The 100 most-cited articles in Angewandte Chemie, 2020

Abstract Rechargeable aqueous zinc batteries (RAZB) have been re‐evaluated because of the superiority in addressing safety and cost concerns. Nonetheless, the limited lifespan arising from dendritic electrodeposition of metallic Zn hinders their further development. Herein, a metal–organic framework (MOF) was constructed as front surface layer to maintain a super‐saturated electrolyte layer on the Zn anode. Raman spectroscopy indicated that the highly coordinated ion complexes migrating through the MOF channels were different from the solvation structure in bulk electrolyte. Benefiting from the unique super‐saturated front surface, symmetric Zn cells survived up to 3000 hours at 0.5 mA cm−2, near 55‐times that of bare Zn anodes. Moreover, aqueous MnO2–Zn batteries delivered a reversible capacity of 180.3 mAh g−1and maintained a high capacity retention of 88.9 % after 600 cycles with MnO2mass loading up to 4.2 mg cm−2.

Abstract X‐ray photoelectron spectroscopy (XPS) is an indispensable technique in modern materials science for the determination of chemical bonding as evidenced by more than 10 000 XPS papers published annually. A literature survey reveals that in the vast majority of cases an incorrect referencing of the binding energy scale is used, neglecting warnings that have been formulated from the early days of the technique. Consequences for the data reliability are disastrous and decades of XPS work require revisiting. The purpose of this Viewpoint is to highlight the existing problems, review the criticism and suggest ways forward.

Abstract To date, copper is the only monometallic catalyst that can electrochemically reduce CO 2 into high value and energy‐dense products, such as hydrocarbons and alcohols. In recent years, great efforts have been directed towards understanding how its nanoscale structure affects activity and selectivity for the electrochemical CO 2 reduction reaction (CO 2 RR). Furthermore, many attempts have been made to improve these two properties. Nevertheless, to advance towards applied systems, the stability of the catalysts during electrolysis is of great significance. This aspect, however, remains less investigated and discussed across the CO 2 RR literature. In this Minireview, the recent progress on understanding the stability of copper‐based catalysts is summarized, along with the very few proposed degradation mechanisms. Finally, our perspective on the topic is given.

Abstract Single‐atom CoN 4 active sites have demonstrated excellent efficiency in peroxymonosulfate activation. However, the identification of CoN 4 active sites and the detailed singlet oxygen generation mechanism in peroxymonosulfate activation remains ambiguous. We demonstrate a strategy to regulate the generation of reactive oxygen species by atomically dispersed cobalt anchored on nitrogen‐doped carbon. As indicated by experiment and DFT calculations, CoN 2+2 was the active site and singlet oxygen was the predominant reactive oxygen species with a proportion of 98.89 %. Spontaneous dissociation of adsorbed peroxymonosulfate on the CoN 2+2 active sites was energetically unfavorable because of the weakly positive Co atoms and CoN 2+2 coordination, which directed PMS oxidation by a non‐radical pathway and with simultaneous singlet oxygen generation. The generated singlet oxygen degraded several organic pollutants with high efficiency across a broad pH range.

Abstract Two‐dimensional (2D) nanomaterials are currently explored as novel photothermal agents because of their ultrathin structure, high specific surface area, and unique optoelectronic properties. In addition to single photothermal therapy (PTT), 2D nanomaterials have demonstrated significant potential in PTT‐based synergistic therapies. In this Minireview, we summarize the recent progress in 2D nanomaterials for enhanced photothermal cancer therapy over the last five years. Their unique optical properties, typical synthesis methods, and surface modification are also covered. Emphasis is placed on their PTT and PTT‐synergized chemotherapy, photodynamic therapy, and immunotherapy. The major challenges of 2D photothermal agents are addressed and the promising prospects are also presented.

Abstract Unveiling the active phase of catalytic materials under reaction conditions is important for the construction of efficient electrocatalysts for selective nitrate reduction to ammonia. The origin of the prominent activity enhancement for CuO (Faradaic efficiency: 95.8 %, Selectivity: 81.2 %) toward selective nitrate electroreduction to ammonia was probed. 15N isotope labeling experiments showed that ammonia originated from nitrate reduction. 1H NMR spectroscopy and colorimetric methods were performed to quantify ammonia. In situ Raman and ex situ experiments revealed that CuO was electrochemically converted into Cu/Cu2O, which serves as an active phase. The combined results of online differential electrochemical mass spectrometry (DEMS) and DFT calculations demonstrated that the electron transfer from Cu2O to Cu at the interface could facilitate the formation of *NOH intermediate and suppress the hydrogen evolution reaction, leading to high selectivity and Faradaic efficiency.

Abstract Single‐atom catalysts (SACs) have great potential in electrocatalysis. Their performance can be rationally optimized by tailoring the metal atoms, adjacent coordinative dopants, and metal loading. However, doing so is still a great challenge because of the limited synthesis approach and insufficient understanding of the structure–property relationships. Herein, we report a new kind of Mo SAC with a unique O,S coordination and a high metal loading over 10 wt %. The isolation and local environment was identified by high‐angle annular dark‐field scanning transmission electron microscopy and extended X‐ray absorption fine structure. The SACs catalyze the oxygen reduction reaction (ORR) via a 2 e− pathway with a high H2O2 selectivity of over 95 % in 0.10 m KOH. The critical role of the Mo single atoms and the coordination structure was revealed by both electrochemical tests and theoretical calculations.

Abstract P2‐type layered oxides suffer from an ordered Na+/vacancy arrangement and P2→O2/OP4 phase transitions, leading them to exhibit multiple voltage plateaus upon Na+ extraction/insertion. The deficient sodium in the P2‐type cathode easily induces the bad structural stability at deep desodiation states and limited reversible capacity during Na+ de/insertion. These drawbacks cause poor rate capability and fast capacity decay in most P2‐type layered oxides. To address these challenges, a novel high sodium content (0.85) and plateau‐free P2‐type cathode‐Na0.85Li0.12Ni0.22Mn0.66O2 (P2‐NLNMO) was developed. The complete solid‐solution reaction over a wide voltage range ensures both fast Na+ mobility (10−11 to 10−10 cm2 s−1) and small volume variation (1.7 %). The high sodium content P2‐NLNMO exhibits a higher reversible capacity of 123.4 mA h g−1, superior rate capability of 79.3 mA h g−1 at 20 C, and 85.4 % capacity retention after 500 cycles at 5 C. The sufficient Na and complete solid‐solution reaction are critical to realizing high‐performance P2‐type cathodes for sodium‐ion…

Abstract Designing bifunctional catalysts capable of driving the electrochemical hydrogen evolution reaction (HER) and also H2 evolution via the hydrolysis of hydrogen storage materials such as ammonia borane (AB) is of considerable practical importance for future hydrogen economies. Herein, we systematically examined the effect of tensile lattice strain in CoRu nanoalloys supported on carbon quantum dots (CoRu/CQDs) on hydrogen generation by HER and AB hydrolysis. By varying the Ru content, the lattice parameters and Ru‐induced lattice strain in the CoRu nanoalloys could be tuned. The CoRu0.5/CQDs catalyst with an ultra‐low Ru content (1.33 wt.%) exhibited excellent catalytic activity for HER (η=18 mV at 10 mA cm−2 in 1 M KOH) and extraordinary activity for the hydrolysis of AB with a turnover frequency of 3255.4 mol mol−1(Ru) min−1 or 814.7 mol mol−1(cat) min−1 at 298 K, respectively, representing one of the best activities yet reported for AB hydrolysis over a ruthenium alloy catalyst. Moreover, the CoRu0.5/CQDs catalyst displayed excellent stability during each reaction,…

Abstract Photocatalysts derived from semiconductor heterojunctions that harvest solar energy and catalyze reactions still suffer from low solar‐to‐hydrogen conversion efficiency. Now, MXene (Ti 3 C 2 T X ) nanosheets (MNs) are used to support the in situ growth of ultrathin ZnIn 2 S 4 nanosheets (UZNs), producing sandwich‐like hierarchical heterostructures (UZNs‐MNs‐UZNs) for efficient photocatalytic H 2 evolution. Opportune lateral epitaxy of UZNs on the surface of MNs improves specific surface area, pore diameter, and hydrophilicity of the resulting materials, all of which could be beneficial to the photocatalytic activity. Owing to the Schottky junction and ultrathin 2D structures of UZNs and MNs, the heterostructures could effectively suppress photoexcited electron–hole recombination and boost photoexcited charge transfer and separation. The heterostructure photocatalyst exhibits improved photocatalytic H 2 evolution performance (6.6 times higher than pristine ZnIn 2 S 4 ) and excellent stability.

Abstract Proton storage in rechargeable aqueous zinc‐ion batteries (ZIBs) is attracting extensive attention owing to the fast kinetics of H+ insertion/extraction. However, it has not been achieved in organic materials‐based ZIBs with a mild electrolyte. Now, aqueous ZIBs based on diquinoxalino [2,3‐a:2′,3′‐c] phenazine (HATN) in a mild electrolyte are developed. Electrochemical and structural analysis confirm for the first time that such Zn–HATN batteries experience a H+ uptake/removal behavior with highly reversible structural evolution of HATN. The H+ uptake/removal endows the Zn–HATN batteries with enhanced electrochemical performance. Proton insertion chemistry will broaden the horizons of aqueous Zn–organic batteries and open up new opportunities to construct high‐performance ZIBs.

Abstract Amorphous iron phosphate (FePO4) has attracted enormous attention as a promising cathode material for sodium‐ion batteries (SIBs) because of its high theoretical specific capacity and superior electrochemical reversibility. Nevertheless, the low rate performance and rapid capacity decline seriously hamper its implementation in SIBs. Herein, we demonstrate a sagacious multi‐step templating approach to skillfully craft amorphous FePO4 yolk–shell nanospheres with mesoporous nanoyolks supported inside the robust porous outer nanoshells. Their unique architecture and large surface area enable these amorphous FePO4 yolk–shell nanospheres to manifest remarkable sodium storage properties with high reversible capacity, outstanding rate performance, and ultralong cycle life.

Abstract Polymeric carbon nitride modified with selected heteroatom dopants was prepared and used as a model photocatalyst to identify and understand the key mechanisms required for efficient photoproduction of H 2 O 2 via selective oxygen reduction reaction (ORR). The photochemical production of H 2 O 2 was achieved at a millimolar level per hour under visible‐light irradiation along with 100 % apparent quantum yield (in 360–450 nm region) and 96 % selectivity in an electrochemical system (0.1 V vs. RHE). Spectroscopic analysis in spatiotemporal resolution and theoretical calculations revealed that the synergistic association of alkali and sulfur dopants in the polymeric matrix promoted the interlayer charge separation and polarization of trapped electrons for preferable oxygen capture and reduction in ORR kinetics. This work highlights the key features that are responsible for controlling the photocatalytic activity and selectivity toward the two‐electron ORR, which should be the basis of further development of solar H 2 O 2 production.

