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The creation of metal-metal oxide interfaces is an important approach to fine-tuning catalyst properties through strong interfacial interactions. This article presents the work on developing interfaces between Pt and CeOx that improve Pt surface energetics for the hydrogen evolution reaction (HER) within an alkaline electrolyte. The Pt-CeOx interfaces are formed by depositing size-controlled Pt nanoparticles onto a carbon support already coated with ultrathin CeOx nanosheets. This interface structure facilitates substantial electron transfer from Pt to CeOx, resulting in decreased hydrogen binding energies on Pt surfaces, and water dissociation for the HER, as predicted by the density functional theory (DFT) calculations. Electrochemical testing indicates that both Pt specific activity and mass activity are improved by a factor of 2 to 3 following the formation of Pt-CeOx interfaces. This study underscores the significance and potential of harnessing robust interfacial effects to enhance electrocatalytic reactions.

The depletion of conventional fossil fuels necessitates the development of sustainable energy alternatives, with electrochemical water splitting for hydrogen (H 2) production being a promising solution. However, large-scale hydrogen generation is hindered by the scarcity of cost-effective electrocatalysts to replace noble metals such as Pt and RuO 2 in the Oxygen Evolution Reaction (OER) and Hydrogen Evolution Reaction (HER). In this study, we report the synthesis of CuCr 2-x In x Se 4 (x = 0, 0.2, 0.4) using a dual approach combining the Bridgman-Stockbarger method and ball milling. Among the synthesized materials, CuCr 1.8 In 0.2 Se 4 demonstrates outstanding HER activity in 1.0 M KOH, achieving a potential of −0.16 V vs. RHE at a current density of 10 mA cm−2. Moreover, the material shows remarkable durability during a three-electrode accelerated degradation test in an alkaline medium, maintaining its performance over 24 h at a constant current density of −200 mA cm−2, with a stable potential of −0.57 V vs. RHE. Additionally, CuCr 1.8 In 0.2 Se 4 was tested in a two-electrode configuration alongside CoFe LDH, achieving a benchmark of 1.7 V for overall water splitting. It sustained a current density of 400 mA cm−2 for 24 h in an accelerated degradation test, exhibiting a minimal loss of 0.1 V after the testing period. These results highlight CuCr 1.8 In 0.2 Se 4 as a promising non-noble metal catalyst for HER, demonstrating its potential to reduce reliance on noble materials for large-scale hydrogen production. [Display omitted] • CuCr 2-x In x Se 4 was synthesized using Bridgman-Stockbarger and ball milling techniques. • CuCr 1.8 In 0.2 Se 4 showed excellent HER activity, of −0.16 V vs RHE for 10 mAcm−2. • In a two-electrode setup, it required 1.7 V and to achieve 400 mAcm−2 for 24 h. [ABSTRACT FROM AUTHOR]

The layered N-doped tungsten carbide (WC) with enhanced electrical conductivity was designed and fabricated via a facile molten-salt-chemistry-assisted strategy as electrocatalytic material for efficient hydrogen evolution reaction (HER), which is a prospective and feasible approach for green and carbon-neutral hydrogen energy storage. The layered WC structure was in situ formed via carbonization procedure utilizing the as-prepared WO 3 microspheres as substrates. The microstructure, physicochemical properties, and electrocatalytic HER performance of WC catalysts can be regulated by the treatment temperature ranging from 700 to 1000 °C during the molten-salt-chemistry-assisted processes with NaCl/KCl mixture as the molten salt. The engineered WC/C-900 catalyst with optimized components of W, C, and N elements, synergistic effect, and enhanced electrical conductivity provides high HER performance with an overpotential of 188 mV (684 mV of WO 3) and long-term 28 h stability at 10 mA cm−2 in acidic medium. Additionally, in-depth insights into the catalyst microstructure, temperature-dependent phase transition, surface/interface properties, structure-activity relationships, and HER mechanism of the versatile material on the basis of theoretical calculation and experimental discovery are also investigated. • The layered WC is fabricated by a facile molten-salt-chemistry-assisted strategy. • Carbonization temperatures can regulate physicochemical properties of WC catalysts. • WC/C-900 displays enhanced electrical conductivity and synergistic effect. • The WC/C-900 catalyst exhibits high HER performance and long-term stability. [ABSTRACT FROM AUTHOR]

