The 100 most-cited articles in ACS Applied Materials & Interfaces, 2022

Engineered wound dressing materials with excellent injectability, self-healing ability, tissue-adhesiveness, especially the ones possessing potential therapeutic effects have great practical significance in healthcare. Herein, an injectable quaternary ammonium chitosan (QCS)/tannic acid (TA) hydrogel based on QCS and TA was designed and fabricated by facile mixing of the two ingredients under physiological conditions. In this system, hydrogels were mainly cross-linked by dynamic ionic bonds and hydrogen bonds between QCS and TA, which endows the hydrogel with excellent injectable, self-healing, and adhesive properties. Benefitting from the inherent antioxidative, antibacterial, and hemostatic abilities of TA and QCS, this hydrogel showed superior reactive oxygen species scavenging activity, broad-spectrum antibacterial ability, as well as rapid hemostatic capability. Moreover, the QCS/TA 2.5 hydrogel (containing 2.5% TA) exhibited excellent biocompatibility. The in vivo experiments also showed that QCS/TA 2.5 hydrogel dressing not only rapidly stopped the bleeding of arterial and…

Bacterial infections are a common problem associated with wound treatment that imposes a significant burden on healthcare systems and patients. As a result, healthcare providers urgently need new treatment strategies to protect people. Hydrogel biomaterials with inherent antimicrobial properties offer an attractive and viable solution to this issue. Here, for the first time, we have developed a new efficient synthetic strategy to prepare cationic hydrogels (PHCI) with intrinsically efficient antimicrobial properties by chemically cross-linking trans -1,4-cyclohexanediamine with 1,3-dibromo-2-propanol using a condensation reaction without the use of toxic cross-linking agents. As expected, the prepared PHCI hydrogel possessed an inherent antibacterial ability that can adsorb and kill Staphylococcus aureus and Escherichia coli electrostatically. Notably, in vivo experiments on normal and diabetic rat models confirmed that the PHCI hydrogel can quickly stop bleeding, efficiently kill bacteria, promote the conversion of macrophages from the proinflammatory M1 phenotype to the repaired…

The development of materials with outstanding performance for sensitive and selective detection of multiple analytes is essential for the development of human health and society. Luminescent metal-organic frameworks (LMOFs) have controllable surface and pore sizes and excellent optical properties. Therefore, a variety of LMOF-based sensors with diverse detection functions can be easily designed and applied. Furthermore, the introduction of energy transfer (ET) into LMOFs (ET-LMOFs) could provide a richer design concept and a much more sensitive and accurate sensing performance. In this review, we focus on the recent five years of advances in ET-LMOF-based sensing materials, with an emphasis on photochemical and photophysical mechanisms. We discuss in detail possible energy transfer processes within a MOF structure or between MOFs and guest materials. Finally, the possible sensing applications of the ET-LMOF-based sensors are highlighted.

Phosphor-containing white light-emitting diodes (LEDs) with low color-correlated temperatures (CCTs) and high color rendering indexes (CRIs) are highly desirable for energy-efficient and environmentally friendly solid-state light sources. Here, we report a new and efficient blue light-excited, green-emitting Ce 3+ -activated CaY 2 ZrScAl 3 O 12 phosphor, which underpins the fabrication of high-color quality and full-visible-spectrum warm-white LED devices with ultrahigh CRI values (Ra > 96 and R9 > 96). A family of CaY 2 ZrScAl 3 O 12:Ce 3+ phosphors with different Ce 3+ dopant concentrations were prepared by high-temperature solid-state synthesis. X-ray diffraction and corresponding Rietveld refinement reveal a garnet structure with an Ia 3̅ d space group and crystallographic parameters a = b = c = 12.39645(8) Å, α = β = γ = 90°, and V = 1904.99(4) Å 3 . Luminescence properties were studied in detail as a function of Ce 3+ with the optimal concentration 1% mol. Impressively, CaY 2 ZrScAl 3 O 12:1%Ce 3+ exhibits a broad excitation band from 370 to 500 nm, peaking at ∼421 nm, which…

Tough, biocompatible, and conductive hydrogel-based strain sensors are attractive in the fields of human motion detection and wearable electronics, whereas it is still a great challenge to simultaneously integrate underwater adhesion and self-healing properties into one hydrogel sensor. Here, a highly stretchable, sensitive, and multifunctional polysaccharide-based dual-network hydrogel sensor was constructed using dialdehyde carboxymethyl cellulose (DCMC), chitosan (CS), poly(acrylic acid) (PAA), and aluminum ions (Al 3+ ). The obtained DCMC/CS/PAA (DCP) composite hydrogels exhibit robust mechanical strength and good adhesive and self-healing properties, due to the reversible dynamic chemical bonds and physical interactions such as Schiff base bonds and metal coordination. The conductivity of hydrogel is 2.6 S/m, and the sensitivity (gauge factor (GF)) is up to 15.56. Notably, the DCP hydrogel shows excellent underwater repeatable adhesion to animal tissues and good self-healing properties in water (self-healing rate > 90%, self-healing time < 10 min). The DCP hydrogel strain…

Antioxidant hydrogel has exhibited great potential for diabetic wound treatment. However, it is still a difficult challenge to realize reactive oxygen species (ROS) scavenging in an intelligent manner. Herein, we designed a novel glucose-responsive antioxidant hybrid hydrogel for enhanced diabetic wound repair. In this study, phenylboronic acid (PBA) with unique glucose-sensitivity was modified onto a hyaluronic acid (HA) chain by one-step synthesis, which was then incorporated into a polyethylene glycol diacrylates (PEG-DA) hydrogel matrix to obtain a novel hybrid hydrogel (PEG-DA/HA-PBA). Then, myricetin (MY) molecules with strong antioxidant activity were immobilized into the hybrid hydrogel by the formation of a dynamic borate bond between the polyphenol group of MY and the phenylboronic acid group of HA-PBA. The PEG-DA/HA-PBA/MY (PHM) hybrid hydrogel achieved glucose-triggered MY release, efficient ROS-scavenging (>80.0%), and also reshaped the hostile oxidative wound microenvironment (reduced MDA activity and increased SOD and GSH/GSSG levels). Furthermore, in vitro and in…

The universal application of wearable strain sensors in various situations for human-activity monitoring is considerably limited by the contradiction between high sensitivity and broad working range. There still remains a huge challenge to design sensors featuring simultaneous broad working range and high sensitivity. Herein, a typical bilayer-conductive structure Ti 3 C 2 T x MXene/carbon nanotubes (CNTs)/thermoplastic polyurethane (TPU) composite film was developed by a simple and scalable vacuum filtration process utilizing a porous electrospun thermoplastic polyurethane (TPU) mat as a skeleton. The MXene/CNTs/TPU strain sensor is composed of two parts: a brittle densely stacked MXene upper lamella and a flexible MXene/CNT-decorated fibrous network lower layer. Benefiting from the synergetic effect of the two parts along with hydrogen-bonding interactions between the porous TPU fiber mat and MXene sheets, the MXene/CNTs/TPU strain sensor possesses both a broad working range (up to 330%) and high sensitivity (maximum gauge factor of 2911) as well as superb long-term durability…

Carbon dots (CDs) were synthesized with the facile hydrothermal method to produce CDs/polyvinyl alcohol (PVA) active food packaging films. The CDs had a diameter ranging from 2.01 to 5.61 nm and were well-dispersed. The effects of different concentrations of CDs on mechanical strength, water resistance, morphology, optical, and thermal performance of the CDs/PVA films were discussed. The incorporation of CDs in the PVA film improved its mechanical properties, water resistance properties, UV blocking properties, and thermal stability and endowed the composite film with antioxidant and antimicrobial properties. The maximum scavenging rates of 2,2-diphenyl-1-picrylhydrazyl and ABTS free radicals by the 0.50% CDs/PVA film were 72.81 and 97.08%, respectively. The inhibition zone diameters of the 0.50% CDs/PVA solution against Staphylococcus aureus ( S. aureus ), Bacillus subtilis ( B. subtilis ), and Escherichia coli ( E. coli ) were 9.52, 8.21, and 9.05 mm, respectively. Using the 0.50% CDs/PVA film as active packaging, the shelf life of banana, jujube, and fried meatballs was observed…

Flexible wearable devices have achieved remarkable applications in health monitoring because of the advantages of multisignal collecting and real-time wireless transmission of information. However, the integration of bulky sensing elements and rigid metal circuit components in traditional wearable devices may lead to a mechanical and signal-conducting mismatch between wearable devices and biological tissues, thus restricting their wide applications in the human body. The excellent mechanical properties, conductivity, and high tissue resemblance of conductive hydrogel contribute to its application in flexible electronic sensors to monitor human health. In this work, a dual-network, temperature-responsive ionic conductive hydrogel with excellent stretchability, fast temperature responsiveness, and good conductivity was developed by introducing a polyvinylpyrrolidone (PVP)/ tannic acid (TA)/ Fe 3+ cross-linked network into the N, N -methylene diacrylamide (MBAA) cross-linked poly( N -isopropylacrylamide- co -acrylamide) (P(NIPAAm- co -AM)) network. Furthermore, the introduction of the…

High Resolution Image Download MS PowerPoint Slide Heterostructures of TiO 2 @Fe 2 O 3 with a specific electronic structure and morphology enable us to control the interfacial charge transport necessary for their efficient photocatalytic performance. In spite of the extensive research, there still remains a profound ambiguity as far as the band alignment at the interface of TiO 2 @Fe 2 O 3 is concerned. In this work, the extended type I heterojunction between anatase TiO 2 nanocrystals and α-Fe 2 O 3 hematite nanograins is proposed. Experimental evidence supporting this conclusion is based on direct measurements such as optical spectroscopy, X-ray photoemission spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), and the results of indirect studies of photocatalytic decomposition of rhodamine B (RhB) with selected scavengers of various active species of OH •, h •, e –, and • O 2 – . The presence of small 6–8 nm Fe 2 O 3 crystallites at the surface of TiO 2 has been confirmed in HRTEM images. Irregular 15–50 nm needle-like hematite…

gas monitoring in industrial and environmental applications.