Bimetallische Spinelloxide sind effiziente Katalysatoren für die Aktivierung von Peroxymonosulfat (PMS), der katalytische Mechanismus ist jedoch unklar. Die kritische Rolle der Mn-O-Kovalenz für die intrinsische Aktivität von Co3−xMnxO4 und ein neuer Mechanismus der Co/Mn-Synergie werden von Wen-Wei Li et al. in ihrem Forschungsartikel auf S. 278 aufgezeigt. Co verstärkt die Mn-O-Kovalenz in der oktaedrischen Konfiguration von Co3−xMnxO4, was die Ladungstransferenergie der MnOh-PMS-Wechselwirkung senkt und die MnVI/MnIII-Redoxzyklen drastisch beschleunigt.

Abstract Metallic zinc is a promising anode candidate of aqueous zinc‐ion batteries owing to its high theoretical capacity and low redox potential. However, Zn anodes usually suffer from dendrite and side reactions, which will degrade their cycle stability and reversibility. Herein, we developed an in situ spontaneously reducing/assembling strategy to assemble a ultrathin and uniform MXene layer on the surface of Zn anodes. The MXene layer endows the Zn anode with a lower Zn nucleation energy barrier and a more uniformly distributed electric field through the favorable charge redistribution effect in comparison with pure Zn. Therefore, MXene‐integrated Zn anode exhibits obviously low voltage hysteresis and excellent cycling stability with dendrite‐free behaviors, ensuring the high capacity retention and low polarization potential in zinc‐ion batteries.

Abstract Metal–organic framework (MOF) glasses are promising candidates for membrane fabrication due to their significant porosity, the ease of processing, and most notably, the potential to eliminate the grain boundary that is unavoidable for polycrystalline MOF membranes. Herein, we developed a ZIF‐62 MOF glass membrane and exploited its intrinsic gas‐separation properties. The MOF glass membrane was fabricated by melt‐quenching treatment of an in situ solvothermally synthesized polycrystalline ZIF‐62 MOF membrane on a porous ceramic alumina support. The molten ZIF‐62 phase penetrated into the nanopores of the support and eliminated the formation of intercrystalline defects in the resultant glass membrane. The molecular sieving ability of the MOF membrane is remarkably enhanced via vitrification. The separation factors of the MOF glass membrane for H 2 /CH 4 , CO 2 /N 2 and CO 2 /CH 4 mixtures are 50.7, 34.5, and 36.6, respectively, far exceeding the Robeson upper bounds.

Abstract The performance of lithium-ion battery is highly dependent on its interfacial chemistry, which is regulated by electrolytes. Conventional electrolyte typically contains polar solvents to dissociate Li salts. Here, we report a novel weakly-solvating electrolyte (WSE) that consists of a pure non-polar solvent, which leads to a peculiar solvation structure where ion pairs and aggregates prevail under a low salt concentration of 1.0 M. Importantly, WSE forms unique anion-derived interphases on graphite electrodes that exhibit fast-charging and long-term cycling characteristics. First-principles calculations unravel a general principle that the competitive coordination between anions and solvents to Li ion is the origin of different interfacial chemistries. By bridging the gap between solution thermodynamics and interfacial chemistry in batteries, this work opens a brand-new way towards precise electrolyte engineering for energy storage devices with desired properties.

Abstract It is still a great challenge to achieve high selectivity of CH 4 in CO 2 electroreduction reactions (CO 2 RR) because of the similar reduction potentials of possible products and the sluggish kinetics for CO 2 activation. Stabilizing key reaction intermediates by single type of active sites supported on porous conductive material is crucial to achieve high selectivity for single product such as CH 4 . Here, Cu 2 O(111) quantum dots with an average size of 3.5 nm are in situ synthesized on a porous conductive copper‐based metal–organic framework (CuHHTP), exhibiting high selectivity of 73 % towards CH 4 with partial current density of 10.8 mA cm −2 at −1.4 V vs. RHE (reversible hydrogen electrode) in CO 2 RR. Operando infrared spectroscopy and DFT calculations reveal that the key intermediates (such as *CH 2 O and *OCH 3 ) involved in the pathway of CH 4 formation are stabilized by the single active Cu 2 O(111) and hydrogen bonding, thus generating CH 4 instead of CO.

Abstract A method is developed to fabricate tumor microenvironment (TME) stimuli‐responsive nanoplatform for fluorescence (FL) imaging and synergistic cancer therapy via assembling photosensitizer (chlorine e6, Ce6) modified carbon dots (CDs‐Ce6) and Cu2+. The as‐obtained nanoassemblies (named Cu/CC nanoparticles, NPs) exhibit quenched FL and photosensitization due to the aggregation of CDs‐Ce6. Their FL imaging and photodynamic therapy (PDT) functions are recovered efficiently once they entering tumor sites by the stimulation of TME. Introducing of Cu2+ not only provides extra chemodynamic therapy (CDT) function through reaction with hydrogen peroxide (H2O2), but also depletes GSH in tumors by a redox reaction, thus amplifying the intracellular oxidative stress and enhancing the efficacy of reactive oxygen species (ROS) based therapy. Cu/CC NPs can act as a FL imaging guided trimodal synergistic cancer treatment agent by photothermal therapy (PTT), PDT, and thermally amplified CDT.

Abstract Lead‐free halide perovskites have drawn wide attention as alternatives to their toxic and poorly stable lead‐based counterparts. Among them, double perovskites with Cs2AgInCl6 composition, often doped with various elements, have been in the spotlight owing to their intriguing optical properties, namely, self‐trapped exciton (STEs) emission and dopant‐induced photoluminescence. This interest has sparked different synthesis approaches towards both crystals and nanocrystals, and the exploration of many alloy compositions with mono‐ and trivalent cations other than Ag+ and In3+. In this Minireview we describe the recent developments on Cs2AgInCl6 bulk crystals and nanocrystals, their synthesis strategies, intrinsic optical properties, and tunable photoluminescence originating from different alloying and doping effects. We also discuss progress on computational studies aimed at understanding the thermodynamic stability, the role of defects, and the origin of photoluminescence in relation to the STEs and the direct band gap character.

Abstract In situ evolution of electrocatalysts is of paramount importance in defining catalytic reactions. Catalysts for aprotic electrochemistry such as lithium–sulfur (Li‐S) batteries are the cornerstone to enhance intrinsically sluggish reaction kinetics but the true active phases are often controversial. Herein, we reveal the electrochemical phase evolution of metal‐based pre‐catalysts (Co 4 N) in working Li‐S batteries that renders highly active electrocatalysts (CoS x ). Electrochemical cycling induces the transformation from single‐crystalline Co 4 N to polycrystalline CoS x that are rich in active sites. This transformation propels all‐phase polysulfide‐involving reactions. Consequently, Co 4 N enables stable operation of high‐rate (10 C, 16.7 mA cm −2 ) and electrolyte‐starved (4.7 μL mg S −1 ) Li‐S batteries. The general concept of electrochemically induced sulfurization is verified by thermodynamic energetics for most of low‐valence metal compounds.

Abstract Die Biokatalyse hat in verschiedenen Einsatzgebieten Anwendung als Alternative zur chemischen Katalyse gefunden, wobei die herausragendsten Beispiele die Herstellung chiraler Verbindungen für Pharmazeutika und für die Riechstoff‐ und Aromen‐Industrie sind. Zunehmend werden Biokatalysatoren im großen Maßstab genutzt, um Spezial‐ und sogar Bulkchemikalien herzustellen. Dieser Aufsatz soll lehrreiche Beispiele in diesem Gebiet mit besonderem Augenmerk auf skalierbare chemische Verfahren aufzeigen. Es werden Möglichkeiten und Grenzen enzymatischer Synthesen diskutiert, und es wird ein Ausblick auf neu aufstrebende Enzymklassen gegeben.

Abstract Aggregationsinduzierte Emissionen (AIEs) sind ein photophysikalisches Phänomen, bei dem Molekülaggregate stärkere Emissionen zeigen als die entsprechenden Einzelmoleküle. Im Laufe von nahezu 20 Jahren hat die Forschung zu AIEs große Erfolge in der Materialentwicklung, bei mechanistischen Arbeiten und bei Hochtechnologie‐Anwendungen erlebt. Diese Erfolge haben auch bewiesen, dass für molekulare Aggregate viele Eigenschaften und Funktionen beobachtet werden, die den entsprechenden molekularen Spezies fehlen. In diesem Aufsatz fassen wir die Fortschritte auf dem Gebiet der AIE und angrenzender Gebiete zusammen. Dabei konzentrieren wir uns auf die Eigenschaften neuer Materialien, die durch Aggregation jenseits der mikroskopischen molekularen Ebene entstehen. Wir hoffen, dass dieser Aufsatz weitere Forschungsarbeiten auf dem Gebiet molekularer Ensembles auf der Mesoebene und darüber hinaus inspirieren und so signifikante Fortschritte in den Material‐ und Biowissenschaften ermöglichen wird.

Abstract The reversibility of metal anode is a fundamental challenge to the lifetime of rechargeable batteries. Though being widely employed in aqueous energy storage systems, metallic zinc suffers from dendrite formation that severely hinders its applications. Here we report texturing Zn as an effective way to address the issue of zinc dendrite. An in‐plane oriented Zn texture with preferentially exposed (002) basal plane is demonstrated via a sulfonate anion‐induced electrodeposition, noting no solid report on (002) textured Zn till now. Anion‐induced reconstruction of zinc coordination is revealed to be responsible for the texture formation. Benchmarking against its (101) textured‐counterpart by the conventional sulphate‐based electrolyte, the Zn (002) texture enables highly reversible stripping/plating at a high current density of 10 mA cm −2 , showing its dendrite‐free characteristics. The Zn (002) texture‐based aqueous zinc battery exhibits excellent cycling stability. The developed anion texturing approach provides a pathway towards exploring zinc chemistry and prospering…

Abstract Membrane‐based reverse electrodialysis (RED) is considered as the most promising technique to harvest osmotic energy. However, the traditional membranes are limited by high internal resistance and low efficiency, resulting in undesirable power densities. Herein, we report the combination of oppositely charged Ti3C2Tx MXene membranes (MXMs) with confined 2D nanofluidic channels as high‐performance osmotic power generators. The negatively or positively charged 2D MXene nanochannels exhibit typical surface‐charge‐governed ion transport and show excellent cation or anion selectivity. By mixing the artificial sea water (0.5 m NaCl) and river water (0.01 m NaCl), we obtain a maximum power density of ca. 4.6 Wm−2, higher than most of the state‐of‐the‐art membrane‐based osmotic power generators, and very close to the commercialization benchmark (5 Wm−2). Through connecting ten tandem MXM‐RED stacks, the output voltage can reach up 1.66 V, which can directly power the electronic devices.

