The low initial Coulombic efficiency (ICE) for the electrodes which stems from electrolyte decomposition and irreversible sodium uptake by the material itself, is one of the reasons limiting the large-scale sodium-ion capacitors (SICs). Here, we report a simple but precise bifunctional pre-sodiation of the Nb2O5 anode (as a typical example) using sodium naphthalene/2-methyltetrahydrofuran as a pre-sodiated agent. The pre-sodiated agent realizes the pre-activation to achieve stable cycling of NaxNb2O5, thus compensating the irreversible Na uptake. Moreover, this process offsets the electrolyte decomposition loss, and facilitates the formation of a robust inorganic-rich solid electrolyte interphase layer. Stable and high-energy SIC devices are achieved by compensating the interphase and bulk sodium loss of Nb2O5 anodes. This work provides new insights into tuning the ICE of sodium-storage electrodes for next-generation and scaled-up applications of SICs.

It is necessary to construct hierarchically porous photocatalysts to ensure high light absorption and electrochemical kinetics in photocatalysis. Carbon nitride (g-C3N4) appears to be a favorable choice, especially the tunable hollow micro/nanostructure. However, the facile preparation of g-C3N4 with hierarchical pores still faces challenge. Here, we firstly report a facile preparation of hierarchically porous g-C3N4 with uniform organic microstructure as a soft template. The template is in situ formed in thiourea precursor solution, and its similar π-conjugated structure to g-C3N4 makes it effective in modifying the condensation of g-C3N4. The layer thickness of the as-prepared g-C3N4 is about 3–4 nm. And the resultant g-C3N4 possesses hierarchical meso/macropores with a specific surface area of 27.34 m2 g−1 and pore volume of 0.18 cm3 g−1, approximately 6.2 and 9.0 times, respectively, higher than that of the unmodified one. This favors the charge/mass transport process, hence rendering the catalyst a 2.4-fold enhancement in photodegrading organic pollutant with H+ and ·O −2 as the predominant species. At the same time, the photostability can be guaranteed with only 20% loss of its efficiency after long-term use.

Anhydrous copper(II) fluoride (CuF2) has a high specific capacity of 528 mA h g−1 with an operating voltage of 3.55 V vs. Li/Li+, achieving a high gravimetric energy density of 1874 W h kg−1, which makes it a promising cathode candidate for next-generation rechargeable lithium (Li) batteries. However, the notorious dissolution of Cu during charging triggers the rapid failure of the CuF2 cathode, impeding its development. In this work, the reversibility of the anhydrous CuF2 electrode was enabled via the use of a fluorinated high-concentration (FHC) electrolyte to effectively suppress the dissolution of Cu. With the FHC electrolyte, the CuF2-Ketjen Black nanocomposite cathode delivered a reversible capacity of 228 mA h g−1 after 30 cycles, which nearly tripled that of the baseline electrolyte. Thus, the strategy of electrolyte engineering is proposed to harness CuF2 as a high-capacity cathode material for Li batteries.

As a type of wound dressings, adhesive hydrogel dressings have been studied widely. However, due to the problems of moisture loss and secondary damage during dressing changes, the clinical application of adhesive hydrogel dressing remains a significant challenge. Herein, we developed a water-retaining and separable adhesive hydrogel wound dressing composed of methacrylated silk fibroin (SFMA), tannic acid (TA), and urethane diacrylate (UDA). The addition of TA with an abundance of catechol groups endowed the hydrogel with improved mechanical properties, good tissue adhesion and hemostasis abilities. Then, a hydrophobic polyurethane diacrylate (PUA) coating encapsulated the hydrogel by UDA polymerization, which could maintain the long-lasting high water content of the hydrogel. Furthermore, due to the adhesion energy being higher than the fracture energy of the hydrogel, it could be separated upon peeling. Finally, the animal experiments indicated that this adhesive hemostatic hydrogel could increase wound healing efficiency by maintaining long-lasting moist environment and being changed without secondary damage. These results showed that the multifunctional hydrogel might be a promising wound dressing for clinical application.