Bacterial infection has been a considerable obstacle for diabetic wound healing. A multifunctional nanoplatform used as nanozyme for bacterial infected diabetic wound is extremely attractive. Therefore, gold nanoclusters modified zirconium-based porphyrin metal–organic frameworks (Au NCs@PCN) were constructed by an in situ growth method. Through SEM, TEM, and EDS mapping, the surface of ellipsoid-shaped particles around 190 nm was observed to be evenly interspersed with 5–8 nm gold nanoclusters. Notably, Au NCs@PCN exhibits excellent performance in exciting ROS generation and photothermal effects. Under near-infrared (NIR) laser irradiation, Au NCs@PCN can be heated to 56.2 °C and produce ROS, showing an effective killing effect on bacteria. Antibacterial studies showed that Au NCs@PCN inhibited MRSA and Amp r E. coli by destroying membrane structure and inducing protein leakage up to 95.3% and 90.6%, respectively. Animal experiments showed that Au NCs@PCN treated diabetic rats had reduced wound coverage to 2.7% within 21 days. The immunoblot analysis showed that proangiogenic and…

Diabetic foot ulcer is a serious complication in diabetes patients, imposing a serious physical and economic burden to patients and to the healthcare system as a whole. Oxidative stress is thought to be a key driver of the pathogenesis of such ulcers. However, no antioxidant drugs have received clinical approval to date, underscoring the need for the further development of such medications. Hydrogels can be applied directly to the wound site, wherein they function to prevent infection and maintain local moisture concentrations, in addition to serving as a reservoir for the delivery of a range of therapeutic compounds with the potential to expedite wound healing in a synergistic manner. Herein, we synthesized Prussian blue nanoparticles (PBNPs) capable of efficiently scavenging reactive oxygen species (ROS) owing to their ability to mimic the activity of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD). In the context of in vitro oxidative stress, these PBNPs were able to protect against cytotoxicity, protect mitochondria from oxidative stress-related damage, and…

During the long process of wound defect repair, the bioelectric stimulation around the wound gradually decreases, which can cause gradual down-regulation of the wound healing cascade response, disordered deposition of collagen fibers, and abnormal remodeling of the extracellular matrix (ECM). All these combined will eventually result in delayed wound healing and scar tissue formation. To resolve these issues, a novel ZnO nanoparticles modified PVDF/sodium alginate (SA) piezoelectric hydrogel scaffold (ZPFSA) is prepared by 3D printing technology. The prepared ZPFSA scaffold has dual piezoelectric response models, mainly consisting of vertical swelling and horizontal friction, which can be used to simulate and amplify endogenous bioelectricity to promote wound healing and prevent scar formation. Compared with other composite scaffolds, ZPFSA 0.5 (contain 0.5% ZnO nanoparticles) exhibits good biocompatibility, excellent antimicrobial properties, and stable piezoelectric response, so that it can significantly accelerate the wound healing and effectively prevent the scar tissue…

A self-healing coating possesses a broad application prospect in the metal corrosion protection area due to its pleasurable performance. By far, despite a great deal of research studies that have been reported in this field, it is still a challenge to construct an intrinsic self-healing surface that can repair a damaged structure and restore superhydrophobicity simultaneously. Herein, a self-healing superhydrophobic coating was fabricated by combining polydopamine (PDA)-functionalized Cu 2+ -doped graphene oxide (GO), octadecylamine (ODA), and polydimethylsiloxane (PDMS), which can recover the superhydrophobicity and microstructure of the coating after chemical/physical damage. The as-prepared self-healing coating displayed excellent liquid repellency with a water contact angle of 158.2 ± 2° and a sliding angle of 4 ± 1°, which endowed the Mg alloy with excellent anticorrosion performance. Once the coating is scratched, the local damaged structure will be automatically repaired through the chelation of catechol and Cu 2+ . Also, the superhydrophobicity of the coating can be rapidly…

High Resolution Image Download MS PowerPoint Slide Hydrogen peroxide (H 2 O 2 ) is a common chemical used in many industries and can be found in various biological environments, water, and air. Yet, H 2 O 2 in a certain range of concentrations can be hazardous and toxic. Therefore, it is crucial to determine its concentration at different conditions for safety and diagnostic purposes. This review provides an insight about different types of sensors that have been developed for detection of H 2 O 2 . Their flexibility, stability, cost, detection limit, manufacturing, and challenges in their applications have been compared. More specifically the advantages and disadvantages of various flexible substrates that have been utilized for the design of H 2 O 2 sensors were discussed. These substrates include carbonaceous substrates (e.g., reduced graphene oxide films, carbon cloth, carbon, and graphene fibers), polymeric substrates, paper, thin glass, and silicon wafers. Many of these substrates are often decorated with nanostructures composed of Pt, Au, Ag, MnO 2, Fe 3 O 4, or a conductive…

Microwave-absorbing materials have attracted enormous attention for electromagnetic (EM) pollution. Herein, hollow beaded Fe 3 C/N-doped carbon fibers (Fe 3 C/NCFs) were synthesized through convenient electrospinning and subsequent thermal treatment. The special hollow morphology of the samples is conducive to achieve lightweight and broadband microwave absorption properties. The thermal treatment temperatures exhibit a significant impact on conductivity and EM properties. The broadest effective absorption bandwidth (EAB) is 5.28 GHz at 2.16 mm when the thermal treatment temperature is 700 °C, and the EAB can cover 13.13 GHz with a tunable absorber thickness from 1.0 to 3.5 mm when the thermal treatment temperature is 750 °C. The excellent microwave absorption properties of the samples are due to the synergistic effect of impedance matching and strong EM energy attenuation abilities. Hence, the magnetic hollow beaded Fe 3 C/NCFs are expected to be an attractive candidate material as a lightweight and efficient microwave absorber in the future.

The development of high-rate lithium-ion batteries is required for automobile applications. To this end, internal resistances must be reduced, among which Li + transfer resistance at electrode/electrolyte interfaces is known to be the largest. Hence, it is of urgent significance to understand the mechanism and kinetics of the interfacial Li + transfer. This Spotlight on Applications presents recent progress in the analysis and mechanical understanding of interfacial Li + transfer. First, we review the reported activation energies ( E a ) at various solid/liquid interfaces. On this basis, the mechanism and rate-determining step of the interfacial Li + transfer are discussed from the viewpoints of the desolvation of Li +, the nature of the solid electrolyte interphase (SEI), and the surface structural features of electrodes. After that, we introduce promising strategies to reduce the E a, highlighting some specific cases that give remarkably low E a . We also note the variations in frequency factors or pre-exponential factors ( A ) of the interfacial Li + transfer, which are primarily…

-acetylcysteine (NAC), for the treatment of AILI is available in clinics, but novel treatment strategies are still needed due to the complicated pathological changes of AILI and the side effects of NAC. Here, we found that astaxanthin (ASX) can prevent AILI through the Nrf2/HO-1 pathway. After treatment with ASX, there was a positive activation of the Nrf2/HO-1 pathway in AILI models both in vivo and in vitro accompanied by enhanced autophagy and reduced ferroptosis. In APAP-challenged L02 liver cells, ASX reduced autophagy and enhanced apoptosis of the cells. Furthermore, we developed ASX-loaded hollow mesoporous silica nanoparticles (HMSN@ASX) to improve the aqueous solubility of ASX and targeted delivery of ASX to the liver and then significantly improve the therapeutic effects. Taken together, we found that ASX can protect against AILI by activating the Nrf2/HO-1 pathway, which mainly affects oxidative stress, autophagy, and ferroptosis processes, and the HMSN@ASX nanosystem can target the liver to enhance the treatment efficiency of AILI.

The Urbach energy indicating the width of the exponentially decaying sub-bandgap absorption tail is commonly used as the indicator of electronic quality of thin-film materials used as absorbers in solar cells. Urbach energies of hybrid inorganic–organic metal halide perovskites with various anion–cation compositions are measured by photothermal deflection spectroscopy. The variation in anion–cation composition has a substantial effect on the measured Urbach energy and hence the electronic quality of the perovskite. Depending upon the compositions, the Urbach energy varies from 18 to 65 meV for perovskite films with similar bandgap energies. For most of the perovskite compositions studied here including methylammonium (MA) + formamidinium (FA)-based Pb iodides, mixed Sn + Pb narrow-bandgap perovskites with low or intermediate Sn contents, and wide-bandgap FA + Cs- and I + Br-based perovskites, the correlation between the Urbach energy of the perovskite thin film and open-circuit voltage ( V OC ) deficit for corresponding solar cells shows a direct relationship with reduction of the…

Broad-band near-infrared (NIR) phosphors are essential to assembling portable NIR light sources for applications in spectroscopy technology. However, developing inexpensive, efficient, and thermally stable broad-band NIR phosphors remains a significant challenge. In this work, a phosphate, KAlP 2 O 7, with a wide band gap and suitable electronic environment for Cr 3+ equivalent substitution was selected as the host material. The synthesized KAlP 2 O 7:Cr 3+ material exhibits a broad-band emission covering 650–1100 nm with a peak centered at 790 nm and a full width at half-maximum (fwhm) of 120 nm under 450 nm excitation. The internal quantum efficiency (IQE) was determined to be 78.9%, and the emission intensity at 423 K still maintains 77% of that at room temperature, implying the high efficiency and excellent thermal stability of this material. Finally, a NIR phosphor-converted light-emitting diode (pc-LED) device was fabricated by using the as-prepared material combined with a 450 nm blue LED chip, which presents a high NIR output power of 32.1 mW and excellent photoelectric…

The chemical and electrochemical reactions at the positive electrode-electrolyte interface in Li-ion batteries are hugely influential on cycle life and safety. Ni-rich layered transition metal oxides exhibit higher interfacial reactivity than their lower Ni-content analogues, reacting via poorly understood mechanisms. Here, we study the role of the electrolyte solvent, specifically cyclic ethylene carbonate (EC) and linear ethyl methyl carbonate (EMC), in determining the interfacial reactivity at LiNi0.33Mn0.33Co0.33O2 (NMC111) and LiNi0.8Mn0.1Co0.1O2 (NMC811). Parasitic currents are measured during high voltage holds in NMC/Li4Ti5O12 (LTO) cells, LTO avoiding parasitic currents related to anode-cathode reduction species cross-over, and are found to be higher for EC-containing vs. EC-free electrolytes with NMC811. No difference between electrolytes are observed with NMC111. On-line gas analysis reveals this to be related to lattice oxygen release, and accompanying electrolyte decomposition, which increases substantially with greater Ni content, and for EC-containing electrolytes…

The development of high-performance energy storage materials is decisive for meeting the miniaturization and integration requirements in advanced pulse power capacitors. In this study, we designed high-performance [(Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 ] (1–1.5 x ) La x TiO 3 (BNT-BT- x La) lead-free energy storage ceramics based on their phase diagram. A strategy combining phase adjustment and domain control via doping was proposed to enhance the energy storage performance. The obtained results showed that La 3+ ions doped into BNT-BT improved the crystal structure symmetry and induced a strong dielectric relaxation behavior, which destroyed the long-term ferroelectric order and effectively promoted the formation of polar nanoregions. At x = 0.12, a high recoverable energy density ( W rec ) of ∼5.93 J/cm 3 and a relatively large energy storage efficiency (η) of 77.6% were obtained under a high breakdown electric field of 440 kV/cm. By using a two-step sintering approach for the microstructural optimization, the energy storage performance was further improved, yielding much higher W rec…

Multifunctional phase change materials (PCMs) are highly desirable for the thermal management of miniaturized and integrated electronic devices. However, the development of flexible PCMs possessing heat energy storage, shape memory, and adjustable electromagnetic interference (EMI) shielding properties under complex conditions remains a challenge. Herein, the multifunctional PCM composites were prepared by encapsulating poly(ethylene glycol) (PEG) into porous MXene/silver nanowire (AgNW) hybrid sponges by vacuum impregnation. Melamine foams (MFs) were chosen as a template to coat with MXene/AgNW (MA) to construct a continuous electrical/thermal conductive network. The MF@MA/PEG composites showed a high latent heat (141.3 J/g), high dimension retention ratio (96.8%), good electrical conductivity (75.3 S/m), and largely enhanced thermal conductivity (2.6 times of MF/PEG). Moreover, by triggering the phase change of the PEG, the sponges displayed a significant photoinduced shape memory function with a high shape fixation ratio (∼100%) and recovery ratio (∼100%). Interestingly, the EMI…

Broadband shortwave infrared (SWIR) light-emitting diodes (LEDs), capable of advancing the next-generation solid-state smart invisible lighting technology, have sparked tremendous interest and will launch ground-breaking spectroscopy and instrumental applications. Nevertheless, the device performance is still suppressed by the low quantum efficiency and limited emission bandwidth of the critical phosphor layer. Herein, we report a high-performance Ni 2+ -doped garnet solid-solution broadband SWIR emitter centered at ∼1450 nm with a large full-width at half-maximum of ∼300 nm, thereby fabricating, for the first time, a directly excited Ni 2+ -doped garnet solid-solution phosphor-converted broadband SWIR LED device. A synergetic enhancement strategy, adding a fluxing agent and a charge compensator simultaneously, is proposed to deliver a more than 20-fold increase of the SWIR emission intensity and nearly 2-fold improvement of the thermal quenching behavior. The site occupation and mechanism behind the synergetic enhancement strategy are elucidated by a combination of experimental…

Electrocatalytic nitrate reduction reaction (NO 3 RR) affords a bifunctional character in the carbon-free ammonia synthesis and remission of nitrate pollution in water. Here, we fabricated the Co 3 O 4 nanosheet array with cobalt vacancies on carbon cloth (v Co -Co 3 O 4 /CC) by in situ etching aluminum-doped Co 3 O 4 /CC, which exhibits an excellent Faradaic efficiency of 97.2% and a large NH 3 yield as high as 517.5 μmol h –1 cm –2, better than the pristine Co 3 O 4 /CC. Theoretical calculative results imply that the cobalt vacancies can tune the local electronic environment around Co sites of Co 3 O 4, increasing the charge and reducing the electron cloud density of Co sites, which is thus conducive to adsorption of NO 3 – on Co sites for greatly enhanced nitrate reduction. Furthermore, the v Co -Co 3 O 4 (311) facet presents excellent NO 3 RR activity with a low energy barrier of about 0.63 eV on a potential-determining step, which is much smaller than pristine Co 3 O 4 (1.3 eV).