Abstract Two‐dimensional covalent organic frameworks (2D COFs), an emerging class of crystalline porous polymers, have been recognized as a new platform for efficient solar‐to‐hydrogen energy conversion owing to their pre‐designable structures and tailor‐made functions. Herein, we demonstrate that slight modulation of the chemical structure of a typical photoactive 2D COF (Py‐HTP‐BT‐COF) via chlorination (Py‐ClTP‐BT‐COF) and fluorination (Py‐FTP‐BT‐COF) can lead to dramatically enhanced photocatalytic H 2 evolution rates (HER=177.50 μmol h −1 with a high apparent quantum efficiency (AQE) of 8.45 % for Py‐ClTP‐BT‐COF). Halogen modulation at the photoactive benzothiadiazole moiety can efficiently suppress charge recombination and significantly reduce the energy barrier associated with the formation of H intermediate species (H*) on polymer surface. Our findings provide new prospects toward design and synthesis of highly active organic photocatalysts toward solar‐to‐chemical energy conversion.

Abstract Chiral quasi‐2D perovskite single crystals (SCs) were investigated for their circular polarized light (CPL) detecting capability. Quasi‐2D chiral perovskites, [(R)‐β‐MPA]2MAPb2I7 ((R)‐β‐MPA=(R)‐(+)‐β‐methylphenethylamine, MA=methylammonium), have intrinsic chirality and the capability to distinguish different polarization states of CPL photons. Corresponding quasi‐2D SCs CPL photodetector exhibit excellent detection performance. In particular, our device responsivity is almost one order of magnitude higher than the reported 2D perovskite CPL detectors to date. The crystallization dynamics of the film were modulated to facilitate its carrier transport. Parallel oriented perovskite films with a homogeneous energy landscape is crucial to maximize the carrier collection efficiency. The photodetector also exhibits superior mechanical flexibility and durability, representing a promising candidate for sensitive and robust CPL photodetectors.

Abstract The concept of aggregation‐induced emission (AIE) has opened new opportunities in many research fields. Motivated by the unique feature of AIE fluorogens (AIEgens), during the past decade, many AIE molecular probes and AIE nanoparticle (NP) probes have been developed for sensing, imaging and theranostic applications with excellent performance outperforming conventional fluorescent probes. This Review summarizes the latest advancement of AIE molecular probes and AIE NP probes and their emerging biomedical applications. Special focus is to reveal how the AIE probes are evolved with the development of new multifunctional AIEgens, and how new strategies have been developed to overcome the limitations of traditional AIE probes for more translational applications via fluorescence imaging, photoacoustic imaging and image‐guided photodynamic/photothermal therapy. The outlook discusses the challenges and future opportunities for AIEgens to advance the biomedical field.

Abstract The electrolytes in lithium metal batteries have to be compatible with both lithium metal anodes and high voltage cathodes, and can be regulated by manipulating the solvation structure. Herein, to enhance the electrolyte stability, lithium nitrate (LiNO3) and 1,1,2,2‐tetrafuoroethyl‐2′,2′,2′‐trifuoroethyl(HFE) are introduced into the high‐concentration sulfolane electrolyte to suppress Li dendrite growth and achieve a high Coulombic efficiency of >99 % for both the Li anode and LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes. Molecular dynamics simulations show that NO3− participates in the solvation sheath of lithium ions enabling more bis(trifluoromethanesulfonyl)imide anion (TFSI−) to coordinate with Li+ ions. Therefore, a robust LiNxOy−LiF‐rich solid electrolyte interface (SEI) is formed on the Li surface, suppressing Li dendrite growth. The LiNO3‐containing sulfolane electrolyte can also support the highly aggressive LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode, delivering a discharge capacity of 190.4 mAh g−1 at 0.5 C for 200 cycles with a capacity retention rate of 99.5 %.

Abstract Nickel iron oxyhydroxide is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium. Whereas the presence of Fe ions is essential to the high activity, the functions of Fe are currently under debate. Using oxygen isotope labeling and operando Raman spectroscopic experiments, we obtain turnover frequencies (TOFs) of both Ni and Fe sites for a series of Ni and NiFe layered double hydroxides (LDHs), which are structurally defined samples of the corresponding oxyhydroxides. The Fe sites have TOFs 20–200 times higher than the Ni sites such that at an Fe content of 4.7 % and above the Fe sites dominate the catalysis. Higher Fe contents lead to larger structural disorder of the NiOOH host. A volcano‐type correlation was found between the TOFs of Fe sites and the structural disorder of NiOOH. Our work elucidates the origin of the Fe‐dependent activity of NiFe LDH, and suggests structural ordering as a strategy to improve OER catalysts.

Abstract Metal–organic frameworks (MOFs) are emerging as leading candidates for nanoscale drug delivery, as a consequence of their high drug capacities, ease of functionality, and the ability to carefully engineer key physical properties. Despite many anticancer treatment regimens consisting of a cocktail of different drugs, examples of delivery of multiple drugs from one MOF are rare, potentially hampered by difficulties in postsynthetic loading of more than one cargo molecule. Herein, we report a new strategy, multivariate modulation, which allows incorporation of up to three drugs in the Zr MOF UiO‐66 by defect‐loading. The drugs are added to one‐pot solvothermal synthesis and are distributed throughout the MOF at defect sites by coordination to the metal clusters. This tight binding comes with retention of crystallinity and porosity, allowing a fourth drug to be postsynthetically loaded into the MOFs to yield nanoparticles loaded with cocktails of drugs that show enhancements in selective anticancer cytotoxicity against MCF‐7 breast cancer cells in vitro. We believe that…

Abstract Optical imaging plays a crucial role in biomedicine. However, due to strong light scattering and autofluorescence in biological tissue between 650–900 nm, conventional optical imaging often has a poor signal‐to‐background ratio and shallow penetration depth, which limits its ability in deep‐tissue in vivo imaging. Second near‐infrared fluorescence, chemiluminescence, and photoacoustic imaging modalities mitigate these issues by their respective advantages of minimized light scattering, eliminated external excitation, and ultrasound detection. To enable disease detection, activatable molecular probes (AMPs) with the ability to change their second near‐infrared fluorescence, chemiluminescence, or photoacoustic signals in response to a biomarker have been developed. This Minireview summarizes the molecular design strategies, sensing mechanisms, and imaging applications of AMPs. The potential challenges and perspectives of AMPs in deep‐tissue imaging are also discussed.

Abstract Herein, we highlight redox‐inert Zn2+ in spinel‐type oxide (ZnXNi1−XCo2O4) to synergistically optimize physical pore structure and increase the formation of active species on the catalyst surface. The presence of Zn2+ segregation has been identified experimentally and theoretically under oxygen‐evolving condition, the newly formed VZn−O−Co allows more suitable binding interaction between the active center Co and the oxygenated species, resulting in superior ORR performance. Moreover, a liquid flow Zn–air battery is constituted employing the structurally optimized Zn0.4Ni0.6Co2O4 nanoparticles supported on N‐doped carbon nanotube (ZNCO/NCNTs) as an efficient air cathode, which presents remarkable power density (109.1 mW cm−2), high open circuit potential (1.48 V vs. Zn), excellent durability, and high‐rate performance. This finding could elucidate the experimentally observed enhancement in the ORR activity of ZnXNi1−XCo2O4 oxides after the OER test.

Abstract A strategy to covalently connect crystalline covalent organic frameworks (COFs) with semiconductors to create stable organic–inorganic Z‐scheme heterojunctions for artificial photosynthesis is presented. A series of COF–semiconductor Z‐scheme photocatalysts combining water‐oxidation semiconductors (TiO2, Bi2WO6, and α‐Fe2O3) with CO2 reduction COFs (COF‐316/318) was synthesized and exhibited high photocatalytic CO2‐to‐CO conversion efficiencies (up to 69.67 μmol g−1 h−1), with H2O as the electron donor in the gas–solid CO2 reduction, without additional photosensitizers and sacrificial agents. This is the first report of covalently bonded COF/inorganic‐semiconductor systems utilizing the Z‐scheme applied for artificial photosynthesis. Experiments and calculations confirmed efficient semiconductor‐to‐COF electron transfer by covalent coupling, resulting in electron accumulation in the cyano/pyridine moieties of the COF for CO2 reduction and holes in the semiconductor for H2O oxidation, thus mimicking natural photosynthesis.

Abstract Rh is a promising electrocatalyst for the nitrogen reduction reaction (NRR) given its suitable nitrogen‐adsorption energy and low overpotential. However, the NRR pathway on Rh surfaces remains unknown. In this study, we employ surface‐enhanced infrared‐absorption spectroscopy (SEIRAS) and differential electrochemical mass spectrometry (DEMS) to study the reaction mechanism of NRR on Rh. N2Hx (0≤x≤2) is detected with a N=N stretching mode at ≈2020 cm−1 by SEIRAS and a signal at m/z=29 by DEMS. A new two‐step reaction pathway on Rh surfaces is proposed that involves an electrochemical process with a two‐electron transfer to form N2H2 and its subsequent decomposition in the electrolyte producing NH3. Our results also indicate that nitrate reduction and the NRR share the same reaction intermediate N2Hx.

Abstract Pure green emitters are essential for realizing an ultrawide color gamut in next‐generation displays. Herein, by fusing the difficult‐to‐access aza‐aromatics onto B (boron)–N (nitrogen) skeleton, a hybridized multi‐resonance and charge transfer (HMCT) molecule AZA‐BN was successfully synthesized through an effective one‐shot multiple cyclization method. AZA‐BN shows pure green fluorescence with photoluminance quantum yield of 99.7 %. The corresponding green device exhibits a maximum external quantum efficiency and power efficiency of 28.2 % and 121.7 lm W−1, respectively, with a full width half maximum (FWHM) of merely 30 nm and Commission Internationale de l'Eclairage (CIE) coordinateyof 0.69, representing the purest green bottom‐emitting organic light‐emitting diode.

Abstract Electrochemical reduction of CO2 to valuable fuels is appealing for CO2 fixation and energy storage. However, the development of electrocatalysts with high activity and selectivity in a wide potential window is challenging. Herein, atomically thin bismuthene (Bi‐ene) is pioneeringly obtained by an in situ electrochemical transformation from ultrathin bismuth‐based metal–organic layers. The few‐layer Bi‐ene, which possesses a great mass of exposed active sites with high intrinsic activity, has a high selectivity (ca. 100 %), large partial current density, and quite good stability in a potential window exceeding 0.35 V toward formate production. It even deliver current densities that exceed 300.0 mA cm−2 without compromising selectivity in a flow‐cell reactor. Using in situ ATR‐IR spectra and DFT analysis, a reaction mechanism involving HCO3− for formate generation was unveiled, which brings new fundamental understanding of CO2 reduction.