Wide-bandgap metal oxide semiconductor (MOS) nanofiber neuromorphic transistors (NFNTs) can be potentially used to construct low-power bio-inspired artificial circuits. However, the cation ratio of MOS used for NFNTs is mostly adopted without detailed reasons in literature. In this study, we have for the first time focused on systematically tuning the cation ratio of indium zinc oxide (InZnO)-based NFNTs, fabricated by a low-cost electrospinning technique combined with a facile nanofiber transfer process. These electrical-driven NFNTs based on double-cation InZnO nanofibers can greatly simplify experimental procedures. Among the cation ratios of InxZn1−xO (x = 0.6, 0.7, 0.8, 0.9), we found that NFNTs based on In0.7Zn0.3O exhibited the lowest excitatory postsynaptic currents and offered electrical benefits for low-power operations and synaptic function simulations. The rational tuning of MOS nanofiber composition opens the door for high-performance low-power NFNTs.

负泊松比超材料由于其优异的力学性能, 包括优异的抗剪切性能、抗冲击性能、抗断裂性能、吸能隔振等, 在个体防护和抗冲击、减振吸能等领域有着重要的应用价值, 从而引起了科学家和工程师们极大的研究兴趣. 大多数传统的负泊松比超材料通常基于单元胞体的拓扑结构设计, 这类超材料通常不可避免地面临着由其复杂拓扑结构,特别是内凹多边形结构, 所带来的设计、制备难题. 迄今为止, 尽管许多研究人员致力于开发新的负泊松比超结构和材料, 但很少有研究能明确指出负泊松比超材料的设计指南或工作流程, 更多的研究是基于研究人员的设计灵感和对特定胞元结构的计算机辅助优化. 基于此, 我们提出了一种受自然启发的负泊松比超材料设计策略, 利用天然多孔材料所具有的独特双梯度结构, 例如以松质骨和向日葵茎髓心作为生物模型, 通过在多孔结构中引入双梯度变化即可得到负泊松比效应, 从而制备负泊松比超材料. 这种受自然启发的负泊松比超材料设计思路具有一定的普适性, 可以扩展到具有常见凸多边形胞元的多孔结构中,基本胞元结构并不局限于特定的内凹多边形等常见的用来构造负泊松比超材料的结构和形状.

Molybdenum oxide (MoO3) is an attractive anode material for lithium-ion batteries (LIBs); however, its low electrical conductivity, large volume expansion after lithiation, and slow Li-ion diffusion kinetics severely limit its practical applications. Here, ultrafine MoO3 nanoparticles (NPs) (10–15 nm) are synthesized from heavily Mo/N-doped carbonaceous precursors, resulting in MoO3 NPs confined in an N-doped carbon network. This design allows fast electron conduction and short Li-ion diffusion paths; meanwhile, abundant N species and O vacancies on the MoO3 surface lower the Li-ion adsorption barrier and together contribute to the durable Li-ion storage at high current rates. Notably, the obtained nanocomposite NC-MoO3 exhibits a high capacity of 1362 mA h g−1 (0.1 A g−1) and maintains a reversible capacity of 394 mA h g−1 at 10.0 A g−1. A coin-type full LiFePO4//NC-MoO3-400 cell obtains a large specific capacity of 81 mA h g−1 at 5 C. Our work inspires the design and confinement synthesis of other transition metal oxides embedded in conducting carbon networks for practical LIB applications.

Developing perovskite-based tandem solar cells (TSCs) is a promising technique to surpass the Shockley-Queisser limit set for single-junction solar cells. Encouragingly, all the perovskite-based TSCs, including perovskite/silicon, perovskite/perovskite, perovskite/copper indium gallium selenide and perovskite/organic tandems have demonstrated higher efficiency than the corresponding single-junction solar cells, showing great potential for further breakthroughs. In tandem devices, charge transport materials (CTMs) are vital components of perovskite sub-cells that directly determine the charge transportation and energy loss. Generally, high conductivity and transmittance, favorable energy-level alignment and chemical stability are crucial for CTMs for tandem applications. To date, various CTMs including conductive metallic oxides, organic molecules, polymers, fullerenes, and self-assembled materials have been extensively employed in highly efficient TSCs. In this review, we first summarize the recent progress of CTMs for different types of monolithic perovskite-based TSCs, in which the electrical and optical properties of CTMs and their influence on device performance are carefully discussed. Then we put forward the challenges and outlook for the further development of CTMs for tandem applications. This comprehensive review will provide effective guidance for device design for different perovskite-based TSCs.

