPP 2 MnBr 4 (TPP: tetraphenylphosphonium) transparent ceramic is fabricated with a large‐area wafer of 5 cm in diameter, exhibiting high optical transparency of above 68% over the 450–600 nm range. The compelling scintillation performance of the TPP 2 MnBr 4 wafer includes a light yield of ≈78 000 ± 2000 photons per MeV, a low detection limit 8.8 nanograys per second, about 625 times lower than the requirement of X‐ray diagnostics (5500 nanograys per second), and an energy resolution of 17% for high‐energy γ‐rays (662 keV). X‐ray imaging demonstrates a high spatial resolution of 15.7 lp mm −1 . Moreover, the designed material exhibits good retention of the radioluminescence intensity and light yield. This work presents a…

Mechanochemistry with solvent-free and environmentally friendly characteristics is one of the most promising alternatives to traditional liquid-phase-based reactions, demonstrating epoch-making significance in the realization of different types of chemistry. Mechanochemistry utilizes mechanical energy to promote physical and chemical transformations to design complex molecules and nanostructured materials, encourage dispersion and recombination of multiphase components, and accelerate reaction rates and efficiencies via highly reactive surfaces. In particular, mechanochemistry deserves special attention because it is capable of endowing energy materials with unique characteristics and properties. Herein, the latest advances and progress in mechanochemistry for the preparation and modification of energy materials are reviewed. An outline of the basic knowledge, methods, and characteristics of different mechanochemical strategies is presented, distinguishing this review from most mechanochemistry reviews that only focus on ball-milling. Next, this outline is followed by a detailed and…

Abstract High‐color‐purity blue and green organic light‐emitting diodes (OLEDs) have been resolved thanks to the development of B/N‐based polycyclic multiple resonance (MR) emitters. However, due to the derivatization limit of B/N polycyclic structures, the design of red MR emitters remains challenging. Herein, a series of novel red MR emitters is reported by para ‐positioning N–π–N, O–π–O, B–π–B pairs onto a benzene ring to construct an MR central core. These emitters can be facilely and modularly synthesized, allowing for easy fine‐tuning of emission spectra by peripheral groups. Moreover, these red MR emitters display excellent photophysical properties such as near‐unity photoluminescence quantum yield (PLQY), fast radiative decay rate ( k r ) up to 7.4 × 10 7 s −1 , and most importantly, narrowband emission with full‐width at half‐maximum (FWHM) of 32 nm. Incorporating these MR emitters, pure red OLEDs sensitized by phosphor realize state‐of‐the‐art device performances with external quantum efficiency (EQE) exceeding 36%, ultralow efficiency roll‐off (EQE remains as high as…

Research on organic solar cells (OSCs) has progressed through material innovation and device engineering. However, well-known and ubiquitous intermolecular interactions, and particularly their synergistic effects, have received little attention. Herein, the complicated relationship between photovoltaic conversion and multidimensional intermolecular interactions in the active layers is investigated. These interactions are dually regulated by side-chain isomerization and end-cap engineering of the acceptors. The phenylalkyl featured acceptors (LA-series) exhibit stronger crystallinity with preferential face-on interactions relative to the alkylphenyl attached isomers (ITIC-series). In addition, the PM6 and LA-series acceptors exhibit moderate donor/acceptor interactions compared to those of the strongly interacting PM6/ITIC-series pairs, which helps to enhance phase separation and charge transport. Consequently, the output efficiencies of all LA series acceptors are over 14%. Moreover, LA-series acceptors show appropriate compatibility, host/guest interactions, and crystallinity…

Abstract Tackling the huge volume expansion of silicon (Si) anode desires a stable solid electrolyte interphase (SEI) to prohibit the interfacial side reactions. Here, a layered conductive polyaniline (LCP) coating is built on Si nanoparticles to achieve high areal capacity and long lifespan. The conformal LCP coating stores electrolyte in interlamination spaces and directs an in situ formation of LCP‐integrated hybrid SEI skin with uniform distribution of organic and inorganic components, enhancing the flexibility of the SEI to buffer the volume changes and maintaining homogeneous ion transport during cycling. As a result, the Si anode shows a remarkable cycling stability under high areal capacity (≈3 mAh cm −2 ) after 150 cycles and good rate performance of 942 mAh g −1 at 5 A g −1 . This work demonstrates the great potential of regulating the SEI properties by a layered polymer‐directing SEI formation for the mechanical and electrochemical stabilization of Si anodes.