Abstract Propane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt‐based catalysts usually suffer from short‐term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand‐protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt–Zn clusters inside silicalite‐1 (S‐1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6–54 h −1 and specific activity of propylene formation of 65.5 mol g Pt −1 h −1 (WHSV=108 h −1 ) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4@S‐1‐H catalyst even after 13000 min on stream (WHSV=3.6 h −1 ), affording an extremely low deactivation constant of 0.001 h −1 , which is 200 times lower than that of the PtZn4/Al 2 O 3 counterpart under the same conditions. We also show that the introduction of Cs + ions into the zeolite can improve the regeneration stability of catalysts, and…

Abstract Recently, hydrovoltaic technology emerged as a novel renewable energy harvesting method, which dramatically extends the capability to harvest water energy. However, the urgent issue restricting its device performance is poor carrier transport properties of the solid surface if large charged interface is considered simultaneously. Herein, a hydrovoltaic device based on silicon nanowire arrays (SiNWs), which provide large charged surface/volume ratio and excellent carrier transport properties, yields sustained electricity by a carrier concentration gradient induced by evaporation‐induced water flow inside nanochannels. The device can yield direct current with a short‐circuit current density of over 55 μA cm −2 , which is three orders larger than a previously reported analogous device (approximately 40 nA cm −2 ). Moreover, it exhibits a constant output power density of over 6 μW cm −2 and an open‐circuit voltage of up to 400 mV. Our finding may pave a way for developing energy‐harvesting devices from ubiquitous evaporation‐driven internal water flow in nature with…

The field of electrochemical synthesis has developed rapidly over the last decade and has provided alternative synthetic methods with the absence of stoichiometric amounts of chemical oxidants or reductants. Although sustainable electrosynthetic procedures have been developed, relatively few examples of highly enantioselective catalytic electrosynthesis have been reported to date. The development of general strategies for electrochemical enantiocontrol has thus proven to be a considerable challenge. This Minireview highlights the current knowledge and recent advances in the synthetic utility of electrochemical transformations for asymmetric synthesis. Specifically, three major types of catalytic enantioselective strategy in electrosynthesis are outlined, including electrochemical activation of chiral catalyst-bound substrates, asymmetric cascade electrochemical processes, and chemically modified chiral electrodes.

Abstract This article offers a materials‐chemistry perspective for colloidal quantum dots (QDs) in the field of display, including QD‐enhanced liquid‐crystal‐display (QD‐LCD) and QD‐based light‐emitting‐diodes (QLEDs) display. The rapid successes of QDs for display in the past five years are not accidental but have a deep root in both maturity of their synthetic chemistry and their unique chemical, optical, and optoelectronic properties. This article intends to discuss the natural match of QD emitters for display and chemical means to eventually bring about their full potential.

Abstract An organic crystal of 4,4′‐bis(N‐carbazolyl)‐1,1′‐biphenyl (pCBP) exhibits time‐dependent afterglow color from blue to orange over 1 s. Both experimental and computational data confirm that the color evolution results from well‐separated, long‐persistent thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP) with different but comparable decay rates. TADF is enabled by a small S1–T1 energy gap of 0.7 kcal mol−1. The good separation of TADF and RTP is due to a 11.8 kcal mol−1 difference in the S0 energies of the S1 and T1 structures, indicating that apart from the excited‐state properties, tuning the ground state is also important for luminescence properties. This afterglow color evolution of pCBP allows its applications in anticounterfeiting and data encryption with high security levels.

Abstract Single‐atom catalysts have drawn great attention, especially in electrocatalysis. However, most of previous works focus on the enhanced catalytic properties via improving metal loading. Engineering morphologies of catalysts to facilitate mass transport through catalyst layers, thus increasing the utilization of each active site, is regarded as an appealing way for enhanced performance. Herein, we design an overhang‐eave structure decorated with isolated single‐atom iron sites via a silica‐mediated MOF‐templated approach for oxygen reduction reaction (ORR) catalysis. This catalyst demonstrates superior ORR performance in both alkaline and acidic electrolytes, comparable to the state‐of‐the‐art Pt/C catalyst and superior to most precious‐metal‐free catalysts reported to date. This activity originates from its edge‐rich structure, having more three‐phase boundaries with enhanced mass transport of reactants to accessible single‐atom iron sites (increasing the utilization of active sites), which verifies the practicability of such a synthetic approach.

Abstract 3D‐MoS2can adsorb organic molecules and provide multidimensional electron transport pathways, implying a potential application for environment remediation. Here, we study the degradation of aromatic organics in advanced oxidation processes (AOPs) by a 3D‐MoS2sponge loaded with MoS2nanospheres and graphene oxide (GO). Exposed Mo4+active sites on 3D‐MoS2can significantly improve the concentration and stability of Fe2+in AOPs and keep the Fe3+/Fe2+in a stable dynamic cycle, thus effectively promoting the activation of H2O2/peroxymonosulfate (PMS). The degradation rate of organic pollutants in the 3D‐MoS2system is about 50 times higher than without cocatalyst. After a 140 L pilot‐scale experiment, it still maintains high efficiency and stable AOPs activity. After 16 days of continuous reaction, the 3D‐MoS2achieves a degradation rate of 120 mg L−1antibiotic wastewater up to 97.87 %. The operating cost of treating a ton of wastewater is only US$ 0.33, suggesting huge industrial applications.

Abstract Atomic co‐catalysts offer high potential to improve the photocatalytic performance, of which the preparation with earth‐abundant elements is challenging. Here, a new molten salt method (MSM) is designed to prepare atomic Ni co‐catalyst on widely studied TiO 2 nanoparticles. The liquid environment and space confinement effect of the molten salt leads to atomic dispersion of Ni ions on TiO 2 , while the strong polarizing force provided by the molten salt promotes formation of strong Ni−O bonds. Interestingly, Ni atoms are found to facilitate the formation of oxygen vacancies (OV) on TiO 2 during the MSM process, which benefits the charge transfer and hydrogen evolution reaction. The synergy of atomic Ni co‐catalyst and OV results in 4‐time increase in H 2 evolution rate compared to that of the Ni co‐catalyst on TiO 2 prepared by an impregnation method. This work provides a new strategy of controlling atomic co‐catalyst together with defects for efficient photocatalytic water splitting.

Abstract Two‐dimensional conductive metal–organic frameworks (2D c‐MOFs) as an emerging class of multifunctional materials have attracted extensive attention due to their predictable and diverse structures, intrinsic permanent porosity, high charge mobility, and excellent electrical conductivity. Such unique characteristics render them as a promising new platform for electrical related devices. This Minireview highlights the recent key progress of 2D c‐MOFs with emphasis on the design strategies, unique electrical properties, and potential applications in electrochemical energy storage. The thorough elucidation of structure–function correlations may offer a guidance for the development of 2D c‐MOFs based next‐generation energy storage devices.

Abstract Single atom catalysts (SACs) with the maximized metal atom efficiency have sparked great attention. However, it is challenging to obtain SACs with high metal loading, high catalytic activity, and good stability. Herein, we demonstrate a new strategy to develop a highly active and stable Ag single atom in carbon nitride (Ag‐N2C2/CN) catalyst with a unique coordination. The Ag atomic dispersion and Ag‐N2C2 configuration have been identified by aberration‐correction high‐angle‐annular‐dark‐field scanning transmission electron microscopy (AC‐HAADF‐STEM) and extended X‐ray absorption. Experiments and DFT calculations further verify that Ag‐N2C2 can reduce the H2 evolution barrier, expand the light absorption range, and improve the charge transfer of CN. As a result, the Ag‐N2C2/CN catalyst exhibits much better H2 evolution activity than the N‐coordinated Ag single atom in CN (Ag‐N4/CN), and is even superior to the Pt nanoparticle‐loaded CN (PtNP/CN). This work provides a new idea for the design and synthesis of SACs with novel configurations and excellent catalytic activity and…

Abstract Transformation of carbon dioxide to high value‐added chemicals becomes a significant challenge for clean energy studies. Here a stable and conductive covalent organic framework was developed for electrocatalytic carbon dioxide reduction to carbon monoxide in aqueous solution. The cobalt(II) phthalocyanine catalysts are topologically connected via robust phenazine linkage into a two‐dimensional tetragonal framework that is stable under boiling water, acid, or base conditions. The 2D lattice enables full π conjugation along x and y directions as well as π conduction along the z axis across the π columns. With these structural features, the electrocatalytic framework exhibits a faradaic efficiency of 96 %, an exceptional turnover number up to 320 000, and a long‐term turnover frequency of 11 412 hour−1, which is a 32‐fold improvement over molecular catalyst. The combination of catalytic activity, selectivity, efficiency, and durability is desirable for clean energy production.

Abstract The high reactive oxygen species (ROS) generation ability and simple construction of sonosensitizer systems remain challenging in sonodynamic therapy against the hypoxic tumor. In this work, we rationally prepared MOF‐derived double‐layer hollow manganese silicate nanoparticle (DHMS) with highly effective ROS yield under ultrasound irradiation for multimodal imaging‐guided sonodynamic therapy (SDT). The presence of Mn in DHMS increased ROS generation efficiency because it could be oxidized by holes to improve the electron–hole separation. Moreover, DHMS could produce oxygen in the tumor microenvironment, which helps overcome the hypoxia of the solid tumor and thus enhance the treatment efficiency. In vivo experiments demonstrated efficient tumor inhibition in DHMS‐mediated SDT guided by ultrasound and magnetic resonance imaging. This work presents a MOF‐derived nanoparticle with sonosensitive and oxygen generating ability, which provides a promising strategy for tumor hypoxia in SDT.

Abstract Perovskite lattice distortion induced by residual tensile strain from the thermal expansion mismatch between the electron‐transporting layer (ETL) and perovskite film causes a sluggish charge extraction and transfer dynamics in all‐inorganic CsPbBr 3 perovskite solar cells (PSCs) because of their higher crystallization temperatures and thermal expansion coefficients. Herein, the interfacial strain is released by fabricating a WS 2 /CsPbBr 3 van der Waals heterostructure owing to their matched crystal lattice structure and the atomically smooth dangling bond‐free surface to act as a lubricant between ETL and CsPbBr 3 perovskite. Arising from the strain‐released interface and condensed perovskite lattice, the best device achieves an efficiency of 10.65 % with an ultrahigh open‐circuit voltage of 1.70 V and significantly improved stability under persistent light irradiation and humidity (80 %) attack over 120 days.