Recently, wearable sensors and electronic skin systems have become prevalent, which can be employed to detect the movement status and physiological signals of wearers. Here, a pressure sensor composed of mesh-like micro-convex structure polydimethylsiloxane (PDMS), MXene nanosheet/Ag nanoflower (AgNF) films, and flexible interdigital electrodes was designed by layer-by-layer (LBL) assembly. The unique microstructure of PDMS effectively increases the contact area and improves sensitivity. Moreover, AgNFs were introduced into the MXene as a “bridge,” and the synergistic effect of the two further enhanced the performance of the sensor. The pressure sensor has high sensitivity (191.3 kPa –1 ), good stability (18,000 cycles), fast response/recovery time (80 ms/90 ms), and low detection limit (8 Pa), so it can be used for all-round monitoring of the human body. Sensing arrays were integrated with a wireless transmitter as an intelligent artificial electronic skin for spatial pressure mapping and human–computer interaction sensing. Moreover, we develop a smart glove by a simple method,…

Agrochemicals, which are crucial to meet the world food qualitative and quantitative demand, are compounds used to kill pests (insects, fungi, rodents, or unwanted plants). Regrettably, there are some important issues associated with their widespread and extensive use (e.g., contamination, bioaccumulation, and development of pest resistance); thus, a reduced and more controlled use of agrochemicals and thorough detection in food, water, soil, and fields are necessary. In this regard, the development of new functional materials for the efficient application, detection, and removal of agrochemicals is a priority. Metal-organic frameworks (MOFs) with exceptional sorptive, recognition capabilities, and catalytical properties have very recently shown their potential in agriculture. This Review emphasizes the recent advances in the use of MOFs in agriculture through three main views: environmental remediation, controlled agrochemical release, and detection of agrochemicals.

Hydrogels that combine the integrated attributes of being adhesive, self-healable, deformable, and conductive show great promise for next-generation soft robotic/energy/electronic applications. Herein, we reported a dual-network polyacrylamide (PAAM)/poly(acrylic acid) (PAA)/graphene (GR)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) (MAGP) conductive hydrogel composed of dual-cross-linked PAAM and PAA as well as PEDOT:PSS and GR as a conducting component that combines these features. A wearable strain sensor is fabricated by sandwiching the MAGP hydrogels between two dielectric carbon nanotubes (CNTs)/poly(dimethylsiloxane) (PDMS) layers, which can be utilized to monitor delicate and vigorous human motion. In addition, the hydrogel-based sensor can act as a deformable triboelectric nanogenerator (D-TENG) for harvesting mechanical energy. The D-TENG demonstrates a peak output voltage and current of 141 V and 0.8 μA, respectively. The D-TENG could easily light 52 yellow-light-emitting diodes (LEDs) simultaneously and demonstrated the capability to power small…

Conductive hydrogels are emerging as an appealing material platform for flexible electronic devices owing to their attractive mechanical flexibility and conductive properties. However, the conventional water-based conductive hydrogels tend to inevitably freeze at subzero temperature and suffer from continuous water evaporation under ambient conditions, leading to a decrease in their electrical conductivities and mechanical properties. Thus, it is extremely necessary, but generally challenging, to create an antifreezing and antidehydration conductive gel for maintaining high and stable performances in terms of electrical conductivity and mechanical properties. Herein, we fabricated a cellulose nanofibril (CNF)-reinforced and highly ion-conductive organogel featuring excellent antifreezing and antidehydration performances by immersing it in the CaCl 2 /sorbitol solution for solvent displacement. The incorporation of a rigid CNF serving as a dynamic connected bridge provided a hierarchical honeycomb-like cellular structure for the obtained CS–nanocomposite (NC) organogel networks,…

Silicon/carbon (Si/C) composites have rightfully earned the attention as anode candidates for high-energy-density lithium-ion batteries (LIBs) owing to their advantageous capacity and superior cycling stability, yet their practical application remains a significant challenge. In this study, we report the large-scale synthesis of an intriguing micro/nanostructured pore-rich Si/C microsphere consisting of Si nanoparticles tightly immobilized onto a micron-sized cross-linked C matrix that is coated by a thin C layer (denoted P-Si/ [email protected] ) using a low-cost spray-drying approach and a chemical vapor deposition process with inorganic salts as pore-forming agents. The as-obtained P-Si/ [email protected] composite has high porosity that provides sufficient inner voids to alleviate the huge volume expansion of Si. The outer smooth and robust C shells strengthen the stability of the entire structure and the solid–electrolyte interphase. Si nanoparticles embedded in a microsized cross-linked C matrix show excellent electrical conductivity and superior structural stability. By…

Near-infrared (NIR) phosphors are fascinating photoluminescence materials with applications in phosphor-converted light-emitting diodes (pc-LEDs) for night vision lighting, which are still restricted by low efficiency and thermal stability in the current research stage. In this work, AScSi 2 O 6 (A = Na/Li) are chosen as hosts due to a larger band gap and a single octahedral site for Cr 3+ doping. The NIR-emitting Cr 3+ -activated AScSi 2 O 6:Cr 3+ phosphors were successfully prepared by a common high-temperature solid-state method. X-ray diffraction and Rietveld refinement confirm that the Cr 3+ prefers to enter the Sc 3+ -octahedral lattice site in the AScSi 2 O 6 structure. Under blue light excitation, AScSi 2 O 6:Cr 3+ phosphors exhibit broadband NIR emission from 700 to 1100 nm with a full width at half-maximum of ∼150 nm owing to the 4 T 2 → 4 A 2 electron transition of Cr 3+ . The photoluminescence properties were enhanced by adjusting the fluxes and sintering conditions, and highly efficient LiScSi 2 O 6:Cr 3+ NIR phosphors with external quantum efficiencies of 33.4% were…

Flexible temperature sensors with high resolution and good reliability under deformation are a major research focus for wearable electronic devices for skin temperature monitoring. In this study, a fiber-like temperature sensor is fabricated by in situ growing poly(3,4-ethylenedioxythiophene) (PEDOT) on the surface of thermoplastic polyurethane (TPU) fiber. The temperature sensor achieves a high sensitivity of 0.95%· ° C –1 with a high linearity between 20 and 40 °C. Most importantly, the sensor achieves a high temperature resolution of 0.2 °C. Due to its structure, the temperature-sensitive fiber is easily embedded into textiles. By sewing the fiber into normal textiles in an S-shape, the interference of strain can be nearly avoided, even when the textile is stretched to 140%. Also, the obtained sensors can monitor skin temperature during exercise, which demonstrates the potential of the sensor’s application in healthcare and disease diagnosis.

Natural polysaccharide (NPH)-based injectable hydrogels have shown great potential for critical-sized bone defect repair. However, their osteogenic, angiogenic, and mechanical properties are insufficient. Here, MgO nanoparticles (NPs) were incorporated into a newly synthesized water-soluble phosphocreatine-functionalized chitosan (CSMP) water solution to form an injectable hydrogel (CSMP-MgO) via supramolecular combination between phosphate groups in CSMP and magnesium in MgO NPs to circumvent these drawbacks of chitosan-based injectable hydrogels. Water-soluble chitosan deviate CSMP was first synthesized by grafting methacrylic anhydride and phosphocreatine into a chitosan chain in a one-step lyophilization process. The phosphocreatine in this hydrogel not only provides sites to combine with MgO NPs to form supramolecular binding but also serves as the reservoir to control Mg 2+ release. As a result, the lyophilized CSMP-MgO hydrogels presented a porous structure with some small holes in the pore wall, and the pore diameters ranged from 50 to 100 μm. The CSMP-MgO injectable…

The comparatively high coercive field in Hf 0.5 Zr 0.5 O 2 (HZO) and other HfO 2 -based ferroelectric thin films leads to two critical challenges for their application in embedded ferroelectric memory: high operating voltage due to a large thickness-field product and poor endurance due to the high operating field close to the breakdown field. In this study, we demonstrate that the thickness scaling of ferroelectric HZO down to 4 nm is a promising approach to overcome these challenges. As the coercive voltage scales down almost linearly with the film thickness, the operating voltage of 4 nm HZO is reduced to 0.6 V for one-shot operation and 1.2 V for stable memory operation, which is in the voltage range compatible with scaled silicon technologies. Furthermore, it is found that the breakdown field is substantially improved in thinner HZO since the breakdown mechanism is dominated by the stress voltage, not the stress field, resulting in improved cycle-to-breakdown by more than 4 orders of magnitude when thinning from 9.5 to 4 nm. We identify two concerns accompanying thickness…

High-entropy oxides (HEOs) offer unique features through a combination of incompatible metal cations to a single crystalline lattice. Owing to their special characteristics such as abundant cation compositions, high entropy stabilization, chemical and thermal stability, and lattice distortion effect, they have drawn ever-increasing attention for various applications. However, very few studies have been reported for catalytic application, and developing HEOs with large surface areas for efficient catalytic application is still in infancy. Herein, we design nanostructured HEO of (FeNiCoCrCu) 3 O 4 using metal–organic frameworks (MOFs) as sacrificial templates to achieve a large surface area, high density of exposed active sites, and more oxygen vacancies. Single-crystalline phase HEOs with surface area as large as 206 m 2 g –1 are produced and further applied as bifunctional electrocatalysts for the urea oxidation reaction (UOR) and oxygen evolution reaction (OER). Benefiting from enhanced oxygen vacancies and a large surface area with abundant exposed active sites, the optimized HEO…

Solar-driven photoreduction of CO 2 into valuable fuels offers a sustainable technology to relieve the energy crisis as well as the greenhouse effect. Yet the exploration of highly efficient, selective, stable, and environmental benign photocatalysts for CO 2 reduction remains a major issue and challenge. The interfacial engineering of heterojunction photocatalysts could be a valid approach to boost the efficiency of the catalytic process. Herein, we propose a novel covalent organic framework/metal organic framework (COF/MOF) heterojunction photocatalyst, using olefin (C═C) linked covalent organic framework (TTCOF) and NH 2 –UiO-66 (Zr) (NUZ) as representative building blocks, for enhanced CO 2 reduction to CO. The optimized TTCOF/NUZ exhibited a superior CO yield (6.56 μmol g –1 h –1 ) in gas–solid system when irradiated by visible light and only with H 2 O (g) as weak reductant, and it was 4.4 and 5 times higher than pristine TTCOF and NUZ, respectively. The photogenerated electrons transfer route was proposed to follow the typical step-scheme (S-scheme), which was affirmed by…