Hydrogen holds the promise of replacing fossil fuels and offers a sustainable pathway for energy generation. However, the large-scale production of hydrogen via the environment friendly electrocatalytic process relies heavily on the performance of electrocatalysts. In this study, we investigate the electrocatalytic performance of graphene nanosheets (GNS), molybdenum disulfide (MoS 2), ruthenium dioxide (RuO 2), and their composites for hydrogen evolution reaction (HER), a novel combination that has not been explored in previous literature. We synthesize the materials using Liquid Phase Exfoliation at 500 and 1000 RPMs for GNS and MoS 2 and via hydrothermal methods for RuO 2 nanosheets and nanoparticles, aiming to exploit synergistic effects for enhanced activity and stability. The synthesized GNS-1000/MoS 2 -1000/RuO 2 -NSs composite demonstrates promising HER results, showcasing a low overpotential of 63 mV and a reduced Tafel slope of 59 mV/dec. This improvement indicates enhanced electron transfer, improved active site dispersion, and increased surface area due to the synergistic effects, which also aids in long-term electrochemical stability. Our study underlines the potential of GNS/MoS 2 /RuO 2 composites, particularly the GNS-1000/MoS 2 -1000/RuO 2 -NSs, in transforming hydrogen production methods and promoting efficient, sustainable energy solutions. The implications of our findings extend the boundaries of materials engineering, edging us closer to a sustainable energy future. • Novel GNS/MoS 2 /RuO 2 catalyst enhances HER with low overpotential and Tafel slope. • Synergistic effects of GNS, MoS 2 , and RuO 2 boost electron transfer in HER. • Cost-effective alternative to platinum catalysts developed for hydrogen production. • Optimized synthesis improves catalytic activity and stability in HER. • Composite catalyst offers potential for sustainable energy applications. [ABSTRACT FROM AUTHOR]

Cost-effective, active, and durable electrodes are required for the development of the efficient alkaline water electrolysis towards green hydrogen production. Here, we report successful fabrication of such electrodes by means of robust radio frequency magnetron sputtering that produces uniform, crystalline, and phase pure catalytic iridium thin films over nickel foam current collectors. The effect of working pressure of argon gas during sputtering on the physicochemical and electrochemical properties of the as-fabricated electrodes has been investigated. Specifically, it has been established that the employment of working pressure of 3 Pa afforded the electrodes with the lowest mass loading of precious iridium metal (≈0.32%), but exhibiting the best alkaline water electrolysis performance. The electrodes demonstrated favourable overpotentials of 14 mV and 318 mV at current densities of ±10 mA/cm2 toward hydrogen (HER) and oxygen (OER) evolution reactions, respectively. Furthermore, as a cathode and an anode for overall water splitting (OWS) in alkaline electrolyte, the electrode exhibited the cell voltage of 1.57 V at 10 mA/cm2 and stably performed electrolysis at different applied current densities. The electrochemical performance of the electrodes has been corroborated by work function measurements using Kelvin probe force microscopy. • Phase pure Ir thin films on nickel foam were fabricated by RF magnetron sputtering. • The effect of the working gas pressure on HER and OER performance was observed. • Bifunctional NiF@Ir-3 electrode can stably sustain OWS at several current densities. • Work function measurements prove to be a useful tool to validate electrochemical results. [ABSTRACT FROM AUTHOR]

The undesirable intrinsic activity of tungsten oxides derived from poor conductivity and adverse hydrogen absorption energy is insufficient for their practical application. Herein, the tungsten oxides with adjustable oxygen vacancies were synthesized by a facile pyrolysis of ammonium paratungstate hydrate in controllable atmospheres. The structural characterizations confirmed that oxygen vacancies and crystalline phases in tungsten oxides depend on the pyrolysis atmosphere. The electrochemical test indicated a strong dependence between catalytic activity and oxygen vacancies in tungsten oxides. Combining experimental results and density functional theory calculations verified that introducing oxygen vacancies into tungsten oxides effectively modulates the surface electronic structure. The enhanced electronic conductivity by reducing band gap accelerates the electron transfer from catalysts into the reactive species. The optimized hydrogen adsorption energy by electron migration from O into W promotes the activation of reactive species at W sites and the desorption from O sites, thereby accelerating the reaction kinetics. The regulated oxygen vacancies in tungsten oxides was availably achieved by controlling the annealing atmospheres for ammonium paratungstate hydrate. The as-prepared tungsten oxide catalysts exhibit a strong dependence between oxygen vacancies contents and catalytic activity for hydrogen evolution reaction. The experimental observations and theoretical calculations confirm that oxygen vacancies introduced into tungsten oxides can enhance the electronic conductivity and optimize the hydrogen adsorption energy to remarkably improve the catalytic activity. [Display omitted] • Oxygen vacancies in WO 3 were regulated by controlling annealing atmospheres. • WO 3 exhibits a strong dependence between oxygen vacancies and catalytic activity. • Introducing oxygen vacancies reduces band gap to improve electronic conductivity. • Oxygen vacancies optimize hydrogen adsorption energy on tungsten oxides. [ABSTRACT FROM AUTHOR]