Increasing resistance to carbapenem antibiotics has become a particular concern. Combination therapy might constitute an effective way to control drug-resistant bacterial infections. Here, we show that AuRh nanoparticles (NPs) have a synergistic antibacterial effect with a small-molecule antibiotic (imipenem), and they exhibit excellent antibacterial efficacies by increasing intracellular reactive oxygen species levels and enhancing the permeability of the bacterial membrane. In particular, the combination therapy restores the efficacy of imipenem against carbapenem-resistant Klebsiella pneumoniae (CRKP), with a 128-fold reduction in the minimum inhibitory concentration. In the treatment of lung infections, the combination of AuRh NPs (2 mg kg−1) and imipenem (2 mg kg−1) more effectively inhibits CRKP infection, with a 50% increase in the survival rate of mice compared with groups treated with imipenem or AuRh NPs alone. For in vitro and in vivo safety studies, AuRh NPs combined with imipenem show no significant toxicity, even at an injected concentration of 100 mg kg−1 in mice. This combination therapeutic provides an effective treatment for drug-resistant bacterial infections.

Because of its high capacity, availability, and environmental friendliness, copper oxide (CuO) is a desirable anode material for lithium-ion batteries (LIBs). However, due to low intrinsic electrical conductivity and enormous volume expansion during cycling, the capacity utilization and cycle stability of the CuO anode remain insufficient for battery applications. In this study, we design and fabricate a three-dimensional (3D) porous carbon@CuO composite (C@CuO) by in situ synthesis of CuO nanosheets directly on the internal and external walls of chitin-derived carbon microspheres. Benefiting from the hierarchical conductive framework of the carbon microspheres and a rational distribution of CuO nanosheets, the capacity utilization and structural stability of the CuO nanosheets are substantially improved during the charge/discharge process. Thus, the C@CuO microspheres as the anode material for LIBs demonstrate a high reversible capacity of 626 mA h g−1 at 100 mA g−1 with a capacity retention of ∼93% over 200 cycles, a stable specific capacity of 553 mA h g−1 after 600 cycles even at a high current density of 1000 mA g−1, and superior rate capability with a high discharge capacity of 262 mA hg−1 at 5000 mA g−1. Therefore, this study innovatively constructs carbon microspheres with a hierarchical structure accompanied by self-growing CuO nanosheets as the anode material for LIBs, which may provide a new idea for the rational design of 3D carbon/metal oxide hybrids.

The healing process of infected skin lesions is often delayed by many factors including bacterial infection, excessive accumulation of wound exudate, poor local perfusion, and low cell recruitment. Development of wound dressing for efficient wound management and promotion of wound healing is a great challenge. Herein, we constructed a Janus nanofiber dressing with the comprehensive capacities of bacterial killing, piezoelectrical stimulation for promoting fibroblast migration, and wound exudate removal via unidirectional liquid delivery. The rationally designed Janus nanofibrous dressing with ultrathin, flexible, breathable, and piezoelectric characteristics is fabricated via the facile layer-by-layer electrostatic spinning technology. The hydrophilic layer of the dressing is composed of randomly arranged polycaprolactone/gelatin (PCL/Gel) nanofibers, while the hydrophobic layer consists of well-aligned Ag nanoparticles (Ag NPs)-doped piezoelectric polyvinylidene fluoride (PVDF/Ag) nanofibers. The in vitro and in vivo experimental results demonstrate that the Janus dressing can not only drain excess wound exudate out of the wound unidirectionally and kill local bacteria, but also generate dynamic piezopotential under normal body motions to promote fibroblast proliferation and migration, collagen deposition, angiogenesis, and re-epithelialization, which accelerates rapid wound healing on mice. The smart Janus dressing will provide a new approach for acceleration of wound healing and wound management.