Abstract Electrochemical N 2 reduction reactions (NRR) and the N 2 oxidation reaction (NOR), using H 2 O and N 2 , are a sustainable approach to N 2 fixation. To date, owing to the chemical inertness of nitrogen, emerging electrocatalysts for the electrochemical NRR and NOR at room temperature and atmospheric pressure remain largely underexplored. Herein, a new‐type Fe‐SnO 2 was designed as a Janus electrocatalyst for achieving highly efficient NRR and NOR catalysis. A high NH 3 yield of 82.7 μg h −1 mg cat. −1 and a Faraday efficiency (FE) of 20.4 % were obtained for NRR. This catalyst can also serve as an excellent NOR electrocatalyst with a NO 3 − yields of 42.9 μg h −1 mg cat. −1 and a FE of 0.84 %. By means of experiments and DFT calculations, it is revealed that the oxygen vacancy‐anchored single‐atom Fe can effectively adsorb and activate chemical inert N 2 molecules, lowering the energy barrier for the vital breakage of N≡N and resulting in the enhanced N 2 fixation performance.

Abstract Sodium borohydride (NaBH4) is among the most studied hydrogen storage materials because it is able to deliver high‐purity H2 at room temperature with controllable kinetics via hydrolysis; however, its regeneration from the hydrolytic product has been challenging. Now, a facile method is reported to regenerate NaBH4 with high yield and low costs. The hydrolytic product NaBO2 in aqueous solution reacts with CO2, forming Na2B4O7⋅10 H2O and Na2CO3, both of which are ball‐milled with Mg under ambient conditions to form NaBH4 in high yield (close to 80 %). Compared with previous studies, this approach avoids expensive reducing agents such as MgH2, bypasses the energy‐intensive dehydration procedure to remove water from Na2B4O7⋅10 H2O, and does not require high‐pressure H2 gas, therefore leading to much reduced costs. This method is expected to effectively close the loop of NaBH4 regeneration and hydrolysis, enabling a wide deployment of NaBH4 for hydrogen storage.

Abstract It is important to develop self‐producing reactive oxygen species (ROSs) systems and maintain the continuous and effective degradation of organic pollutants. Herein, for the first time, a system of ultrasound‐treated CoS2−x mixed with Fe2+ is constructed to sustainably release singlet oxygen (1O2) for the effective degradation of various organic pollutants, including dyes, phenols, and antibiotics. Ultrasonic treatment produces defects on the surface of CoS2 which promote the production of ROSs and the circulation of Fe3+/Fe2+. With the help of Co4+/Co3+ exposed on the surface of CoS2−x, the directional conversion of superoxide radical (.O2−) to 1O2 is realized. The CoS2−x/Fe2+ system can degrade organic pollutants efficiently for up to 30 days, which is significantly better than the currently recognized CuPx system (<3 days). Therefore, CoS2−x provides a new choice for the long‐term remediation of organic pollutants in controlling large area river pollution.

Abstract MOFs have a highly ordered self‐assembled nanostructure, high surface area, nanoporosity with tunable size and shape, reliable host–guest interactions, and responsiveness to physical and chemical stimuli which can be exploited to address critical issues in sensor applications. On the one hand, the nanoscale pore size of MOFs ranging from less than 1 nm to ≈ 10 nm not only allows the diffusion of small molecules into the pores or through the MOF layer, but also excludes other larger molecules depending on the size, shape, and conformation of MOFs. On the other hand, MOFs with flexible structure exhibit a dynamic response to external stimuli, including guest molecules, temperature, pressure, pH, and light. Due to the unsaturated coordination metal sites and active functional groups, the interaction between certain analytes and active sites results in high selectivity. In this review, we summarize the latest studies on MOF‐based electronic sensors in terms of the function of MOFs, discuss challenges, and suggest perspectives.

Abstract Carbon dioxide (CO2) conversion is promising in alleviating the excessive CO2 level and simultaneously producing valuables. This work reports the preparation of carbon nanorods encapsulated bismuth oxides for the efficient CO2 electroconversion toward formate production. This resultant catalyst exhibits a small onset potential of −0.28 V vs. RHE and partial current density of over 200 mA cm−2 with a stable and high Faradaic efficiency of 93 % for formate generation in a flow cell configuration. Electrochemical results demonstrate the synergistic effect in the Bi2O3@C promotes the rapid and selective CO2 reduction in which the Bi2O3 is beneficial for improving the reaction kinetics and formate selectivity, while the carbon matrix would be helpful for enhancing the activity and current density of formate production. This work provides effective bismuth‐based MOF derivatives for efficient formate production and offers insights in promoting practical CO2 conversion technology.

Abstract Supramolecular polymers that can heal themselves automatically usually exhibit weakness in mechanical toughness and stretchability. Here we exploit a toughening strategy for a dynamic dry supramolecular network by introducing ionic cluster‐enhanced iron‐carboxylate complexes. The resulting dry supramolecular network simultaneous exhibits tough mechanical strength, high stretchability, self‐healing ability, and processability at room temperature. The excellent performance of these distinct supramolecular polymers is attributed to the hierarchical existence of four types of dynamic combinations in the high‐density dry network, including dynamic covalent disulfide bonds, noncovalent H‐bonds, iron‐carboxylate complexes and ionic clustering interactions. The extremely facile preparation method of this self‐healing polymer offers prospects for high‐performance low‐cost material among others for coatings and wearable devices.

Abstract Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. Herein, a semiconducting covalent organic framework (named NDA‐TN‐AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA‐TN‐AO with a high anti‐biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV, thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA‐TN‐AO to uranium in seawater reaches 6.07 mg g−1, which is 1.33 times of that in dark. The NDA‐TN‐AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.

Abstract Modern chemistry seems to be unlimited in molecular size and elemental composition. Metal‐organic frameworks or biological macromolecules involve complex architectures and a large variety of elements. Yet, a general and broadly applicable theoretical method to describe the structures and interactions of molecules beyond the 1000‐atom size regime semi‐quantitatively is not self‐evident. For this purpose, a generic force field named GFN‐FF is presented, which is completely newly developed to enable fast structure optimizations and molecular‐dynamics simulations for basically any chemical structure consisting of elements up to radon. The freely available computer program requires only starting coordinates and elemental composition as input from which, fully automatically, all potential‐energy terms are constructed. GFN‐FF outperforms other force fields in terms of generality and accuracy, approaching the performance of much more elaborate quantum‐mechanical methods in many cases.

Abstract Visible‐light‐responsive hierarchical Co9S8/ZnIn2S4 tubular heterostructures are fabricated by growing 2D ZnIn2S4 nanosheets on 1D hollow Co9S8 nanotubes. This design combines two photoresponsive sulfide semiconductors in a stable heterojunction with a hierarchical hollow tubular structure, improving visible‐light absorption, yielding a large surface area, exposing sufficient catalytically active sites, and promoting the separation and migration of photogenerated charges. The hierarchical nanotubes exhibit excellent photocatalytic H2 evolution and CrVI reduction efficiency. Under visible‐light illumination, the optimized Co9S8/ZnIn2S4 heterostructure provides a remarkable H2 generation rate of 9039 μmol h−1 g−1 without the use of any co‐catalysts and CrVI is completely reduced in 45 min. The Co9S8/ZnIn2S4 heterostructure is stable after multiple photocatalytic cycles.

Abstract Carbazole‐based DABNA analogues (CzDABNAs) were synthesized from triarylamine by regioselective one‐shot single and double borylation. The reaction proceeded selectively at the ortho position of the carbazolyl group, where the highest occupied molecular orbital is mainly localized owing to the difference in the electron‐donating abilities of the diarylamino and carbazolyl groups. The facile and scalable method enabled synthesis of CzDABNAs, exhibiting narrowband thermally activated delayed fluorescence with emission spectra ranging from deep blue to green. The organic light‐emitting diode devices employing these products as emitters exhibited deep‐blue, sky‐blue, and green emission with high external quantum efficiencies of 19.5, 21.8, and 26.7 %, respectively.

Abstract Currently, photosensitizers (PSs) that are microenvironment responsive and hypoxia active are scarcely available and urgently desired for antitumor photodynamic therapy (PDT). Presented herein is the design of a redox stimuli activatable metal‐free photosensitizer (aPS), also functioning as a pre‐photosensitizer as it is converted to a PS by the mutual presence of glutathione (GSH) and hydrogen peroxide (H2O2) with high specificity on a basis of domino reactions on the benzothiadiazole ring. Superior to traditional PSs, the activated aPS contributed to efficient generation of reactive oxygen species including singlet oxygen and superoxide ion through both type 1 and type 2 pathways, alleviating the aerobic requirement for PDT. Equipped with a triphenylphosphine ligand for mitochondria targeting, mitoaPS showed excellent phototoxicity to tumor cells with low light fluence under both normoxic and hypoxic conditions, after activation by intracellular GSH and H2O2. The mitoaPS was also compatible to near infrared PDT with two photon excitation (800 nm) for extensive…

Abstract Das Vergrößern des Recyclingstroms erfordert einen neuen Ansatz, der über das Schmelzen und Umformen hinausgeht. Es gibt einige Techniken des chemischen Recyclings mit dem Potential, bestehende Recyclingmöglichkeiten zu ergänzen. In diesem Aufsatz sind die Methoden des chemischen Recyclings dargestellt und anhand einer Ökobilanz bewertet, ergänzt durch eine Aufzählung von Prozessen und Firmen in diesem Bereich. Wir zeigen, dass bestimmte Techniken besonders für spezifische Müllströme geeignet sind und dass nur eine Kombination aus den vorhandenen Methoden geeignet ist, das Kunststoffmüllproblem zu lösen. Aktuelle Forschung sollte realistischeren und weniger reinen Mischströmen größere Aufmerksamkeit widmen, während Trenn‐ und Sortierprozesse z. B. durch effektivere Regularien verbessert werden müssen. Dieser Aufsatz soll zur Entwicklung von Verfahren inspirieren, mit denen hochwertige Produkte hergestellt werden können, die die Kreislaufwirtschaft antreiben, indem sie nötige Wirtschaftsanreize und Erleichterungen für die Umwelt bieten.

Abstract Surface atomic arrangement and coordination of photocatalysts highly exposed to different crystal facets significantly affect the photoreactivity. However, controversies on the true photoreactivity of a specific facet in heterogeneous photocatalysis still exits. Herein, we exemplified well‐defined BiOBr nanosheets dominating with respective facets, (001) and (010), to track the reactivity of crystal facets for photocatalytic water splitting. The real photoreactivity of BiOBr‐(001) were evidenced to be significantly higher than BiOBr‐(010) for both hydrogen production and oxygen evolution reactions. Further in situ photochemical probing studies verified the distinct reactivity is not only owing to the highly exposed facets, but dominated by the co‐exposing facets, leading to an efficient spatial separation of photogenerated charges and further making the oxidation and reduction reactions separately occur with different reaction rates, which ordains the fate of the true photoreactivity.