Phase-change materials (PCMs) offer tremendous potential to store thermal energy during reversible phase transitions for state-of-the-art applications. The practicality of these materials is adversely restricted by volume expansion, phase segregation, and leakage problems associated with conventional solid-liquid PCMs. Solid-solid PCMs, as promising alternatives to solid-liquid PCMs, are gaining much attention toward practical thermal-energy storage (TES) owing to their inimitable advantages such as solid-state processing, negligible volume change during phase transition, no contamination, and long cyclic life. Herein, the aim is to provide a holistic analysis of solid-solid PCMs suitable for thermal-energy harvesting, storage, and utilization. The developing strategies of solid-solid PCMs are presented and then the structure-property relationship is discussed, followed by potential applications. Finally, an outlook discussion with momentous challenges and future directions is presented. Hopefully, this review will provide a guideline to the scientific community to develop…

Abstract The regulation of atomic and electronic structures of active sites plays an important role in the rational design of oxygen evolution reaction (OER) catalysts toward electrocatalytic hydrogen generation. However, the precise identification of the active sites for surface reconstruction behavior during OER remains elusive for water‐alkali electrolysis. Herein, irreversible reconstruction behavior accompanied by copper dynamic evolution for cobalt iron layered double hydroxide (CoFe LDH) precatalyst to form CoFeCuOOH active species with high‐valent Co species is reported, identifying the origin of reconstructed active sites through operando UV‐Visible (UV–vis), in situ Raman, and X‐ray absorption fine‐structure (XAFS) spectroscopies. Density functional theory analysis rationalizes this typical electronic structure evolution causing the transfer of intramolecular electrons to form ligand holes, promoting the reconstruction of active sites. Specifically, unambiguous identification of active sites for CoFeCuOOH is explored by in situ 18 O isotope‐labeling differential…

Lithium metal batteries (LMBs) are considered promising candidates for next-generation battery systems due to their high energy density. However, commercialized carbonate electrolytes cannot be used in LMBs due to their poor compatibility with lithium metal anodes. While increasing cut-off voltage is an effective way to boost the energy density of LMBs, conventional ethylene carbonate-based electrolytes undergo a number of side reactions at high voltages. It is therefore critical to upgrade conventional carbonate electrolytes, the performance of which is highly influenced by the solvation structure of lithium ions (Li+). This review provides a comprehensive overview of the strategies to regulate the solvation structure of Li+ in carbonate electrolytes for LMBs by better understanding the science behind the Li+ solvation structure and Li+ behavior. Different strategies are systematically compared to help select better electrolytes for specific applications. The remaining scientific and technical problems are pointed out, and directions for future research on carbonate electrolytes…

Abstract Solar‐driven water evaporation technology holds great potential for mitigating the global water scarcity due to its high energy conversion efficiency. Lowering the vaporization enthalpy of water is key to boost the performance of solar‐driven desalination. Herein, a highly hydratable hydrogel (PMH) network, consisting of modified needle coke as photothermal material and polyvinyl alcohol (PVA) as hydratable matrix, is crafted via simple physical cross‐linking method. When capitalizing on the PMH as evaporator for 3.5 wt% NaCl solution, a high evaporation rate of 3.18 kg m−2 h−1 under one sun illumination is deliver ed, unexpectedly outperforming that in pure water (2.53 kg m−2 h−1). More importantly, the PMH shows a robust desalination durability, thus enabling a self‐cleaning system. Further investigations reveal that the outstanding evaporation performance of PMH in brine roots in its hydrability tuned by chaotropic Cl−, wherein the Cl− can mediate the hydration chemistry of PVA in PMH and suppress related crystallinity, thus contributing to the increased content of…