Carbon materials are commonly used in the solar steam generation because they can absorb broadband light and generate heat effectively. However, conventional carbon with a smooth surface is limited by a moderate reflection of approximately 10%, causing significant reflective energy loss. Thus, we proposed a nanoscale multiple interface strategy to boost the intrinsic light absorption of carbon nanofibers (CNFs) for more efficient solar-driven water purification. The multiple interfaces were constructed by introducing hierarchical nanopores in CNFs (HPCNFs) through a facile sacrificial framework method. Owing to the high surface roughness and abundant internal air-dielectric interfaces derived from the hierarchical pores, the HPCNFs show significant improvement in broadband light (300–2500 nm) absorption up to 97.62%, which enables high solar-vapor conversion efficiency of 96.13% and evaporation rate of 1.78 kg m−2 h−1 under one sun illumination, surpassing majority of the related carbon materials. When used for solar steam desalination, the HPCNF film demonstrates high rejection of ions (< 0.05 mg L−1 salt ions) and produces freshwater from the lake at a rate of 11.18 kg m−2 per day, adequate to satisfy the daily needs of 4–5 individuals. This work provides a facile strategy for designing efficient carbon-based solar steam generation materials.

High-entropy alloys (HEAs) are attracting considerable attention in the field of electrocatalysis. In many cases, HEAs exhibit excellent activity and selectivity toward several catalytic reactions, which is often attributed to their four “core effects”: the high entropy effect, the lattice distortion effect, the sluggish diffusion effect and the cocktail effect. However, the understanding and rational design of HEA electrocatalysts lack a systematic summarization. In this review, a systematic summary of HEA electrocatalysts’ characteristics and applications, as well as a clarification of their design principles, is provided, which has guiding importance for HEA development. First, the reason why HEAs could be excellent electrocatalysts is illustrated from several aspects, including their outstanding mechanical properties, optimized structure and composition, abundant active sites with high intrinsic activity, and ultrahigh stability. To deepen the understanding of HEA electrocatalysts, the rational design of HEAs is carefully demonstrated in terms of design principles, element selection, and the use of computation methods for property prediction. Second, the latest advances in HEA electrocatalysts in the fields of water electrolysis, fuel cells, small organic molecule electrochemical oxidation, and carbon- and nitrogen-based conversion are discussed in detail. Importantly, theoretical calculations and in situ characterizations for an understanding of HEAs’ mechanism are carefully illustrated. Finally, we propose the challenges and perspectives in the future design and application of HEA electrocatalysts.

Over the past decade, all-inorganic metal halide perovskites (MHPs, CsPbX3: X = Cl, Br, I) have been widely investigated as promising materials for optoelectronic devices such as solar cells and light-emitting diodes. MHPs are defect-tolerant, which allows tuning of their bandgap without altering their photophysical properties. From a fundamental point of view, MHPs are excellent candidates for photocatalytic reactions due to their light-harvesting capability, high photogenerated charge-carrier mobility, long diffusion lengths, and tunable bandgap energy. In this review, we provide an overview of various MHP engineering strategies (e.g., surface, morphological, and structural modifications, heterojunction coupling, and encapsulation) which are directly linked to the charge-carrier mobility and lifetimes, and then to the photo-catalytic efficiency. Specifically, we outline different synthetic approaches resulting in surface and morphological modifications, anion/cation substitution, metallic doping, coupling, and encapsulation that tremendously influence MHPs’ stability, optical properties, and charge-carrier dynamics at variable time scales (from fs to µs). We also provide an in-depth evaluation of the MHPs for variable photoredox reactions, discussing how the optical and electronic properties help to improve their stability and efficiency.

Electrochemical CO2 reduction (CO2RR) is a promising technology to mitigate the greenhouse effect and convert CO2 to value-added chemicals. Yet, achieving high catalytic activity, selectivity, and stability for target products is still a big challenge. Herein, interstitially Sn-doped Bi (Snx-Bi, x is the atomic ratio of Sn to Bi, x = 1/2, 1/16, 1/24 or 1/40) nanowire bundles (NBs) are prepared by reducing Sn-doped Bi2S3. Notably, Sn1/24-Bi NBs exhibit ultrahigh formate selectivity over a broad potential window of 1400 mV (Faradaic efficiency over 90% from −0.5 to −1.9 V vs. reversible hydrogen electrode (RHE)) with an industry-compatible current density of −319 mA cm−2 at −1.9 V vs. RHE. Moreover, superior long-term stability for more than 84 h at ∼−200 mA cm−2 is realized. Experimental results and density functional theory (DFT) calculations reveal that interstitially doped Sn optimizes the adsorption affinity of *OCHO intermediate and reduces the electron transfer energy barrier of bismuth catalyst, resulting in the remarkable CO2RR performance. This study provides valuable inspiration for the design of doped electrocatalysts with enhanced catalytic activity, selectivity, and durability for electrochemical CO2-to-formate conversion.