Abstract Zero‐dimensional (0D) lead‐free perovskites have unique structures and optoelectronic properties. Undoped and Sb‐doped all inorganic, lead‐free, 0D perovskite single crystals A2InCl5(H2O) (A=Rb, Cs) are presented that exhibit greatly enhanced yellow emission. To study the effect of coordination H2O, Sb‐doped A3InCl6 (A=Rb, Cs) are also synthesized and further studied. The photoluminescence (PL) color changes from yellow to green emission. Interestingly, the photoluminescence quantum yield (PLQY) realizes a great boost from <2 % to 85–95 % through doping Sb3+. We further explore the effect of Sb3+ dopants and the origin of bright emission by ultrafast transient absorption techniques. Furthermore, Sb‐doped 0D rubidium indium chloride perovskites show excellent stability. These findings not only provide a way to design a set of new high‐performance 0D lead‐free perovskites, but also reveal the relationship between structure and PL properties.

Abstract Aqueous batteries using inorganic compounds as electrode materials are considered a promising solution for grid‐scale energy storage, while wide application is limited by the short life and/or high cost of electrodes. Organics with carbonyl groups are being investigated as the alternative to inorganic electrode materials because they offer the advantages of tunable structures, renewability, and they are environmentally benign. Furthermore, the wide internal space of such organic materials enables flexible storage of various charged ions (for example, H + , Li + , Na + , K + , Zn 2+ , Mg 2+ , and Ca 2+ , and so on). We offer a comprehensive overview of the progress of organics containing carbonyls for energy storage and conversion in aqueous electrolytes, including applications in aqueous batteries as solid‐state electrodes, in flow batteries as soluble redox species, and in water electrolysis as redox buffer electrodes. The advantages of organic electrodes are summarized, with a discussion of the challenges remaining for their practical application.

Abstract The most pressing challenges for light‐driven hydrogel actuators include reliance on UV light, slow response, poor mechanical properties, and limited functionalities. Now, a supramolecular design strategy is used to address these issues. Key is the use of a benzylimine‐functionalized anthracene group, which red‐shifts the absorption into the visible region and also stabilizes the supramolecular network through π–π interactions. Acid–ether hydrogen bonds are incorporated for energy dissipation under mechanical deformation and maintaining hydrophilicity of the network. This double‐crosslinked supramolecular hydrogel developed via a simple synthesis exhibits a unique combination of high strength, rapid self‐healing, and fast visible‐light‐driven shape morphing both in the wet and dry state. As all of the interactions are dynamic, the design enables the structures to be recycled and reprogrammed into different 3D objects.

Abstract The emerging metal single‐atom catalyst has aroused extensive attention in multiple fields, such as clean energy, environmental protection, and biomedicine. Unfortunately, though it has been shown to be highly active, the origins of the activity of the single‐atom sites remain unrevealed to date owing to the lack of deep insight on electronic level. Now, partially oxidized Ni single‐atom sites were constructed in polymeric carbon nitride (CN), which elevates the photocatalytic performance by over 30‐fold. The 3d orbital of the partially oxidized Ni single‐atom sites is filled with unpaired d‐electrons, which are ready to be excited under irradiation. Such an electron configuration results in elevated light response, conductivity, charge separation, and mobility of the photocatalyst concurrently, thus largely augmenting the photocatalytic performance.

Abstract Electrochemical water splitting for H2 production is limited by the sluggish anode oxygen evolution reaction (OER), thus using hydrazine oxidation reaction (HzOR) to replace OER has received great attention. Here we report the hierarchical porous nanosheet arrays with abundant Ni3N‐Co3N heterointerfaces on Ni foam with superior hydrogen evolution reaction (HER) and HzOR activity, realizing working potentials of −43 and −88 mV for 10 mA cm−2, respectively, and achieving an industry‐level 1000 mA cm−2 at 200 mV for HzOR. The two‐electrode overall hydrazine splitting (OHzS) electrolyzer requires the cell voltages of 0.071 and 0.76 V for 10 and 400 mA cm−2, respectively. The H2 production powered by a direct hydrazine fuel cell (DHzFC) and a commercial solar cell are investigated to inspire future practical applications. DFT calculations decipher that heterointerfaces simultaneously optimize the hydrogen adsorption free energy (ΔGH*) and promote the hydrazine dehydrogenation kinetics. This work provides a rationale for advanced bifunctional electrocatalysts, and propels the…

Abstract The upgrading of plastic waste is one of the grand challenges for the 21st century owing to its disruptive impact on the environment. Here, we show the first example of the upgrading of various aromatic plastic wastes with C−O and/or C−C linkages to arenes (75–85 % yield) via catalytic hydrogenolysis over a Ru/Nb2O5 catalyst. This catalyst not only allows the selective conversion of single‐component aromatic plastic, and more importantly, enables the simultaneous conversion of a mixture of aromatic plastic to arenes. The excellent performance is attributed to unique features including: (1) the small sized Ru clusters on Nb2O5, which prevent the adsorption of aromatic ring and its hydrogenation; (2) the strong oxygen affinity of NbOx species for C−O bond activation and Brønsted acid sites for C−C bond activation. This study offers a catalytic path to integrate aromatic plastic waste back into the supply chain of plastic production under the context of circular economy.

Abstract The design and synthesis of organic materials with a narrow emission band in the longer wavelength region beyond 510 nm remain a great challenge. For constructing narrowband green emitters, we propose a unique molecular design strategy based on frontier molecular orbital engineering (FMOE), which can integrate the advantages of a twisted donor–acceptor (D‐A) structure and a multiple resonance (MR) delayed fluorescence skeleton. Attaching an auxiliary donor to a MR skeleton leads to a novel molecule with twisted D‐A and MR structure characteristics. Importantly, a remarkable red‐shift of the emission maximum and a narrowband spectrum are achieved simultaneously. The target molecule has been employed as an emitter to fabricate green organic light‐emitting diodes (OLEDs) with Commission Internationale de L'Eclairage (CIE) coordinates of (0.23, 0.69) and a maximum external quantum efficiency (EQE) of 27.0 %.

Abstract Increasing long‐term photostability of BiVO4 photoelectrode is an important issue for solar water splitting. The NiOOH oxygen evolution catalyst (OEC) has fast water oxidation kinetics compared to the FeOOH OEC. However, it generally shows a lower photoresponse and poor stability because of the more substantial interface recombination at the NiOOH/BiVO4 junction. Herein, we utilize a plasma etching approach to reduce both interface/surface recombination at NiOOH/BiVO4 and NiOOH/electrolyte junctions. Further, adding Fe2+ into the borate buffer electrolyte alleviates the active but unstable character of etched‐NiOOH/BiVO4, leading to an outstanding oxygen evolution over 200 h. The improved charge transfer and photostability can be attributed to the active defects and a mixture of NiOOH/NiO/Ni in OEC induced by plasma etching. Metallic Ni acts as the ion source for the in situ generation of the NiFe OEC over long‐term durability.

Abstract Methods to synthesize crystalline covalent triazine frameworks (CTFs) are limited and little attention has been paid to development of hydrophilic CTFs and photocatalytic overall water splitting. A route to synthesize crystalline and hydrophilic CTF‐HUST‐A1 with a benzylamine‐functionalized monomer is presented. The base reagent used plays an important role in the enhancement of crystallinity and hydrophilicity. CTF‐HUST‐A1 exhibits good crystallinity, excellent hydrophilicity, and excellent photocatalytic activity in sacrificial photocatalytic hydrogen evolution (hydrogen evolution rate up to 9200 μmol g−1 h−1). Photocatalytic overall water splitting is achieved by depositing dual co‐catalysts in CTF‐HUST‐A1, with H2 evolution and O2 evolution rates of 25.4 μmol g−1 h−1 and 12.9 μmol g−1 h−1 in pure water without using sacrificial agent.

Abstract Proteins are responsible for the occurrence and treatment of many diseases, and therefore protein sequencing will revolutionize proteomics and clinical diagnostics. Biological nanopore approach has proved successful for single‐molecule DNA sequencing, which resolves the identities of 4 natural deoxyribonucleotides based on the current blockages and duration times of their translocations across the nanopore confinement. However, open challenges still remain for biological nanopores to sequentially identify each amino acid (AA) of single proteins due to the inherent complexity of 20 proteinogenic AAs in charges, volumes, hydrophobicity and structures. Herein, we focus on recent exciting advances in biological nanopores for single‐molecule protein sequencing (SMPS) from native protein unfolding, control of peptide translocation, AA identification to applications in disease detection.

Abstract Environmentally friendly halide double perovskites with improved stability are regarded as a promising alternative to lead halide perovskites. The benchmark double perovskite, Cs2AgBiBr6, shows attractive optical and electronic features, making it promising for high‐efficiency optoelectronic devices. However, the large band gap limits its further applications, especially for photovoltaics. Herein, we develop a novel crystal‐engineering strategy to significantly decrease the band gap by approximately 0.26 eV, reaching the smallest reported band gap of 1.72 eV for Cs2AgBiBr6 under ambient conditions. The band‐gap narrowing is confirmed by both absorption and photoluminescence measurements. Our first‐principles calculations indicate that enhanced Ag–Bi disorder has a large impact on the band structure and decreases the band gap, providing a possible explanation of the observed band‐gap narrowing effect. This work provides new insights for achieving lead‐free double perovskites with suitable band gaps for optoelectronic applications.

Abstract Near‐infrared (NIR) activatable fluorescent probes have been considered to be the effective edge tools for the investigation of cell biology and disease diagnosis because of their outstanding advantages. Related genes involved in tumor genesis and progression regulate the overexpression of certain enzymes. Owing to the distinctive characteristics of quick reaction time and favorable pharmacokinetics, enzyme‐reactive NIR optical probes have shown great potential in the diagnosis of tumorigenesis and in image‐guided intraoperative surgeries with high signal‐to‐noise ratios. In this review, we mainly summarize the latest advancements in enzyme‐reactive NIR fluorescent probes from design strategy to biomedical application. Specifically, some challenges and prospects in this field are presented at the end of the review, which will be beneficial to innovatively construct new multifunctional fluorescent probes and actively promote their clinical transformation in the future.

Abstract Current plasmonic photocatalysts are mainly based on noble metal nanoparticles and rarely work in the infrared (IR) light range. Herein, cost‐effective Bi2O3−x with oxygen vacancies was formed in situ on commercial bismuth powder by calcination at 453.15 K in atmosphere. Interestingly, defects introduced into Bi2O3−x simultaneously induced a localized surface plasmon resonance (LSPR) in the wavelength range of 600–1400 nm and enhanced the adsorption for CO2 molecules, which enabled efficient photocatalysis of CO2‐to‐CO (ca. 100 % selectivity) even under low‐intensity near‐IR light irradiation. Significantly, the apparent quantum yield for CO evolution at 940 nm reached 0.113 %, which is approximately 4 times that found at 450 nm. We also showed that the unique LSPR allows for the realization of a nearly linear dependence of photocatalytic CO production rate on light intensity and operating temperature. Finally, based on an IR spectroscopy study, an oxygen‐vacancy induced Mars‐van Krevlen mechanism was proposed to understand the CO2 reduction reactions.