Wound healing greatly affects patients’ health and produces medical burden. Therefore, we developed a multifunctional electrospun nanofiber dressing, which can inhibit methicillin-resistant Staphylococcus aureus (MRSA), drain excessive biofluid to promote wound healing, and simultaneously monitor wound pH level. The polyoxometalate (α-K 6 P 2 W 18 O 62 ·14H 2 O, P 2 W 18 ) and oxacillin (OXA) are encapsulated in hydrophobic polylactide (PLA) nanofiber to synergistically inhibit MRSA. The phenol red (PSP) is encapsulated in hydrophilic polyacrylonitrile (PAN) nanofiber to sensitively indicate wound pH in situ . The PSP/PAN nanofiber is directly electrospun on the patterning OXA/P 2 W 18 /PLA nanofiber layer to form a Janus dressing. By taking advantage of the wettability difference between the two layers, the excess biofluid can be drained away from the wound. In addition, the Janus dressing exhibits good biocompatibility and accelerates wound healing via its antimicrobial activity and skin repairing function. This multifunctional Janus electrospun nanofiber dressing would be…

Magnetic micro-/nanorobots have been regarded as a promising platform for targeted drug delivery, and tremendous strategies have been developed in recent years. However, realizing precise and efficient drug delivery in vivo still remains challenging, in which the versatile integration of good biocompatibility and reconfiguration is the main obstacle for micro-/nanorobots. Herein, we proposed a novel strategy of magnetic biohybrid microrobot multimers (BMMs) based on Chlorella ( Ch .) and demonstrated their great potential for targeted drug delivery. The spherical Ch . cells around 3–5 μm were magnetized with Fe 3 O 4 to fabricate biohybrid microrobots and then loaded with doxorubicin (DOX). Using magnetic dipolar interactions, the microrobot units could reconfigure into chain-like BMMs as tiny dimers, trimers, and so forth via attraction-induced self-assembly and disassemble reversibly via repulsion. The BMMs exhibited diverse swimming modes including rolling and tumbling with high maneuverability, and the rolling dimer’s velocity could reach 107.6 μm/s (∼18 body length/s) under a…

In the present era of intelligent electronics and Internet of Things (IoT), the demand for flexible and wearable devices is very high. Here, we have developed a high-output flexible piezoelectric nanogenerator (PENG) based on electrospun poly(vinylidene fluoride) (PVDF)-barium titanate (BaTiO 3 ) (ES PVDF-BT) composite nanofibers with an enhanced electroactive phase. On addition of 10 wt % BaTiO 3 nanoparticles, the electroactive β-phase of the PVDF is found to be escalated to ∼91% as a result of the synergistic interfacial interaction between the tetragonal BaTiO 3 nanoparticles and the ferroelectric host polymer matrix on electrospinning. The fabricated PENG device delivered an open-circuit voltage of ∼50 V and short-circuit current density of ∼0.312 mA m –2 . Also, the PVDF-BT nanofiber-based PENG device showed an output power density of ∼4.07 mW m –2, which is 10 times higher than that of a pristine PVDF nanofiber-based PENG device. Furthermore, the developed PENG has been newly demonstrated for self-powered real-time vibration sensing applications such as for mapping of…

Two-dimensional (2D) bismuth oxychalcogenide (Bi 2 O 2 X, X refers to S, Se, and Te) is one type of rising semiconductor with excellent electrical transport properties, high photoresponse, and good air stability. However, the research on 2D Bi 2 O 2 S is limited. In this work, ultrathin Bi 2 O 2 S nanosheets are synthesized by a facile and eco-friendly chemical synthesis method at room temperature. The thickness and lateral sizes are 2–4 nm and 20–40 nm, respectively. The 2D ultrathin Bi 2 O 2 S nanosheets have a broad absorption spectrum from ultraviolet (UV) to near-infrared (NIR). Photoelectrochemical (PEC) photodetectors based on 2D Bi 2 O 2 S nanosheets are fabricated by a simple drop-casting method. The 2D Bi 2 O 2 S-based PEC photodetectors show excellent photodetection performance with a broad photoresponse spectrum from 365 to 850 nm, a high responsivity of 13.0 mA/W, ultrafast response times of 10/45 ms, and good long-term stability at a bias voltage of 0.6 V, which are superior to most 2D material-based PEC photodetectors. Further, the 2D Bi 2 O 2 S PEC photodetector can…

Sorption methodologies play a pivotal role in heavy metal removal to meet the global requirements for uninterrupted access to drinkable water. Standard sorption technologies lack efficiency due to weak adsorbent–metal interaction. To this end, a layered cationic framework material loaded with phosphonate was first fabricated by a facile intercalation method to capture hazardous metals from an aqueous solution. To inquire the removal mechanisms, batch experiments, detection technologies, and simulation calculations were employed to study the interactions at the interface of clay/water. Specifically, the functionalized layered double hydroxide possessed excellent chelation adsorption properties with Zn 2+ (281.36 mg/g) and Fe 3+ (206.03 mg/g), in which model fitting results revealed that the adsorption process was chemisorption and monolayer interaction. Further, the interfacial interaction between the phosphonate and clay surface was evaluated by molecular dynamics simulation, and a new concept named the interaction region indicator was used to characterize weak interaction and…

High Resolution Image Download MS PowerPoint Slide Clean water supply in off-grid locations remains a stumbling stone for socio-economic development in remote areas where solar energy is abundant. In this regard, several technologies have already introduced various solutions to the off-grid freshwater predicament; however, most of them are either costly or complex to operate. Nonetheless, photothermal membrane distillation (PMD) has emerged as a promising candidate with great potential to be autonomously driven by solar energy. Instead of using energy-intensive bulk feed heating in conventional MD systems, PMD membranes can directly harvest the incident solar light at the membrane interface as an alternative driving energy resource for the desalination process. Because of its excellent photothermal properties and stability in ionic environments, herein, Ti 3 C 2 T x MXene was coated onto commercial polytetrafluoroethylene (PTFE) membranes to allow for a self-heated PMD process. An average water vapor flux of 0.77 kg/m 2 h with an excellent temporal response under intermitting…

gases in MOFs and will significantly accelerate the assessment of separation performances of MOF membranes and MOF/polymer MMMs. These models will also be useful to direct the extensive experimental efforts and computationally demanding molecular simulations to the fabrication and analysis of membrane materials offering high performance for a target gas separation.

The conversion of diverse polymeric substrates into laser-induced graphene (LIG) has recently emerged as a single-step method for the fabrication of patterned graphene-based wearable electronics with a wide range of applications in sensing, actuation, and energy storage. Laser-induced pyrolysis technology has many advantages over traditional graphene design: eco-friendly, designable patterning, roll-to-roll production, and controllable morphology. In this work, we designed wearable and flexible graphene-based strain and pressure sensors by laminating LIG from a commercial polyimide (PI) film. The as-prepared LIG was transferred onto a thin polydimethylsiloxane (PDMS) sheet, interwoven inside an elastic cotton sports fabric with the fabric glue as a wearable sensor. The single LIG/PDMS layer acts as a strain sensor, and a two-layer perpendicular stacking of LIG/PDMS ( x and y laser-directed films) is designed for pressure sensing. This newly designed graphene textile (IGT) sensor performs four functions in volleyball sportswear, including volleyball reception detection, finger touch…

Both the low energy density of near-infrared (NIR) photothermal conversion during treatment and the recurrence and metastasis after local treatment have been the main obstacles and conundrums in polydopamine-mediated tumor photothermal therapy (PTT). Herein, On the basis of the enhancement of NIR absorption by ligand to metal charge transfer (LMCT) in transition-metal complexes and the activation of antitumor immunity by an appropriate concentration of Fe(III) ions, Fe(III)-chelated PDA nanoparticles (Fe-PDA NPs) with high loading and responsive release of iron ions were synthesized through a prechelation–polymerization method. First, Fe(III) chelated with the catechol groups in DA to form a mono-dopa-Fe(III) chelate, and then the polymerization of dopamine was initiated under alkaline conditions. The results revealed that the mono-dopa-Fe(III) chelate was still the main form of the Fe ion existing in Fe-PDA and was able to greatly enhance the light absorption behaviors of PDA in NIR, resulting a superior photothermal conversion ability (η = 55.5%). Moreover, the existence of…

Electrochemical nitrate reduction reaction (NO 3 RR) offers a new pathway for low-temperature green ammonia synthesis. It is widely known that copper and its copper oxide catalysts are selective for NO 3 RRs, although the role played by their oxidation state in catalysis is not fully understood. Here, we found that in situ electrochemical reduction modulates the oxidation state of copper facilitating in situ loading of Cu 2 O active sites on island-like copper, and investigated the effect of cuprous oxide on nitrate reduction. We found that the improvement of ammonia yield (Faraday efficiency: 98.28%, selectivity: 96.6%) was closely related to the generation of Cu 2 O, which exceeded the performance of the state-of-the-art catalysts available today. The presence of a multilayer structure of the material was demonstrated by X-ray photoelectron spectroscopy combined with ion beam sputtering. Using operando Raman spectroscopy, we monitored the reduction process of the catalyst surface oxide species at the applied potential. Density functional theory (DFT) calculations indicated that…

) upregulation played important roles in the initiation and progression of UC. On the basis of this, a biomimetic pH-responsive metal organic framework (MOF) carrier was constructed to deliver carbon nanodot-SOD nanozyme and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) (CRISPR/Cas9) system for site-specific treatment of UC. In this system, carbon nanodots (C-dots) and CD98 CRISPR/Cas9 plasmid were successfully encapsulated into MOF carrier (ZIF-8 nanoparticles) by a one-pot approach (formed as CCZ), and then camouflaged with macrophage membrane (formed as CCZM). It was worth noting that the C-dot nanozyme showed excellent superoxide dismutase (SOD) enzymatic activity, which could scavenge ROS effectively. As expected, this biomimetic system exhibited pH-responsive, immune escape, and inflammation targeting capability simultaneously. In vitro experiments showed that ROS was significantly eliminated, and CD98 was downregulated by CCZM. In the dextran sulfate sodium salt (DSS)-induced UC model, administration of CCZM…

Acute and chronic wounds, caused by trauma, tumors, diabetic foot ulcers, etc., are usually difficult to heal, while applying exogenous electrical stimulation to enhance the endogenous electric field in the wound has been proven to significantly accelerate wound healing. However, traditional electrical stimulation devices require an additional external power supply, making them poor in portability and comfort. In this work, a self-powered piezoelectric poly(vinyl alcohol) (PVA)/polyvinylidene fluoride (PVDF) composite hydrogel is constructed by establishing a distinctive preparation process of freezing/thawing-solvent replacement-annealing-swelling. The hydrogen bonding in the hydrogel is remarkably enhanced by the annealing-swelling process, which is stronger between PVA/PVDF molecules than that between PVA molecules, promoting transformation of the α-phase into the electroactive β-phase PVDF and facilitating formation of a much more crystalline structure with high cross-linking density. Hence, an obvious piezoelectric response with high piezoelectric coefficient and electrical…

Multimodal detection is a promising paradigm because of its advantages of expanding usage scenarios and improving reliability. However, it is very challenging to design reasonable strategies to achieve the multimodal sensing of targets. Herein, we developed an unprecedented bimodal ratiometric colorimetric/fluorometric method by exploring a novel bifunctional artificial oxidase mimic, Mn-doped N-rich carbon dots (Mn-CDs), to achieve the high-performance determination of nitrite in complicated matrices. The Mn-CDs exhibited both tunable photoluminescence and high oxidase-like activity, effectively catalyzing the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation to generate blue TMB + . When nitrite was introduced, the TMB + species generated would specifically react with nitrite to produce diazotized TMB +, resulting in a color change from blue to green and finally to yellow. Simultaneously, the fluorescence of Mn-CDs was quenched by the diazotized TMB + product via the inner filter effect. Hence, the existence of nitrite could lead to the simultaneous variations of visual…