Abstract A compatible and robust electrode–electrolyte interface is favorable in resolving the severe dendritic growth and side reactions of aqueous Zn‐ion batteries toward commercial‐standard lifespan and charging–discharging rate. Herein, a chemical welding strategy through in situ construction of a gel electrolyte that enables Zn‐ion batteries to achieve ultralong life and reversibility is reported. The gel electrolyte is spontaneously formed on the Zn anode surface by redox polymerization with the initiation of Zn metal. The direct participation of the Zn anode in the chemical synthesis of the gel electrolyte brings a well‐bonded and water‐poor electrode–electrolyte interface, which not only alleviates side reactions but also enables preferential (002) Zn deposition. The in situ symmetric cell thus prepared delivers an ultralong lifespan of 5100 h (>212 days), and a hybrid capacitor with the in situ electrolyte runs smoothly over 40 000 cycles at 20 A g−1. Even at an ultrahigh current density of 40 mA cm−2 and capacity of 40 mAh cm−2, the cell still operates stably for 240 h,…

Abstract The control of multimetallic ensembles at the atomic‐level is challenging, especially for high‐entropy alloys (HEAs) possessing five or more elements. Herein, the one‐pot synthesis of hexagonal‐close‐packed ( hcp ) PtRhBiSnSb high‐entropy intermetallic (HEI) nanoplates with intrinsically isolated Pt, Rh, Bi, Sn, and Sb atoms is reported, to boost the electrochemical oxidation of liquid fuels. Taking advantage of these combined five metals, the well‐defined PtRhBiSnSb HEI nanoplates exhibit a remarkable mass activity of 19.529, 15.558, and 7.535 A mg −1 Pt+Rh toward the electrooxidation of methanol, ethanol, and glycerol in alkaline electrolytes, respectively, representing a state‐of‐the‐art multifunctional electrocatalyst for alcohol oxidation reactions. In particular, the PtRhBiSnSb HEI achieves record‐high methanol oxidation reaction (MOR) activity in an alkaline environment. Theoretical calculations demonstrate that the introduction of the fifth metal Rh enhances the electron‐transfer efficiency in PtRhBiSnSb HEI nanoplates, which contributes to the improved oxidation…

DNA materials have emerged as potential nanocarriers for targeted cancer therapy to precisely deliver cargos with specific purposes. The short half-life and low bioavailability of DNA materials due to their interception by the reticuloendothelial system and blood clearance further limit their clinical translation. This study employs an HER2-targeted DNA-aptamer-modified DNA tetrahedron (HApt-tFNA) as a drug delivery system, and combines maytansine (DM1) to develop the HApt-DNA tetrahedron/DM1 conjugate (HApt-tFNA@DM1, HTD, HApDC) for targeted therapy of HER2-positive cancer. To optimize the pharmacokinetics and tumor-aggregation of HTD, a biomimetic camouflage is applied to embed HTD. The biomimetic camouflage is constructed by merging the erythrocyte membrane with pH-responsive functionalized synthetic liposomes, thus with excellent performance of drug delivery and tumor-stimulated drug release. The hybrid erythrosome-based nanoparticles show better inhibition of HER2-positive cancer than other drug formulations and exhibit superior biosafety. With the strengths of precise…

Eutectic gallium-indium (EGaIn), a liquid metal with a melting point close to or below room temperature, has attracted extensive attention in recent years due to its excellent properties such as fluidity, high conductivity, thermal conductivity, stretchability, self-healing capability, biocompatibility, and recyclability. These features of EGaIn can be adjusted by changing the experimental condition, and various composite materials with extended properties can be further obtained by mixing EGaIn with other materials. In this review, not only the are unique properties of EGaIn introduced, but also the working principles for the EGaIn-based devices are illustrated and the developments of EGaIn-related techniques are summarized. The applications of EGaIn in various fields, such as flexible electronics (sensors, antennas, electronic circuits), molecular electronics (molecular memory, opto-electronic switches, or reconfigurable junctions), energy catalysis (heat management, motors, generators, batteries), biomedical science (drug delivery, tumor therapy, bioimaging and neural interfaces)…

Abstract Rechargeable aqueous Zn–Mn batteries have garnered extensive attention for next‐generation high‐safety energy storage. However, the charge‐storage chemistry of Zn–Mn batteries remains controversial. Prevailing mechanisms include conversion reaction and cation (de)intercalation in mild acid or neutral electrolytes, and a MnO 2 /Mn 2+ dissolution−deposition reaction in strong acidic electrolytes. Herein, a Zn 4 SO 4 ·(OH) 6 · x H 2 O (ZSH)‐assisted deposition−dissolution model is proposed to elucidate the reaction mechanism and capacity origin in Zn–Mn batteries based on mild acidic sulfate electrolytes. In this new model, the reversible capacity originates from a reversible conversion reaction between ZSH and Zn x MnO(OH) 2 nanosheets in which the MnO 2 initiates the formation of ZSH but contributes negligibly to the apparent capacity. The role of ZSH in this new model is confirmed by a series of operando characterizations and by constructing Zn batteries using other cathode materials (including ZSH, ZnO, MgO, and CaO). This research may refresh the understanding of the most…