Incorporation of a non-hexagonal ring into a nanographene framework can lead to new electronic properties. During the attempted synthesis of naphthalene-bridged double [6]helicene and heptagon-containing nanographene by the Scholl reaction, an unexpected azulene-embedded nanographene and its triflyloxylated product were obtained, as confirmed by X-ray crystallographic analysis and 2D NMR spectroscopy. A 5/7/7/5 ring-fused substructure containing two formal azulene units is formed, but only one of them shows an azulene-like electronic structure. The formation of this unique structure is explained by arenium ion mediated 1,2-phenyl migration and a naphthalene to azulene rearrangement reaction according to an in-silico study. This report represents the first experimental example of the thermodynamically unfavorable naphthalene to azulene rearrangement and may lead to new azulene-based molecular materials.

Abstract The polarity of a semiconducting molecule affects its intrinsic photophysical properties, which can be tuned by varying the molecular geometry. Herein, we developed aD3h‐symmetric tricyanomesitylene as a new monomer which could be reticulated into a vinylene‐linked covalent organic framework (g‐C54N6‐COF) via Knoevenagel condensation with anotherD3h‐symmetric monomer 2,4,6‐tris(4′‐formyl‐biphenyl‐4‐yl)‐1,3,5‐triazine. Replacing tricyanomesitylene with aC2v‐symmetric 3,5‐dicyano‐2,4,6‐trimethylpyridine gave a less‐symmetric vinylene‐linked COF (g‐C52N6‐COF). The octupolar conjugated characters of g‐C54N6‐COF were reflected in its scarce solvatochromic effects either in ground or excited states, and endowed it with more promising semiconducting behavior as compared with g‐C52N6‐COF, such as enhanced light‐harvesting and excellent photo‐induced charge generation and separation. Along with the matched energy level, g‐C54N6‐COF enabled the two‐half reactions of photocatalytic water splitting with an average O2evolution rate of 51.0 μmol h−1 g−1and H2evolution rate of 2518.9 μmol…

Abstract NH 4 + ions as charge carriers show potential for aqueous rechargeable batteries. Studied here for the first time is the NH 4 + ‐storage chemistry using electrodeposited manganese oxide (MnO x ). MnO x experiences morphology and phase transformations during charge/discharge in dilute ammonium acetate (NH 4 Ac) electrolyte. The NH 4 Ac concentration plays an important role in NH 4 + storage for MnO x . The transformed MnO x with a layered structure delivers a high specific capacity (176 mAh g −1 ) at a current density of 0.5 A g −1 , and exhibits good cycling stability over 10 000 cycles in 0.5 M NH 4 Ac, outperforming the state‐of‐the‐art NH 4 + hosting materials. Experimental results suggest a solid‐solution behavior associated with NH 4 + migration in layered MnO x . Spectroscopy studies and theoretical calculations show that the reversible NH 4 + insertion/deinsertion is accompanied by hydrogen‐bond formation/breaking between NH 4 + and the MnO x layers. These findings provide a new prototype (i.e., layered MnO x ) for NH 4 + ‐based energy storage and contributes to the…

Abstract The choice of electrode material is critical for achieving optimal yields and selectivity in synthetic organic electrochemistry. The material imparts significant influence on the kinetics and thermodynamics of electron transfer, and frequently defines the success or failure of a transformation. Electrode processes are complex and so the choice of a material is often empirical and the underlying mechanisms and rationale for success are unknown. In this review, we aim to highlight recent instances of electrode choice where rationale is offered, which should aid future reaction development.

Abstract Poor solubility often leads to low drug efficacy. Encapsulation of water‐insoluble drugs in polymeric nanoparticles offers a solution. However, low drug loading remains a critical challenge. Now, a simple and robust sequential nanoprecipitation technology is used to produce stable drug‐core polymer‐shell nanoparticles with high drug loading (up to 58.5 %) from a wide range of polymers and drugs. This technology is based on tuning the precipitation time of drugs and polymers using a solvent system comprising multiple organic solvents, which allows the formation of drug nanoparticles first followed by immediate precipitation of one or two polymers. This technology offers a new strategy to manufacture polymeric nanoparticles with high drug loading having good long‐term stability and programmed release and opens a unique opportunity for drug delivery applications.

Abstract The design of synthetic routes by retrosynthetic logic is decisively influenced by the transformations available. Transition‐metal‐catalyzed C−H activation has emerged as a powerful strategy for C−C bond formation, with myriad methods developed for diverse substrates and coupling partners. However, its uptake in total synthesis has been tepid, partially due to their apparent synthetic intractability, as well as a lack of comprehensive guidelines for implementation. This Review addresses these issues and offers a guide to identify retrosynthetic opportunities to generate C−C bonds by C−H activation processes. By comparing total syntheses accomplished using traditional approaches and recent C−H activation methods, this Review demonstrates how C−H activation enabled C−C bond construction has led to more efficient retrosynthetic strategies, as well as the execution of previously unattainable tactical maneuvers. Finally, shortcomings of existing processes are highlighted; this Review illustrates how some highlighted total syntheses can be further economized by adopting…

Abstract Developing high capacity and stable cathodes is a key to successful commercialization of aqueous Zn‐ion batteries (ZIBs). Pure layered V 2 O 5 has a high theoretical capacity (585 mAh g −1 ), but it suffers severe capacity decay. Pre‐inserting cations into V 2 O 5 can substantially stabilize the performance, but at an expense of lowered capacity. Here we show that an atomic layer deposition derived V 2 O 5 can be an excellent ZIB cathode with high capacity and exceptional cycle stability at once. We report a rapid in situ on‐site transformation of V 2 O 5 atomic layers into Zn 3 V 2 O 7 (OH) 2 ⋅2 H 2 O (ZVO) nanoflake clusters, also a known Zn‐ion and proton intercalatable material. High concentration of reactive sites, strong bonding to the conductive substrate, nanosized thickness and binder‐free composition facilitate ionic transport and promote the best utilization of the active material. We also provide new insights into the V 2 O 5 ‐dissolution mechanisms for different Zn‐salt aqueous electrolytes and their implications to the cycle stability.

Abstract Fluorescence imaging in the second near‐infrared (NIR‐II) window facilitated by aggregation‐induced emission luminogens (AIEgens) is an emerging research field. NIR‐II AIEgens overcome limitations imposed by penetration depth and fluorescence efficiency, offering high‐performance imaging with enhanced precision. Some reported NIR‐II AIEgens demonstrate capabilities for fluorescence and photoacoustic bimodal imaging, and fluorescence imaging guided photothermal therapy, which not only improves diagnosis accuracy but provides an efficient theranostic platform to accelerate preclinical translation as well. This minireview summarizes recent efforts on exploiting NIR‐II AIEgens with regard to molecular design strategies and bioapplications, and puts forward current challenges and promising prospects. This timely sketch should benefit the further exploitation of diverse and multifunctional NIR‐II AIEgens for a wide array of applications.

Abstract Bifunctional hydrogen electrocatalysis (hydrogen‐oxidation and hydrogen‐evolution reactions) in alkaline solution is desirable but challenging. Among all available electrocatalysts, Ni‐based materials are the only non‐precious‐metal‐based candidates for alkaline hydrogen oxidation, but they generally suffer from low activity. Here, we demonstrate that properly alloying Ni with Mo could significantly promote its electrocatalytic performance. Ni 4 Mo alloy nanoparticles are prepared from the reduction of molybdate‐intercalated Ni(OH) 2 nanosheets. The final product exhibits an apparent hydrogen‐oxidation activity exceeding that of the Pt benchmark and a record‐high mass‐specific kinetic current of 79 A g −1 at an overpotential of 50 mV. A superior hydrogen‐evolution performance is also measured in alkaline solution. These experimental data are rationalized by our theoretical simulations, which show that alloying Ni with Mo significantly weakens its hydrogen adsorption, improves the hydroxyl adsorption and decreases the reaction barrier for water formation.

Abstract Zinc ion hybrid capacitors (ZIHCs) are promising energy storage devices for emerging flexible electronics, but they still suffer from trade‐off in energy density and cycling life. Herein, we show that such a dilemma can be well‐addressed by deploying ZnCl2 based electrolytes. Combining experimental studies and density functional theory (DFT) calculations, for the first time, we demonstrate an intriguing chloride ion (Cl−) facilitated desolvation mechanism in hydrated [ZnCl]+(H2O)n−1 (with n=1–6) clusters. Based on this mechanism, a water‐in‐salt type hydrogel electrolyte filled with ZnCl2 was developed to concurrently improve the energy storage capacity of porous carbon materials and the reversibility of Zn metal electrode. The resulting ZIHCs deliver a battery‐level energy density up to 217 Wh kg−1 at a power density of 450 W kg−1, an unprecedented cycling life of 100 000 cycles, together with excellent low‐temperature adaptability and mechanical flexibility.

Abstract Rolf Huisgen hat vor 60 Jahren das Konzept der 1,3‐dipolaren Cycloaddition vorgestellt und dabei bis dahin unbekannte reaktive Zwischenstufen, wie z. B. Azomethinylide, in die organische Chemie eingeführt. Danach entwickelten sich die (3+2)‐Cycloadditionen von 1,3‐Dipolen an Mehrfachbindungssysteme (Huisgen‐Reaktion) zu einer der vielseitigsten Synthesemethoden in der Heterocyclenchemie. In diesem Aufsatz gehen wir auf die geschichtliche Entwicklung dieses Arbeitsgebietes ein, führen die relevanten Vorläuferarbeiten auf und schildern das Entstehen des Konzeptes und seine Weiterentwicklung. Die wichtigsten mechanistischen und präparativen Befunde werden diskutiert. Quantenmechanische Berechnungen stützen den von R. Huisgen immer favorisierten konzertierten Reaktionsmechanismus, aber in Extremfällen können auch Zwischenstufen durchlaufen werden. Die Bedeutung der 1,3‐dipolaren Cycloaddition für das Click‐Chemie‐Konzept von K. B. Sharpless wird ebenfalls diskutiert.

Abstract Light‐molecule strong coupling has emerged within the last decade as a new method to control chemical reactions. A few years ago it was discovered that chemical reactivity could be altered by vibrational strong coupling (VSC). Only a limited number of reactions have been investigated under VSC to date, including solvolysis and deprotection reactions. Here the effect of VSC on a series of aldehydes and ketones undergoing Prins cyclization, an important synthetic step in pharmaceutical chemistry, is investigated. A decrease of the second‐order rate constant with VSC of the reactant carbonyl stretching groups is observed. We also observe an increased activation energy due to VSC, but proportional changes in activation enthalpy and entropy, suggesting no substantive change in reaction pathway. The addition of common cycloaddition reactions to the stable of VSC‐modified chemical reactions is another step towards establishing VSC as a genuine tool for synthetic chemistry.