Nanozyme technology as an emerging field has been successfully applied to chemical sensing, biomedicine, and environmental monitoring. It is very significant for the advance of this field to construct nanozymes with high catalytic activity by a simple method and to develop their multifunctional applications. Here, a new type of cobalt-doped carbon dots (Co-CDs) nanozymes was designed using vitamin B 12 and citric acid as the precursors. The homogeneous cobalt doping at carbon nuclear led the Co-CDs to show significant peroxidase-like activity resembling natural metalloenzymes. Based on the high affinity of Co-CDs to H 2 O 2 ( K m = 0.0598 mM), a colorimetric sensor for glucose detection was constructed by combining Co-CDs with glucose oxidase. On account of the high catalytic activity of nanozymes and the cascade strategy, a good linear relationship was obtained from 0.500 to 200 μM, with a detection limit of 0.145 μM. The biosensor has realized the accurate detection of glucose in human serum samples. Moreover, Co-CDs could specifically catalyze H 2 O 2 in cancer cells to generate…

Iron-based metal–organic frameworks (MOFs) have aroused extensive concern as prospective photocatalysts for antibiotic (e.g., tetracycline, TC) degradation. However, efficiencies of single and simple Fe-based MOFs still undergo restricted light absorption and weak charge separation. Assembly of different iron-based MOF building blocks into a hybrid MOF@MOF heterostructure reactor could be an encouraging strategy for the effective capture of antibiotics from the aqueous phase. This paper reports a new-style MIL-101(Fe)@MIL-100(Fe) photocatalyst, which was groundbreakingly constructed to realize a double win for boosting the performances of adsorption and photocatalysis. The optical response range, surface open sites, and charge separation efficiency of MIL-101(Fe)@MIL-100(Fe) can be regulated through accurate design and alteration. Attributed to the synergistic effects of double iron-based MOFs, MIL-101(Fe)@MIL-100(Fe) exhibits an excellent photocatalytic activity toward TC degradability compared to MIL-101(Fe) and MIL-100(Fe), which is even superior to those reported previously in…

A wearable textile that is engineered to reflect incoming sunlight and allow the transmission of mid-infrared radiation simultaneously would have a great impact on the human body's thermal regulation in an outdoor environment. However, developing such a textile is a tough challenge. Using nanoparticle-doped polymer (zinc oxide and polyethylene) materials and electrospinning technology, we have developed a nanofabric with the desired optical properties and good applicability. The nanofabric offers a cool fibrous structure with outstanding solar reflectivity (91%) and mid-infrared transmissivity (81%). In an outdoor field test under exposure of direct sunlight, the nanofabric was demonstrated to reduce the simulated skin temperature by 9 °C when compared to skin covered by a cotton textile. A heat-transfer model is also established to numerically assess the cooling performance of the nanofabric as a function of various climate factors, including solar intensity, ambient air temperature, atmospheric emission, wind speed, and parasitic heat loss rate. The results indicate that the…

Layered double hydroxides (LDHs) have attracted broad attention as cathode materials for hybrid supercapacitors (HSCs) because of their ultrahigh theoretical specific capacitance, high compositional flexibility, and adjustable interlayer spacing. However, as reported, specific capacitance of LDHs is still far below the theoretical value, inspiring countless efforts to these ongoing challenges. Herein, a hierarchical nanocage structure assembled by NiCo-LDH nanosheet arrays was rationally designed and fabricated via a facile solvothermal method assisted by the ZIF-67 template. The transformation from the ZIF-67 template to this hollow structure is achieved by a synergistic effect involving the Kirkendall effect and the Ostwald ripening process. The enlarged specific surface area co-occurred with broadened interlayer spacing of LDH nanosheets by finely increasing the Ni concentration, leading to synchronous improvement of electron/ion transfer kinetics. The optimized NiCo-LDH-210 electrode displays a maximum specific capacitance of 2203.6 F g –1 at 2 A g –1, excellent rate capability,…

Liposomes constitute the most exploited drug-nanocarrier with several liposomal drugs on the market. Microfluidic-based preparation methods stand up as a promising approach with high reproducibility and the ability to scale up. In this study, liposomes composed of DOPC, cholesterol, and DSPE-PEG 2000 with different molar ratios were fabricated using a microfluidic system. Process and conditions were optimized by applying design of experiments (DoE) principles. Furthermore, data were used to build an artificial neural network (ANN) model, to predict size and polydispersity index (PDI). Sets of runs were designed by DoE and performed on a micromixer microfluidic chip. Lipids' molar ratio and the process parameters, i.e. total flow rate (TFR) and flow rate ratio (FRR), were found to be the most influential factors on the formation of vesicles with target size and PDI under 100 nm and lower than 0.2, respectively. Size and PDI were predicted by the ANN model for 3 preparations with defined experimental conditions. The results showed no significant difference in size and PDI between the…

Examples of multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters that emit at longer wavelengths remain rare. To reach that goal, we decorate different numbers and types of electron-donors about a central MR-TADF core, DiKTa. Depending on the identity and number of donor groups, the excited state either remains short range charge transfer (SRCT) and thus characteristic of an MR-TADF emitter or becomes a long-range charge transfer (CT) that is typically observed in donor-acceptor TADF emitters. The impact is that in three examples, Cz-DiKTa, Cz-Ph-DiKTa and 3Cz -DiKTa, which emit from a SRCT state, the emission remains narrow, while in four examples, TMCz-DiKTa, DMAC-DiKTa, 3TMCz-DiKTa and 3DMAC-DiKTa, which emit via a CT state, the emission broadens significantly. Through this strategy, the organic light-emitting diodes fabricated with the three MR-TADF emitters show maximum electroluminescence emission wavelengths, EL, of 511, 492 and 547 nm with moderate full-width at half maxima (FWHM) of 62, 61 and 54 nm, respectively. Importantly, each of these devices…

The air-sensitivity of transition metal oxide cathode materials (Na x TMO 2, TM: transition metal) is a challenge for their practical application in sodium-ion batteries for large-scale energy storage. However, the deterioration mechanism of Na x TMO 2 under ambient air is unclear, which hinders the precise design of air-stable Na x TMO 2 . Here, we revealed the origin of Na x TMO 2 degradation by capturing the initial degradation status and microstructural evolution under ambient atmospheres with optimal humidity. It was found that the insertion of CO 2 into Na layers along (003) planes of Na x TMO 2 led to initial growth of Na 2 CO 3 nanoseeds between TM layers, which initiated fast structure degradation with surface cracks and extrusion of Na 2 CO 3 out of Na x TMO 2 . The degradation extents and pathways for Na x TMO 2 could be highly associated with crystal orientation, particle morphology, and ambient humidity. Interestingly, the deteriorated Na x TMO 2 could be completely healed through optimal recalcination, showing even improved air-stability and electrochemical…

High Resolution Image Download MS PowerPoint Slide Due to the excellent ion-sensing potential of covalent organic frameworks (COFs), the new imine-linked conjugated COF (IC-COF) is synthesized through a water-based synthesis reaction between 1,5-diaminonaphthalene and 2,4,6-tris(4-formylphenoxy)-1,3,5-triazine to create a luminescence sensor. It is noteworthy that the green synthesized IC-COF shows excellent selectivity to phosphate ions (PO 4 3– ) with a detection limit of 0.61 μM. The recyclability performance of IC-COF is high, indicating that it can be reused without a significant reduction in performance (5.2% decline after 5 cycles). Theoretical calculations using the density functional theory are performed on the IC-COF–PO 4 3– and IC-COF–Cu + complexes to explore the sensing mechanism. The fluorescence quenching in the presence of PO 4 3– ions is attributed to the difference between PO 4 3– binding sites to the IC-COF compared to Cu +, which leads to the considerable change in the IC-COF absorption spectrum from 400 to 600 nm.

Although Ti 3 C 2 T x MXene/fabric composites have shown promise as flexible pressure sensors, the effects of MXene composition and structure on piezoresistive properties and the effects of the textile structure on sensitivity have not been systematically studied. Herein, impregnation at room temperature was used as a cost-effective and scalable method to prepare composite materials using different fabrics [plain-woven fabric, twill-woven fabric, weft plain-knitted fabric, jersey cross-tuck fabric, and nonwoven fabric (NWF)] and MXene nanosheets (Ti 3 C 2 T x, Ti 2 CT x, Ti 3 CNT x, Mo 2 CT x, Nb 2 CT x, and Mo 2 TiC 2 T x ). The MXene nanosheets adhered to the fabric surface through hydrogen bonding, resulting in a conductive network structure. The Ti 3 C 2 T x @NWF composite was found to be the optimal flexible pressure sensor, demonstrating high sensitivity (6.31 kPa –1 ), a wide sensing range (up to 150 kPa), fast response/recovery times (300 ms/260 ms), and excellent durability (2000 cycles). Furthermore, the sensor was successfully used to monitor full-scale human motion,…

In the emerging Internet of Things (IoT) society, there is a significant need for low-cost, high-performance flexible humidity sensors in wearable devices. However, commercially available humidity sensors lack flexibility or require expensive and complex fabrication methods, limiting their application and widespread use. We report a high-performance printed flexible humidity sensor using a cellulose nanofiber/carbon black (CNF/CB) composite. The cellulose nanofiber enables excellent dispersion of carbon black, which facilitates the ink preparation and printing process. At the same time, its hydrophilic and porous nature provides high sensitivity and fast response to humidity. Significant resistance changes of 120% were observed in the sensor at humidity ranging from 30% RH to 90% RH, with a fast response time of 10 s and a recovery time of 6 s. Furthermore, the developed sensor also exhibited high-performance uniformity, response stability, and flexibility. A simple humidity detection device was fabricated and successfully applied to monitor human respiration and noncontact…

The high level of reactive oxygen species (ROS) and bacterial infection impede wound healing of the diabetic wound. Here, benefiting from the antioxidation effects of tannic acid (TA) and ROS-responsive phenylborate ester (PBAE), a series of ROS-responsive anti-inflammatory TA-conjugated nanoparticle hydrogels (PPBA-TA-PVA) can be obtained by conveniently mixing TA, phenylboric acid modified polyphosphazene (PPBA), and poly(vinyl alcohol) (PVA). The obtained PPBA-TA-PVA hydrogels could effectively inhibit the growth of Escherichia coli (antibacterial rate = 93.1 ± 1.1%) within 4 h and effectively scavenge both 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and •OH radicals in vitro . Besides, the cell migration rate of HDFa cells treated with PPBA-TA-PVA hydrogels (84.2 ± 4.6%) was twice the rate of normal cells (43.8 ± 8.1%) after 24 h of cocultivation. The clinical relevance was demonstrated further by assessing the PPBA-TA-PVA hydrogels in full-thickness excisional wounds in a streptozotocin (STZ)-induced diabetic rat model. The PPBA-TA-PVA hydrogels could act as effective…

High Resolution Image Download MS PowerPoint Slide As the most studied two-dimensional (2D) material from the MXene family, Ti 3 C 2 T x has constantly gained interest from academia and industry. Ti 3 C 2 T x MXene has the highest electrical conductivity (up to 24,000 S cm –1 ) and one of the highest stiffness values with a Young’s modulus of ∼ 334 GPa among water-dispersible conductive 2D materials. The negative surface charge of MXene helps to disperse it well in aqueous and other polar solvents. This solubility across a wide range of solvents, excellent interface interaction, tunable surface functionality, and stability with other organic/polymeric materials combined with the layered structure of Ti 3 C 2 T x MXene make it a promising material for anticorrosion coatings. While there are many reviews on Ti 3 C 2 T x MXene polymer composites for catalysis, flexible electronics, and energy storage, to our knowledge, no review has been published yet on MXenes’ anticorrosion applications. In this brief report, we summarize the current progress and the development of Ti 3 C 2 T x…