On-skin electronics that offer revolutionary capabilities in personalized diagnosis, therapeutics, and human-machine interfaces require seamless integration between the skin and electronics. A common question remains whether an ideal interface can be introduced to directly bridge thin-film electronics with the soft skin, allowing the skin to breathe freely and the skin-integrated electronics to function stably. Here, an ever-thinnest hydrogel is reported that is compliant to the glyphic lines and subtle minutiae on the skin without forming air gaps, produced by a facile cold-lamination method. The hydrogels exhibit high water-vapor permeability, allowing nearly unimpeded transepidermal water loss and free breathing of the skin underneath. Hydrogel-interfaced flexible (opto)electronics without causing skin irritation or accelerated device performance deterioration are demonstrated. The long-term applicability is recorded for over one week. With combined features of extreme mechanical compliance, high permeability, and biocompatibility, the ultrathin hydrogel interface promotes the…

Abstract Growth of dendrites, the low plating/stripping efficiency of Zn anodes, and the high freezing point of aqueous electrolytes hinder the practical application of aqueous Zn‐ion batteries. Here, a zwitterionic osmolyte‐based molecular crowding electrolyte is presented, by adding betaine (Bet, a by‐product from beet plant) to the aqueous electrolyte, to solve the abovementioned problems. Substantive verification tests, density functional theory calculations, and ab initio molecular dynamics simulations consistently reveal that side reactions and growth of Zn dendrites are restrained because Bet can break Zn2+ solvation and regulate oriented 2D Zn2+ deposition. The Bet/ZnSO4 electrolyte enables superior reversibility in a Zn–Cu half‐cell to achieve a high Coulombic efficiency >99.9% for 900 cycles (≈1800 h), and dendrite‐free Zn plating/stripping in Zn–Zn cells for 4235 h at 0.5 mA cm−2 and 0.5 mAh cm−2. Furthermore, a high concentration of Bet lowers the freezing point of the electrolyte to −92 °C via the molecular‐crowding effect, which ensures the stable operation of the…

Abstract The piezo‐assisted photocatalysis system, which can utilize solar energy and mechanical energy simulteneously, is promising but still challenging in the environmental remediation field. In this work, a novel metal–semiconductor BaTiO3@ReS2 Schottky heterostructure is designed and it shows high‐efficiency on piezo‐assisted photocatalytic molecular oxygen activation. By combining experiment and calculation results, the distorted metal‐phase ReS2 nanosheets are found to be closely anchored on the surface of the BaTiO3 nanorods, through interfacial ReO covalent bonds. The Schottky heterostructure not only forms electron‐transfer channels but also exhibits enhanced oxygen activation capacity, which are helpful to produce more superoxide radicals. The polarization field induced by the piezoelectric BaTiO3 can lower the Schottky barrier and thus reduce the transfer resistance of photogenerated electrons directing to the ReS2. As a result of the synergy effect between the two components, the BaTiO3@ReS2 exhibits untrahigh activity for degradation of pollutants with an apparent…

Strain engineering is a promising way to tune the electrical, electrochemical, magnetic, and optical properties of 2D materials, with the potential to achieve high-performance 2D-material-based devices ultimately. This review discusses the experimental and theoretical results from recent advances in the strain engineering of 2D materials. Some novel methods to induce strain are summarized and then the tunable electrical and optical/optoelectronic properties of 2D materials via strain engineering are highlighted, including particularly the previously less-discussed strain tuning of superconducting, magnetic, and electrochemical properties. Also, future perspectives of strain engineering are given for its potential applications in functional devices. The state of the survey presents the ever-increasing advantages and popularity of strain engineering for tuning properties of 2D materials. Suggestions and insights for further research and applications in optical, electronic, and spintronic devices are provided.