Antimony selenosulfide (Sb2(S,Se)3) is a promising photovoltaic material because of its high chemical stability, optimal optoelectronic properties, and low-cost advantages. However, finding suitable material processing approaches to obtain elemental controlled Sb2(S,Se)3 films with suppressed deep-level defects poses fundamental demands and challenges to developing this emerging solar technology. Here, we developed a robust method for tailoring the composition of the film through controlling the anion elements. The films were prepared by evaporating the presintered Sb2(S,Se)3 alloy compound via a single-source thermal evaporation process. A quasi-precise estimate of single-phase Sb2(S,Se)3 films was made by sintering Sb, S, and Se elemental precursors and adjusting the anion molar ratio in the prefabricated Sb2(S,Se)3 alloy compound, and the elemental ratio of the precursor alloy compound was maintained in the as-obtained Sb2(S,Se)3 films. A highly efficient Sb2(S,Se)3 solar cell with a power conversion efficiency of 8.25% was achieved by introducing low-cost CuPc-doped P3HT as a hole-transporting layer. Here, we demonstrate the dependence of deep-level defects and oriented crystal growth on the S/Se atomic ratios and show how tunability can be used to improve carrier transport for photovoltaic energy conversion. Our study presents a novel approach to fabricating metal chalcogenide semiconducting films and improving the performance of Sb2(S,Se)3 solar cells.

The enthalpy relaxation and recovery processes of an Au-based metallic glass model were studied using high-precision nanocalorimetry. The glassy states after isothermal and isochronal annealing were compared, and it was revealed that the relaxation peaks for slightly and isochronally annealed glasses were narrower compared with slightly and isothermally annealed glasses, although they have the same enthalpy. This reveals a typical thermal history-dependent behavior. Interestingly, when the glasses were heavily annealed, the relaxation peaks of both isothermally and isochronally annealed glasses became identical, denoting no relation to thermal histories. Further relaxation kinetics studies revealed that dependence on thermal paths occurred in the β-relaxation stage, while the glassy states became identical when the α-relaxation stage was reached regardless of the thermal paths. This is attributed to the ergodic characteristic of cooperative atomic motions during the α relaxation. The difference between β and α relaxations in dependence on annealing paths is helpful for precisely controlling the glass properties.

Solar-driven water evaporation is a sustainable solution for hypersaline water treatment, but salt accumulation on the evaporator surface seriously threatens the evaporation system longevity. Despite previous great efforts, critical challenges remain in preventing salt accumulation while maintaining a high evaporation rate. Herein, a salt-resistant three-dimensional carbon nanofiber/graphene oxide composite aerogel (CNF/GOA) with a high evaporation rate was designed. The introduction of GO dramatically enhanced the mechanical property of CNF/GOA and constructed abundant hierarchical interconnected channels for rapid water replenishment and salt diffusion. By suppressing heat conduction loss to bulk water and decreasing water evaporation enthalpy based on regulating the immersion depth and pore structure of CNF/GOA, an evaporation rate of 3.47 kg m−2 h−1 (3.5 wt% NaCl solution) was achieved under 1 sun irradiation (1 kW m−2). More importantly, hypersaline water evaporation (24.0 wt% NaCl brine and industrial hypersaline wastewater) without salt crystallization was achieved. The results of 24-h continuous testing and 10 cycles of 8-h testing proved that CNF/GOA possessed outstanding long-term stability. The outdoor evaporation experiment of the concentrated desulfurization wastewater exhibited a high evaporation rate (23.26 kg m−2 d−1, 7:00–17:00), indicating CNF/GOA had great practical application prospect. This work may offer a fascinating avenue towards practical hypersaline wastewater treatment.