Fiber-shaped stretchable strain and temperature sensors are highly desirable for wearable electronics due to their excellent flexibility, comfort, air permeability, and easiness to be weaved into fabric. Herein, we prepare a smart ionogel-based fiber composed of thermoplastic polyurethane (TPU) and ionic liquid (IL) by the facile and scalable wet-spinning technique, which can serve as a wearable strain sensor with good linearity (a correlation coefficient of 0.997) in an ultrawide sensing range (up to 700%), ultralow-detection limit (0.05%), fast response (173 ms) and recovery (120 ms), and high reproducibility. Attributed to these outstanding strain sensing performances, the designed TPU/IL ionogel fiber-shaped sensor is able to monitor both subtle physiological activities and large human motions. More interestingly, because of the fast response and high resolution to strain, the fiber-shaped sensor can be sewn into the fabric to secretly encrypt and wirelessly translate message according to the principle of Morse code. More importantly, a wearable strain-insensitive temperature…

The rechargeable zinc–iodine (Zn–I 2 ) battery is a promising energy-storage system due to its low cost and good security, but the practical use of the battery is largely constrained by the shuttle effect and high dissolvability of iodides. Here a multifunctional iodine host, constructed with nitrogen-doped porous carbon nanocages (NCCs) by the polymerization carbonization activation method, is exploited to improve the electrochemical performance and lifespan of the Zn–I 2 battery, achieving a high specific capacity of 259 mAh g –1, a good rate performance (maintaining 50.6% expanding 50 times), and a high cycle stability (retention of 100% after 1000 cycles). On the basis of the experimental results and theoretical calculations, NCCs via the introduction of N doping and nanosized porous structure can simultaneously provide rich and robust anchoring and catalytic sites to carry out the electrostatic adsorption of iodides and facilitate the reversible conversion between iodine and iodides. This work shows a novel and efficient strategy to develop high-performance and long-life Zn–I 2…

Rationally integrating desired functional components into a composite material can endow the tailored function to achieve the corresponding purpose. This is the first case where a series of [AeImBr] X % -TAPT-COFs ( X = 0, 17, 33, 50, 67, 83, 100) were fabricated by chemically integrating the amino-functionalized imidazole ionic liquid (NH 2 -IL) onto channel walls of mesoporous covalent organic framework materials ([HO] X % -TAPT-COFs). By virtue of the polar groups (amino groups) and abundant imidazole cations of NH 2 -IL and its microporous nature, the obtained [AeImBr] X % -TAPT-COFs exhibit higher CO 2 capture activity than [HO] X % -TAPT-COFs. Correspondingly, the CO 2 equilibrium capture capacity increases from 62.6 to 117.4 mg/g, which is crucial to the storage of enough CO 2 around the catalytic active sites. Additionally, the synergistic effect of −NH 2 and Br – in NH 2 -IL can also improve the cycloaddition reaction rate. The characteristics of [AeImBr] X % -TAPT-COFs contribute to the efficient generation of cyclic carbonate through heterogeneously catalyzing CO 2…

Solar water splitting has emerged as an urgent imperative as hydrogen emerges as an increasingly important form of energy storage. g-C 3 N 4 is an ideal candidate for photocatalytic water splitting as a result of the excellent alignment of its band edges with water redox potentials. To mitigate electron–hole recombination that has limited the performance of g-C 3 N 4, we have developed a semiconductor heterostructure of g-C 3 N 4 with CuFe 2 O 4 nanoparticles (NPs) as a highly efficient photocatalyst. Visible-light-driven photocatalytic properties of CuFe 2 O 4 /g-C 3 N 4 heterostructures with different CuFe 2 O 4 loadings have been examined with two sacrificial agents. An up to 2.5-fold enhancement in catalytic efficiency is observed for CuFe 2 O 4 /g-C 3 N 4 heterostructures over g-C 3 N 4 nanosheets alone with the apparent quantum yield of H 2 production approaching 25%. The improved photocatalytic activity of the heterostructures suggests that introducing CuFe 2 O 4 NPs provides more active sites and reduces electron–hole recombination. The g-C 3 N 4 /CuFe 2 O 4 heterostructures…

In recent years, lignin has drawn increasing attention for different applications due to its intrinsic antibacterial and antioxidant properties, coupled with biodegradability and biocompatibility. However, chemical modification or combination with metals is usually required to increase its antimicrobial functionality and produce biobased added-value materials for applications wherein bacterial growth should be avoided, such as biomedical and food industries. In this work, a sonoenzymatic approach for the simultaneous functionalization and nanotransformation of lignin to prepare metal-free antibacterial phenolated lignin nanoparticles (PheLigNPs) is developed. The grafting of tannic acid, a natural phenolic compound, onto lignin was achieved by an environmentally friendly approach using laccase oxidation upon the application of high-intensity ultrasound to rearrange lignin into NPs. PheLigNPs presented higher antibacterial activity than nonfunctionalized LigNPs and phenolated lignin in the bulk form, indicating the contribution of both the phenolic content and the nanosize to the…

Single therapy for tumor therapy always exerts limited ability for the constraints on the reaction condition and the unavoidable multidrug resistance, which seriously influences the therapy effect in the clinic. Herein, a combination treatment nanosystem (MP@PI) based on chemodynamic therapy (CDT) and photothermal therapy (PTT) is constructed for triggering ferroptosis/pyroptosis, which is the metal–organic framework (MOF) modified with polydopamine (PDA) and IR820 to loaded with piperlongumine (PL). The MOF and PL respectively served as the iron source and H 2 O 2 source, performing chemodynamic therapy (CDT) for eliciting ferroptosis. Meanwhile the iron source induces pyroptosis in tumor cells. PDA is not only pH responsive to release PL but also CDT-assisted which due to PDA consumes the glutathione to decrease the expression of glutathione peroxide 4. The photosensitizer IR820 exerts photothermal effects under near-infrared light and further facilitates the ferroptosis/pyroptosis. In addation, the MP@PI nanoplatform evokes the immune response in vivo and enhances the antitumor…

The sunlight-driven fixation of CO 2 into valuable chemicals constitutes a promising approach toward environmental remediation and energy sustainability over traditional thermal-driven fixation. Consequently, in this article, we report a strategic design and utilization of Mg-centered porphyrin-based metal–organic framework (MOFs) having relevance to chlorophyll in green plants as a visible light-promoted highly recyclable catalyst for the effective fixation of CO 2 into value-added cyclic carbonates under ambient conditions. Indeed, the Mg-centered porphyrin MOF showed good CO 2 capture ability with a high heat of adsorption (44.5 kJ/mol) and superior catalytic activity under visible light irradiation in comparison to thermal-driven conditions. The excellent light-promoted catalytic activity of Mg–porphyrin MOF has been attributed to facile ligand-to-metal charge transfer transition from the photoexcited Mg–porphyrin unit (SBU) to the Zr 6 cluster which in turn activates CO 2, thereby lowering the activation barrier for its cycloaddition with epoxides. The in-depth theoretical…

Perovskite solar cells (PSCs) have shown great potential for next-generation photovoltaics. One of the main barriers to their commercial use is their poor long-term stability under ambient conditions and, in particular, their sensitivity to moisture and oxygen. Therefore, several encapsulation strategies are being developed in an attempt to improve the stability of PSCs in a humid environment. The lack of common testing procedures makes the comparison of encapsulation strategies challenging. In this paper, we optimized and investigated two common encapsulation strategies: lamination-based glass-glass encapsulation for outdoor operation and commercial use (COM) and a simple glue-based encapsulation mostly utilized for laboratory research purposes (LAB). We compare both approaches and evaluate their effectiveness to impede humidity ingress under three different testing conditions: on-shelf storage at 21 °C and 30% relative humidity (RH) (ISOS-D1), damp heat exposure at 85 °C and 85% RH (ISOS-D3), and outdoor operational stability continuously monitoring device performance for 10…

Simple, low-cost, and high-performance atmospheric water harvesting (AWH) still remains challenging in the context of global water shortage. Here, we present a simple and low-cost macroporous hydrogel for high-performance AWH to address this challenge. We employed an innovative strategy of pore foaming and vacuum drying to rationally fabricate a macroporous hydrogel. The hydrogel is endowed with a macroporous structure and a high specific surface area, enabling sufficient contact of the inner sorbent with outside air and high-performance AWH. The experiments demonstrate that macroporous hydrogels can achieve high-performance AWH with a broad range of sorption humidity [relative humidity (RH) from 100% to even lower than 20%], high water sorption capacity (highest 433.72% of hydrogel’s own weight at ∼98% RH, 25 °C within 60 h), rapid vapor capturing (the sorption efficiency is as high as 0.32 g g –1 h –1 in the first 3 h at 90% RH, 25 °C), unique durability, low desorption temperature (∼50 °C, lowest), and high water-releasing rate (release 99.38% of the sorbed water under 500 W m –2…

The combination of Cu and Ag presents a promising way to steer the CO 2 reduction products through regulating the surface active sites. However, the difficulty in forming the CuAg alloy with a controllable atomic ratio impedes the in-depth understanding of the structure–activity relationship of CuAg catalysts. Herein, we use E-beam evaporation to synthesize a series of CuAg films with uniform distribution and controllable stoichiometry to reveal the real reaction mechanism on CuAg for the electrochemical CO 2 reduction process. Compared with Cu, the Cu 1– x Ag x ( x = 0.05–0.2) alloy showed an apparent suppression of HCOOH and the ratio between C 2 liquid products (e.g., ethanol and acetate) and C 1 liquid product (HCOOH) is also increased. Operando synchrotron radiation Fourier transform infrared spectroscopy results suggest that the introduction of Ag into the Cu phase can significantly strengthen the absorbed *CO and *OCCO intermediates and suppress the O–C–O intermediates. This research provides a reliable way to inhibit the generation of HCOOH and enhance the production of…

Superbacteria-induced skin wound infections are huge health challenges, resulting in significant financial and medical costs due to notable morbidity and mortality worldwide. Probiotics are found in the skin and are effective in treating bacterial infection, moderating the microbial dysbiosis and inflammation induced by pathogens, regulating the immune system, as well as even promoting tissue repair. However, improving their colonization efficiency and viability remains a large obstacle for proper applications. Inspired by probiotic therapy and the natural extracellular matrix structure, hyaluronate-adipic dihydrazide/aldehyde-terminated Pluronic F127/fucoidan hydrogels loaded with Lactobacillus rhamnosus ( [email protected] ) with unique (bio)physicochemical characteristics were developed through the dynamic Schiff-base reaction for superbacteria-infected trauma management. The developed [email protected] exhibit a shortened gelation time, enhanced mechanical strength, and excellent self-healing and liquid-absorption abilities. Importantly, their anti-superbacteria ( Pseudomonas…

Two-dimensional (2D) layered transition-metal carbides (MXenes) are attractive faradic materials for an efficient capacitive deionization (CDI) process owing to their high capacitance, excellent conductivity, and remarkable ion storage capacity. However, the easy restacking property and spontaneous oxidation in solution by the dissolved oxygen of MXenes greatly restrict their further application in the CDI domain. Herein, a three-dimensional (3D) heterostructure (MoS 2 @MXene) is rationally designed and constructed, integrating the collective advantages of MXene flakes and MoS 2 nanosheets through the hydrothermal method. In such a design, the well-dispersed MXene flakes can effectively reduce the aggregation of MoS 2 nanosheets, boost electrical conductivity, and provide efficient charge transfer paths. Furthermore, MoS 2 nanosheets as the high-capacity interlayer spacer can prevent the self-restacking of MXene flakes and provide more active sites for ion intercalation. Meanwhile, the strong chemical interactions between MXene flakes and MoS 2 nanosheets contribute to accelerating…