Abstract LiCoO 2 is used as a cathode material for lithium‐ion batteries, however, cationic/anodic‐redox‐induced unstable phase transitions, oxygen escape, and side reactions with electrolytes always occur when charging LiCoO 2 to voltages higher than 4.35 V, resulting in severe capacity fade. Reported here is Mg‐pillared LiCoO 2 . Dopant Mg ions, serving as pillars in the Li‐slab of LiCoO 2 , prevent slab sliding in a delithiated state, thereby suppressing unfavorable phase transitions. Moreover, the resulting Li‐Mg mixing structure at the surface of Mg‐pillared LiCoO 2 is beneficial for eliminating the cathode‐electrolyte interphase overgrowth and phase transformation in the close‐to‐surface region. Mg‐pillared LiCoO 2 exhibits a high capacity of 204 mAh g −1 at 0.2 C and an enhanced capacity retention of 84 % at 1.0 C over 100 cycles within the voltage window of 3.0–4.6 V. In contrast, pristine LiCoO 2 has a capacity retention of 14 % within the same voltage window.

Abstract The direct electrochemical conversion of carbon dioxide (CO 2 ) into multi‐carbon (C 2+ ) products still faces fundamental and technological challenges. While facet‐controlled and oxide‐derived Cu materials have been touted as promising catalysts, their stability has remained problematic and poorly understood. Herein we uncover changes in the chemical and morphological state of supported and unsupported Cu 2 O nanocubes during operation in low‐current H‐Cells and in high‐current gas diffusion electrodes (GDEs) using neutral pH buffer conditions. While unsupported nanocubes achieved a sustained C 2+ Faradaic efficiency of around 60 % for 40 h, the dispersion on a carbon support sharply shifted the selectivity pattern towards C 1 products. Operando XAS and time‐resolved electron microscopy revealed the degradation of the cubic shape and, in the presence of a carbon support, the formation of small Cu‐seeds during the surprisingly slow reduction of bulk Cu 2 O. The initially (100)‐rich facet structure has presumably no controlling role on the catalytic selectivity, whereas the…

Abstract Single‐atom catalysts are promising platforms for heterogeneous catalysis, especially for clean energy conversion, storage, and utilization. Although great efforts have been made to examine the bonding and oxidation state of single‐atom catalysts before and/or after catalytic reactions, when information about dynamic evolution is not sufficient, the underlying mechanisms are often overlooked. Herein, we report the direct observation of the charge transfer and bond evolution of a single‐atom Pt/C3N4 catalyst in photocatalytic water splitting by synchronous illumination X‐ray photoelectron spectroscopy. Specifically, under light excitation, we observed Pt−N bond cleavage to form a Pt0 species and the corresponding C=N bond reconstruction; these features could not be detected on the metallic platinum‐decorated C3N4 catalyst. As expected, H2 production activity (14.7 mmol h−1 g−1) was enhanced significantly with the single‐atom Pt/C3N4 catalyst as compared to metallic Pt‐C3N4 (0.74 mmol h−1 g−1).

Abstract Mn and Na additives have been widely studied to improve the efficiency of CO 2 hydrogenation to valuable olefins on Fe catalysts, but their effects on the catalytic properties and mechanism are still under vigorous debate. This study shows that Fe‐based catalysts with moderate Mn and Na contents are highly selective for CO 2 hydrogenation to olefins, together with low selectivities for both CO and CH 4 and much improved space‐time olefin yields compared to state‐of‐the‐art catalysts. Combined kinetic assessment and quasi in situ characterizations further unveil that the sole presence of Mn suppresses the activity of Fe catalysts because of the close contact between Fe and Mn, whereas the introduction of Na mediates the Fe–Mn interaction and provides strong basic sites. This subtle synergy between Na and Mn sheds light on the importance of the interplay of multiple additives that could bring an enabling strategy to improve catalytic activity and selectivity.

Abstract While many approaches to predict aqueous p K a values exist, the fast and accurate prediction of non‐aqueous p K a values is still challenging. Based on the iBonD experimental p K a database (39 solvents), a holistic p K a prediction model was established using machine learning. Structural and physical‐organic‐parameter‐based descriptors (SPOC) were introduced to represent the electronic and structural features of the molecules. The models trained with a neural network or the XGBoost algorithm showed the best prediction performance with a low MAE value of 0.87 p K a units. The approach allows a comprehensive mapping of all possible p K a correlations between different solvents and it was validated by predicting the aqueous p K a and micro‐p K a of pharmaceutical molecules and p K a values of organocatalysts in DMSO and MeCN with high accuracy. An online prediction platform was constructed based on the current model, which can provide p K a prediction for different types of X−H acidity in the most commonly used solvents.

Abstract The reversible capacity of AlCl4− intercalation/de‐intercalation in conventional cathodes of aluminum‐ion batteries (AIBs) is difficult to improve due to the large size of AlCl4− anions. Therefore, it is highly desirable to realize the intercalation/de‐intercalation of smaller Al‐based ions. Here, we fabricated polyaniline/single‐walled carbon nanotubes (PANI/SWCNTs) composite films and protonated the PANI nanorods. The protonation endows PANI with more active sites and enhanced conductivity. Hyper self‐protonated PANI (PANI(H+)) exhibits reversible AlCl2+ intercalation/de‐intercalation during the discharge/charge process. As a result, the discharge capacity of the Al/PANI(H+) battery is twice as high as that of the initial composite films. PANI(H+)@SWCNT electrodes also have a stable cycling life with only 0.003 % capacity decay per cycle over 8000 cycles. Owing to the excellent mechanical properties, PANI(H+)@SWCNT composite films can act as the electrodes of flexible AIBs.

Abstract Flexible zinc–air batteries (ZAB) are a promising battery candidate for emerging flexible electronic devices, but the catalysis‐based working principle and unique semi‐opened structure pose a severe challenge to their overall performance at cold temperature. Herein, we report the first flexible rechargeable ZAB with excellent low‐temperature adaptability, based on the innovation of an efficient electrocatalyst to offset the electrochemical performance shrinkage caused by decreased temperature and a highly conductive hydrogel with a polarized terminal group to render the anti‐freezing property. The fabricated ZABs show excellent electrochemical performances that outperform those of many aqueous ZABs at room temperature. They also deliver a high capacity of 691 mAh g−1 and an energy density of 798 Wh kg−1 at −20 °C (92.7 % and 87.2 % retention of the room temperature counterparts, respectively), together with excellent flexibility and reverting capability.

Abstract Aqueous zinc (Zn) batteries (AZBs) are widely considered as a promising candidate for next‐generation energy storage owing to their excellent safety features. However, the application of a Zn anode is hindered by severe dendrite formation and side reactions. Herein, an interfacial bridged organic–inorganic hybrid protection layer (Nafion‐Zn‐X) is developed by complexing inorganic Zn‐X zeolite nanoparticles with Nafion, which shifts ion transport from channel transport in Nafion to a hopping mechanism in the organic–inorganic interface. This unique organic–inorganic structure is found to effectively suppress dendrite growth and side reactions of the Zn anode. Consequently, the Zn@Nafion‐Zn‐X composite anode delivers high coulombic efficiency (ca. 97 %), deep Zn plating/stripping (10 mAh cm−2), and long cycle life (over 10 000 cycles). By tackling the intrinsic chemical/electrochemical issues, the proposed strategy provides a versatile remedy for the limited cycle life of the Zn anode.

Abstract Aggregation‐induced emission (AIE) provides an efficient strategy to synthesize highly luminescent metal nanoclusters (NCs), however, rational control of emission energy and intensity of metal NCs is still challenging. This communication reveals the impact of surface AuI‐thiolate motifs on the AIE properties of Au NCs, by employing a series of water‐soluble glutathione (GSH)‐coordinated Au complexes and NCs as a model ([Au10SR10], [Au15SR13], [Au18SR14], and [Au25SR18]−, SR=thiolate ligand). Spectroscopic investigations show that the emission wavelength of Au NCs is adjustable from visible to the near‐infrared II (NIR‐II) region by controlling the length of the AuI‐SR motifs on the NC surface. Decreasing the length of AuI‐SR motifs also changes the origin of cluster luminescence from AIE‐type phosphorescence to Au0‐core‐dictated fluorescence. This effect becomes more prominent when the degree of aggregation of Au NCs increases in solution.

Abstract The electrochemical reduction of N 2 to NH 3 is emerging as a promising alternative for sustainable and distributed production of NH 3 . However, the development has been impeded by difficulties in N 2 adsorption, protonation of *NN, and inhibition of competing hydrogen evolution. To address the issues, we design a catalyst with diatomic Pd‐Cu sites on N‐doped carbon by modulation of single‐atom Pd sites with Cu. The introduction of Cu not only shifts the partial density of states of Pd toward the Fermi level but also promotes the d‐2π* coupling between Pd and adsorbed N 2 , leading to enhanced chemisorption and activated protonation of N 2 , and suppressed hydrogen evolution. As a result, the catalyst achieves a high Faradaic efficiency of 24.8±0.8 % and a desirable NH 3 yield rate of 69.2±2.5 μg h −1 mg cat. −1 , far outperforming the individual single‐atom Pd catalyst. This work paves a pathway of engineering single‐atom‐based electrocatalysts for enhanced ammonia electrosynthesis.

Abstract Metal‐organic frameworks (MOFs) have been shown to be an excellent platform in photocatalysis. However, to suppress electron–hole recombination, a Pt cocatalyst is usually inevitable, especially in photocatalytic H2 production, which greatly limits practical application. Herein, for the first time, monodisperse, small‐size, and noble‐metal‐free transitional‐metal phosphides (TMPs; for example, Ni2P, Ni12P5), are incorporated into a representative MOF, UiO‐66‐NH2, for photocatalytic H2 production. Compared with the parent MOF and their physical mixture, both TMPs@MOF composites display significantly improved H2 production rates. Thermodynamic and kinetic studies reveal that TMPs, behaving similar ability to Pt, greatly accelerate the linker‐to‐cluster charge transfer, promote charge separation, and reduce the activation energy of H2 production. Significantly, the results indicate that Pt is thermodynamically favorable, yet Ni2P is kinetically preferred for H2 production, accounting for the higher activity of Ni2P@UiO‐66‐NH2 than Pt@UiO‐66‐NH2.

cycles are established as a potentially general paradigm in photoredox Ni-catalyzed carbon-heteroatom cross-coupling reactions through a strategy that allows us to recapitulate photoredox-like reactivity in the absence of light across a wide range of substrates in the amination, etherification, and esterification of aryl bromides, the latter of which has remained, hitherto, elusive under thermal Ni catalysis. Moreover, the accessibility of esterification in the absence of light is especially notable because previous mechanistic studies on this transformation under photoredox conditions have unanimously invoked energy-transfer-mediated pathways.