The use of porous materials as the core for synthesizing molecularly imprinted polymers (MIPs) adds significant value to the resulting sensing system. This review covers in detail the current progress and achievements regarding the synergistic combination of MIPs and porous materials, namely metal/covalent-organic frameworks (MOFs/COFs), including the application of such frameworks in the development of upgraded sensor platforms. The different processes involved in the synthesis of MOF/COF-MIPs are outlined, along with their intrinsic properties. Special attention is paid to debriefing the impact of the morphological changes that occur through the synergistic combination compared to those that occur due to the individual entities. Thereafter, the strategies used for building the sensors, as well as the transduction modes, are overviewed and discussed. This is followed by a full description of research advances for various types of MOF/COF-MIP-based (bio)sensors and their applications in the fields of environmental monitoring, food safety, and pharmaceutical analysis. Finally, the…

The surface structure and topography of biomaterials play a crucial role in directing cell behaviors and fates. Meanwhile, asymmetric dressings that mimic the natural skin structure have been identified as an effective strategy for enhancing wound healing. Inspired by the skin structure and the superhydrophobic structure of the lotus leaf, an asymmetric composite dressing was obtained by constructing an asymmetric structure and wettability surface modification on both sides of the sponge based on electrospinning. Among them, the collagen and quaternized chitosan sponge was fabricated by freeze-drying, followed by an aligned poly(ε-caprolactone) (PCL)/gelatin nanofiber hydrophilic inner layer and hierarchical micronanostructure PCL/polystyrene microsphere highly hydrophobic outer layer constructed on each side of the sponge. The proposed asymmetric composite dressing combines topological morphology with the material’s properties to effectively prevent bacterial colonization/infection and promote wound healing by directing cellular behavior. In vitro experimental results confirmed…

Transition-metal oxides (TMOs) are promising anode materials for high-performance lithium-ion batteries (LIBs) because of their abundant reserves and high theoretical capacity. However, the poor conductivity, unstable solid electrolyte interface (SEI) film, and poor cycling stability still limit their practical applications. As a novel kind of anode material, a high-entropy oxide (HEO) is a single-phase crystal structure composed of multiple metal elements, demonstrating a huge potential for energy storage applications due to the synergistic effect of various metal species. Herein, we have designed the porous spinel-phase HEO (Cr 0.2 Fe 0.2 Co 0.2 Ni 0.2 Zn 0.2 ) 3 O 4 synthesized at low temperature by a sol–gel method. On the one hand, the unique porous nanostructure not only promotes transport of the electrolyte but also alleviates the volume change of active materials upon cycling. On the other hand, the stabilization effect of entropy can suppress the formation of cation short-range order within the crystalline structure of HEO by a lattice distortion effect, thus guaranteeing a…

Although advances in industrial products have brought convenience to our lives, severe weather has increased the safety risks to industrial facilities. Considerable efforts have been made to develop high-performance superhydrophobic anti-icing coatings. Nevertheless, designing a functional coating with both anti-icing properties and self-deicing remains a major challenge. Here, we propose a design strategy to exploit a photothermal superhydrophobic multifunctional coating with excellent anti-icing and deicing properties based on MXene by high-temperature sintering and layer-by-layer coating. Specifically, poly(tetrafluoroethylene) (PTFE) particles provide low surface energy and binding effects. Room-temperature-vulcanized silicone rubber (RTV) enhances the dispersion of the composite particles and the adhesion of the functional coating to a glass substrate. Furthermore, the functional coatings constructed with MXene exhibit outstanding photothermal effects, imparting excellent superhydrophobicity (CA = 160.18°, SA = 1.8°) and efficient photothermal conversion (equilibrium…

Low-dimensional organic–metal halides are regarded as an emerging class of X-ray scintillation materials, but most of the discovered compounds are confronted with challenges of toxicity and instability. To address these challenges, we herein report two lead-free zero-dimensional (0D) hybrid halides, (Bmpip) 2 Cu 2 Br 4 and PPh 4 CuBr 2 single crystals, grown by the low-cost solution-processing method. By single-crystal X-ray diffraction refinement, the crystal structures of (Bmpip) 2 Cu 2 Br 4 and PPh 4 CuBr 2 were determined to be orthorhombic and monoclinic crystal systems, respectively. (Bmpip) 2 Cu 2 Br 4 and PPh 4 CuBr 2 show broadband orange and yellow emissions peaking at 620 and 538 nm, respectively. Different from the emission nature of the recent reported Cu-based halide hybrids, both (Bmpip) 2 Cu 2 Br 4 and PPh 4 CuBr 2 emit from excitons bound to defects featuring spin-allowed transition, enabling them to possess fast scintillation decay time of tens of nanoseconds, respectively. In particular, the (Bmpip) 2 Cu 2 Br 4 single crystal has a high photoluminescence quantum…

Underwater adhesion plays an essential role in soft electronics for the underwater interface. Although hydrogel-based electronics are of great interest, because of their versatility, water molecules prevent hydrogels from adhering to substrates, thus bottlenecking further applications. Herein, inspired by the barnacle proteins, MXene/PHMP hydrogels with strong repeatable underwater adhesion are developed through the random copolymerization of 2-phenoxyethyl acrylate, 2-methoxyethyl acrylate, and N -(2-hydroxyethyl) acrylamide with the presence of MXene nanosheets. The hydrogels are mechanically tough (elastic modulus of 32 kPa, fracture stress of 0.11 MPa), and 2-phenoxyethyl acrylate (PEA) with aromatic groups endows the hydrogel with nonswelling property and prevents water molecules from invading the adhesive interface, rendering the hydrogels an outstanding adhesive behavior toward various substrates (including glass, iron, polyethylene terephthalate (PET), porcine). Besides, dynamic physical interactions allow for instant and repeatable underwater adhesion. Furthermore, the…

It is a great challenge for traditional hydrogel-based sensors to be effective underwater due to unsatisfactory water resistance and insufficient wet adhesion. Herein, a tough supramolecular hydrogel aiming at underwater sensing is prepared by the modification of hydrophilic poly(acrylic acid) (PAA) with a small amount of hydrophobic lauryl methacrylate (LMA) in the presence of high concentrations of the cationic surfactant cetyltrimethylammonium bromide (CTAB). Owing to the synergistic effects of the electrostatic interactions and hydrophobic associations of CTAB with the P(AA- co -LMA) copolymer, the hydrogel with a water content of approximately 58.5 wt % demonstrates outstanding anti-swelling feature, superior tensile strength (≈1.6 MPa), large stretchability (>900%), rapid room-temperature self-recovery (≈3 min at 100% strain), and robust wet adhesion to diverse substrates. Moreover, the strain sensor based on the hydrogel displays keen sensitivity in a sensing range of 0–900% (gauge factor is 0.42, 3.44, 5.44, and 7.39 in the strain range of 0–100, 100–300, 300–500, and…

Although two-dimensional transition-metal carbides (MXenes) and intrinsic conductive polymers have been combined to produce functional electromagnetic interference (EMI) shielding composites, acid/alkali-responsive EMI shielding textiles have not been reported. Herein, electrically conductive polyaniline (PANI)/MXene/cotton fabrics (PMCFs) are fabricated by an efficient vacuum filtration-assisted spray-coating method for acid/alkali-responsive and tunable EMI shielding applications on the basis of the high electrical conductivity of MXene sheets and the acid/alkali doping/de-doping feature of PANI nanowires. The as-prepared PMCF exhibits a sensitive ammonia response of 19.6% at an ammonia concentration of 200 ppm. The high EMI shielding efficiency of ∼54 dB is achieved by optimizing the decorated structure of the PANI/MXene coating on the cotton fabrics. More importantly, the PMCF can act adaptively as a "switch" for EMI shielding between the efficient strong shielding of 24 dB and the inefficient weak shielding of 15 dB driven by the stimulation of hydrogen chloride and ammonia…

Flexible sensing devices (FSDs) fabricated using conductive hydrogels have attracted researchers’ extensive enthusiasm in recent years due to their versatility. Considering the complexity of their application environments, the integration of various functional characteristics (e.g., excellent mechanical, antibacterial, and antifreezing properties) is an important guarantee for FSDs to stably perform their applications in different environments. Herein, we developed a multifunctional conductive polyvinyl alcohol (PVA) organohydrogel PVA-CT-Ag-Al-Gly (PCAAG) by using a green, natural, and cheap biomass, chestnut tannin (CT), as a crosslinking agent, nano-silver particles (AgNPs) as an antimicrobial agent, aluminum trichloride (AlCl 3 ) as a conducting medium, and the mixed water–glycerol as the solvent system. In this organohydrogel system, CT acted not only as the reducing and stabilizing agent for the preparation of antibacterial AgNPs but also as the crosslinking agent owing to its strong multiple hydrogen bonding interactions with PVA, realizing its multifunctional application.…

The integration of renewable solar energy-driven interfacial evaporation and photocatalysis has recently emerged as one of the most promising technologies for simultaneous freshwater production and pollutant removal. However, the construction of an advanced integrated system with the merit of a fast supply of water and pollutant molecules remains challenging for efficient solar-driven evaporation and photocatalytic performance. Herein, inspired by the transpiration of plants, we fabricate a biomimetic, vertically channeled polypyrrole/foam-like carbon nitride/poly(vinyl alcohol) hydrogel (PCH) by directional freeze-drying. We prove that the vertically aligned channels not only reduce heat loss and improve energy conversion efficiency but also facilitate the transport of water and organic pollutants to the air–water interface. Benefiting from the advantages above, the PCH evaporator presents a high solar evaporation efficiency of 92.5%, with the evaporation rate achieving 2.27 kg m –2 h –1 under 1 kW m –2 irradiation, exceeding many advanced interfacial solar-driven evaporators.…

Metal-organic frameworks (MOFs) are booming as a promising precursor for constructing lightweight, high-efficiency microwave absorbing (MA) material. However, it is still a challenge to rationally design three-dimensional (3D), porous MOF-derived MA materials with a stable structure and strong and wideband MA performance. Herein, a 3D hybrid nanostructure (CNT/FeCoNi@C) comprising MOF-derived magnetic nanospheres and Fe-filled carbon nanotube (CNT) sponge has been controllably fabricated to enhance the absorption ability and broaden the effective absorption bandwidth (EAB). The magnetic nanospheres are uniformly anchored on the CNT skeleton, forming hybrid network structures, which enhance interface polarization, electron transportation, and impedance matching. The minimum reflection loss (RL) and EAB of the as-prepared CNT/FeCoNi@C sponges reach -51.7 dB and 6.0 GHz, respectively, outperforming most reported MOF-based wave absorbers. This work provides not only a novel design of MOF-derived 3D nanostructures but also an effective guide for the optimization of electromagnetic…

Antibacterial treatment that provides on-demand release of therapeutics that can kill a broad spectrum of pathogens while maintaining long-term efficacy and without developing resistance or causing side effects is urgently required in clinical practice. Here, we demonstrate the development of a multistimuli-responsive hydrogel, prepared by cross-linking N -isopropylacrylamide with acrylic acid and loaded with ultrasmall silver nanoparticles (AgNPs), offering the on-demand release of Ag + ions triggered by changes in the wound microenvironment. We demonstrate that this dual-responsive hydrogel is highly sensitive to a typical wound pH and temperature change, evidenced by the restricted release of Ag + ions at acidic pH (<5.5) while significantly promoting the release in alkaline pH (>7.4) (>90% release). The pH-dependent release and antibacterial effect show minimal killing at pH 4 or 5.5 but dramatically activated at pH 7.4 and 10, eliminating >95% of the pathogens. The in vivo antibacterial efficacy and safety showed a high potency to clear Staphylococcus aureus wound infection…

Currently, with the development of electronic skins (e-skins), wearable pressure sensors with low energy consumption and excellent wearability for long-term physiological signal monitoring are urgently desired but remain a challenge. Capacitive-type devices are desirable candidates for wearable applications, but traditional capacitive pressure sensors are limited by low capacitance and sensitivity. In this study, an all-nanofibrous ionic pressure sensor (IPS) is developed, and the formation of an electrical double layer at the electrode/electrolyte contact interface significantly enhances the capacitance and sensing properties. The IPS is fabricated by sandwiching a nanofibrous ionic gel sensing layer between two thermoplastic polyurethane nanofibrous membranes with graphene electrodes. The IPS has a high sensitivity of 217.5 kPa –1 in the pressure range of 0–5 kPa, which is much higher than that of conventional capacitive pressure sensors. Combined with the rapid response and recovery speed (30 and 60 ms), the IPS is suitable for real-time monitoring of multiple physiological…

Terahertz wave manipulations, especially the phase manipulations, through metasurfaces has attracted considerable interests. Here, we develop a terahertz beam steering device using the liquid-crystal (LC)-integrated programmable metasurface. Specifically, a reflective-type 1 bit metasurface element is designed by employing a multilayer structure composed of metallic back plate-LC-complementary split ring resonator (CSRR). Numerical simulations show that, at the optimized operation frequency of 0.675 THz, the developed metasurface element has a nearly 180° phase difference between unbiased and biased states with close reflection amplitudes. Furthermore, a one-dimensional programmable metasurface array with 32 independently controlled subarrays is designed and fabricated using the lithography technology. Both simulated and measured far-field scattering patterns of the metasurface certify the anomalous beam reflection and wide-angle beam steering performances. Nevertheless, the optimal frequency red shifts to 0.645 THz in the experiment. This work may advance the application of…

Microenvironment-responsive hydrogels present high potential in treating refractory wounds due to their capability of on-demand drug release. In this study, a specially designed hydrogel with smart targeting of refractory wound characteristics was designed to treat chronically infected diabetic wounds. Aminated gelatin reacted with oxidized dextran, forming a hydrogel cross-linked with a dynamic Schiff base, which is sensitive to the low-pH environment in refractory wounds. Nano-ZnO was loaded into the hydrogel for killing microbes. A Paeoniflorin-encapsulated micelle with a ROS-responsive property was fixed to the skeleton of the hydrogel via a Schiff base bond for low-pH- and ROS-stimulated angiogenic activity. The sequential responsiveness of the novel hydrogel enabled smart rescue of the deleterious microenvironment in refractory wounds. This highly biocompatible hydrogel demonstrated antibacterial and angiogenic abilities in vitro and significantly promoted healing of chronically infected diabetic wounds via sequential hemostatic, microbe killing, and angiogenic activities.…

Delicately aligned structures of two-dimensional (2D) MXene nanosheets have demonstrated positive effects on applications, especially in electromagnetic interference (EMI) shielding and infrared (IR) stealth. However, precise regulation of structural assembly by theory-guided solution processing is still a great challenge. Herein, one-dimensional (1D) cellulose nanofibers (CNFs) with a high aspect ratio are applied as a reinforcing agent and a rheological modifier for MXene/CNF colloids to fabricate aligned MXene-based materials for EMI shielding and IR stealth. Notably, a systematical rheological study of the MXene/CNF colloids is proposed to determine the optimal solution-processing conditions for finely oriented component arrangement requirements and provides in-depth information on the interactions between the components. The delicately regulated orientation structure assembled by shear inducement is convincingly demonstrated through micro-CT and wide-angle X-ray diffraction/small-angle X-ray scattering (WAXD/SAXS), which endows the MXene/CNF film with a significantly enhanced…

The rapid development of flexible electronic devices has caused a boom in researching flexible sensors based on hydrogels, but most of the flexible sensors can only work at room temperature, and they are difficult to adapt to extremely cold or dry environments. Here, the flexible hydrogel fibers (PEDOT:PSS@PVA) with excellent resistance to extreme environments have been prepared by adding glycerin (GL) to the mixture of poly(vinyl alcohol) (PVA) and poly 3,4-dioxyethylene thiophene:polystyrene sulfonic acid (PEDOT:PSS) because GL molecules can form dynamic hydrogen bonds with an elastic matrix of PVA molecules. It is found that the prepared sensor exhibits very good flexibility and mechanical strength, and the ultimate tensile strength can reach up to 13.76 MPa when the elongation at break is 519.9%. Furthermore, the hydrogel fibers possess excellent water retention performance and low-temperature resistance. After being placed in the atmospheric environment for 1 year, the sensor still shows good flexibility. At a low temperature of -60 °C, the sensor can stably endure 1000…

Lithium separation is of great significance to overcome the lithium supply shortage resulting from a heightened demand in the energy sector. The low selectivity of polymer nanofiltration membranes for lithium extraction from concentrated Mg/Li mixtures caused by miniaturized pore structures and weak and unstable positive surface charges limits their practical implementation. To address the surface charge strength and stability, a novel ionic liquid monomer, N 1 -(6-aminohexyl)-N 1,N 1,N 6,N 6,N 6 -pentamethylhexane-1,6-diaminium bromide (denoted as DABIL), is first synthesized and covalently anchored on a pristine polyamide thin-film composite (TFC) membrane via a secondary amidation reaction for improved selective lithium separation from Mg/Li mixtures. DABIL modification of the polyamide network contributes to increased surface hydrophilicity, an enlarged membrane pore structure, and reinforced Donnan exclusion effects. Molecular dynamics simulation confirmed that the difference of the interaction energies between water and the multication groups dominates the surface properties.…

To achieve chromium tolerance and high performance, a new series of high-entropy perovskites (HEPs) are investigated as cathode materials for solid oxide fuel cells (SOFCs). Multiple rare-earth, alkaline-earth, and high-order transition metal elements are used for the A-site of this ABO 3 structure. A pure phase is achieved through the designed combination of different elements in seven out of eight candidates. Due to the retaining of alkaline-earth elements Sr and/or Ba, the electrical conductivities of these HEPs are in the order of 100 S/cm at 550–700 °C, a value that can practically eliminate the electronic resistance of the porous cathode. Three out of eight candidates show similar or better performance than the (La 0.6 Sr 0.4 )(Co 0.2 Fe 0.8 )O 3−δ (LSCF) benchmark. It is found that A-site elements can cast a substantial influence on the overall performance even with a change as small as 10% of the total cations. It seems that each element has its individual “phenomenal activity” that can be transferred from one candidate to the other in the general setting of the perovskite…

Fluorescent materials presenting unique color changes in response to external stimuli have wide applications in information storage and anticounterfeiting. However, developing intelligent fluorescent materials with high security levels and dynamically displaying encrypted information is still a challenge. Herein, we report a new method for constructing excellent fluorescent materials by loading the photochromic molecule spiropyran into a lanthanide metal-organic framework. Controlling the isomerization of the spiropyran unit regulates the fluorescence resonance energy transfer (FRET) mechanism between the spiropyran acceptor and the lanthanide donor, leading to an exceptional reversible absorption/luminescence modulation ability. As the irradiation time is extended, the fluorescent color changes continuously from yellow-greenish to orange and then to red through the FRET process within 60 s. This composite system has great potential in anticounterfeiting because of the following advantages: (1) the materials have different fluorescence emissions and optical colors regulated by…

Electrocatalytic nitrate reduction is promising as an environmentally friendly process to produce high value-added ammonia with simultaneous removal of nitrate, a widespread nitrogen pollutant, for water treatment; however, efficient electrocatalysts with high selectivity are required for ammonia formation. In this work, FeOOH nanorod with intrinsic oxygen vacancy supported on carbon paper (FeOOH/CP) is proposed as a high-performance electrocatalyst for converting nitrate to ammonia at room temperature. When operated in a 0.1 M phosphate-buffered saline (PBS) solution with 0.1 M NaNO 3, FeOOH/CP is able to obtain a large NH 3 yield of 2419 μg h –1 cm –2 and a surprisingly high Faradic efficiency of 92% with excellent stability. Density functional theory calculation demonstrates that the potential-determining step for nitrate reduction over FeOOH (200) is *NO 2 H + H + + e – → *NO + H 2 O.

A new environmentally friendly and economical recycling process for extracting metals from spent lithium-ion batteries (LIBs) using sulfuric acid and malonic acid as leaching agents is proposed. By applying Box–Behnken design (BBD) and response surface methodology (RSM) optimization techniques, the global optimal solution of the maximum leaching rate of metals in spent LIBs is realized. The results show that under the optimal conditions of 0.93 M H 2 SO 4, 0.85 M malonic acid, and a liquid/solid ratio of 61 g·L –1, a temperature of 70 °C and 5 vol % of 30% H 2 O 2, 99.79% Li, 99.46% Ni, 97.24% Co, and 96.88% Mn are recovered within 81 min. The error between the theoretical value and the actual value of the metal leaching rate predicted by the regression model is less than 1.0%. Additionally, the study of leaching kinetics reveals that the leaching process of Li, Ni, Co, and Mn in spent cathode materials was affected by the synergistic effect of interfacial mass transfer and solid product layer diffusion. Economic analysis reveals that evaluation index should be fully considered when…

The giant magnetoresistance (GMR) effect has seen flourishing development from theory to application in the last three decades since its discovery in 1988. Nowadays, commercial devices based on the GMR effect, such as hard-disk drives, biosensors, magnetic field sensors, microelectromechanical systems (MEMS), etc., are available in the market, by virtue of the advances in state-of-the-art thin-film deposition and micro- and nanofabrication techniques. Different types of GMR biosensor arrays with superior sensitivity and robustness are available at a lower cost for a wide variety of biomedical applications. In this paper, we review the recent advances in GMR-based biomedical applications including disease diagnosis, genotyping, food and drug regulation, brain and cardiac mapping, etc. The GMR magnetic multilayer structure, spin valve, and magnetic granular structure, as well as fundamental theories of the GMR effect, are introduced at first. The emerging topic of flexible GMR for wearable biosensing is also included. Different GMR pattern designs, sensor surface functionalization,…

There has been a direct correlation between the rate of industrial development and the spread of pollution on Earth, particularly in the last century. The organic and inorganic pollutants generated from industrial activities have created serious risks to human life and the environment. The concept of sustainability has emerged to tackle the environmental issues in developing chemical-based industries. However, pollutants have continued to be discharged to water resources, and finding appropriate techniques for the removal and remedy of wastewater is in high demand. Chromium is one of the high-risk heavy metals in industrial wastewaters that should be removed via physical adsorption and/or transformed into less hazardous chemicals. Photocatalysis as a sustainable process has received considerable attention as it utilizes sunlight irradiation to remedy Cr (VI) via a cost-effective process. Numerous photocatalytic systems have been developed up to now, but metal–organic frameworks (MOFs) have gained growing attention because of their unique versatilities and facile structural…

Rationally developing an intelligent tool for high-contrast fluorescence imaging of latent fingerprints (LFPs) is gaining much concern in many applications such as medical diagnostics and forensic investigations. Herein, the off–on fluorescent polymer micelles (PMs) have been rationally designed and synthesized for high-contrast fluorescence imaging of LFPs through the cross-linking reaction of hydrazine (N 2 H 4 ) and aldehyde group of polymer. Excitingly, the cross-linking (N 2 H 4 ) induced emission of PMs has the property of aggregation-induced emission (AIE) and excited state intramolecular proton transfer (ESIPT), which could effectively address the notorious aggregation-caused quenching (ACQ) effects of conventional organic dyes. In addition, the cross-linking strategy can not only improve structural stability of PMs but also enhance its fluorescence brightness. The experiment results demonstrated that PMs showed high water dispersibility (100% aqueous solution), high selectivity, large Stokes shift (∼150 nm), good photostability, and excellent long-term stability. Because of…