In this study, Co-bearing Metal-Organic Frameworks (MOFs) are grown via a facile solvothermal process on the surface of two kinds of conductive substrates – titanium dioxide nanotubes (TiO 2 NT) and fluorine-doped tin oxide (FTO) glass and tested as electrodes in the electrochemical hydrogen evolution reaction (HER). The materials derived from three organic linkers - terephthalic acid (Co-BDC), 2-aminoterephthalic acid (Co-BDCNH 2), and trimesic acid (Co-BTC) are characterized by FTIR, Raman, XRD, SEM-EDS, BET, and XPS. Among the layers on FTO without post-synthesis treatment, Co-BTC shows the highest activity (overpotential of HER 1.72 V vs. Ag/AgCl/KCl). The effects of substrate change on TiO 2 NT and annealing of Co-BTC layers in air and argon on their electrocatalytic properties are also studied. Using TiO 2 nanotubes as a substrate and annealing the material in air results in a reduction of the hydrogen evolution overpotential to 1.44 V vs. Ag/AgCl/KCl and a significant reduction in the exchange current density. • Co-based MOFs were successfully fabricated on FTO and TiO 2 NT. • Electrochemical activity depended more on organic linker than substrate type. • Annealing of Co-BTC materials improves catalytic activity in HER. [ABSTRACT FROM AUTHOR]

Urea-assisted water electrolysis is a promising strategy for the high-efficiency hydrogen production due to the more favorable anodic thermodynamic potential of urea oxidation reaction (UOR) than that of oxygen evolution reaction (OER). However, the kinetics of UOR is sluggish and thereby the fabrication of UOR catalyst which also possesses cathodic hydrogen evolution reaction (HER) catalytic performance is ascribed to be the paramount bottleneck due to the hard simultaneous satisfaction between UOR and HER performance metrics. Herein, a hierarchical amorphous-crystalline heterogeneous NiCoS x nanosheet with rich lattice defects grown on nickel foam (NiCoS x /NF) catalyst was proposed via scalable solvothermal method for overall urea-assisted water electrolysis. The NiCoS x /NF only needs an ultralow potential of 1.36 V to drive 100 mA cm−2 for UOR, exceeding that of OER for 220 mV, and an overpotential of 183 mV to obtain 100 mA cm−2 for HER. More importantly, the urea electrolyzer assembled with NiCoS x /NF as both cathode and anode could achieve 10, 100, and 500 mA cm−2 at battery voltages of 1.41 V, 1.55 V, and 1.75 V, respectively, with continuous working for 60 h. Experimental and density functional theory calculations reveal that the strong electronic interactions caused by heterojunctions and lattice defects exposed on the well-accessible NF surface result in the increased proportions of Ni3+ active sites and enhanced conductivity, which should be responsible for the superior UOR and HER performance. • NiCoS x nanosheets with Co 3 S 4 /Ni 3 S 2 /NiCo heterojunctions and rich defects grew on nickel foam. • NiCoS x /NF-based urea-assisted water splitting device show prominent catalytic activity and stability. • Heterojunctions and defects should be responsible for the superior performance of NiCoS x /NF. [ABSTRACT FROM AUTHOR]

Efficient hydrogen production via anion exchange membrane water electrolysis depends on hydrogen evolution reaction (HER) electrocatalysts with excellent kinetics in alkaline electrolytes. Amorphous alloys offer enhanced electrochemical properties and improved corrosion resistance, making them attractive candidates. Among these, the bimetallic nickel molybdenum (NiMo) alloy stands out as one of the most active transition-metal-based HER electrocatalysts, available in both amorphous and crystalline forms. This study investigates the influence of thermal annealing temperature in a reducing environment on the phase change and electrochemical properties of hydrothermally grown 1-dimensional (1D) NiMo nanorods. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) revealed that lower annealing temperatures resulted in a mixed amorphous and crystalline phase of NiMo, while higher temperatures led to increased crystallinity and a decrease in the amorphous fraction. Electrochemical analysis indicates that the amorphous NiMo annealed at 400 °C exhibits overpotentials as low as 31 and 115 mV at 10 and 100 mA cm−2, respectively, outperforming several similar electrocatalysts reported in the literature. This enhanced activity is attributed to improved electron and mass transport, along with increased exposure of active sites in the amorphous phase. Thus, there is a clear relationship between annealing conditions and the formation of amorphous NiMo, which exhibits excellent HER properties and durability. • Amorphous-crystalline NiMo alloy enhances HER kinetics in alkaline electrolytes. • Lower annealing temperatures yield amorphous characteristics of NiMo with superior HER activity. • NiMo annealed at 400 °C achieves 31 mV overpotential at 10 mA cm−2. • Amorphous state boosts electron transport and active site exposure. • Tailored annealing links to NiMo's excellent HER properties and durability. [ABSTRACT FROM AUTHOR]

Alkaline water electrolysis is the promising technical pathway of large‐scale green hydrogen production. However, its hydrogen evolution reaction (HER) is hindered by the alkaline environment, leading to slow H2O splitting kinetics, especially for NiMoCu alloy catalysts which are considered potential alkaline HER catalysts. In this work, the Ru‐substrate modified NiMoCu20 porous electrode is designed by a continuous multistep electrodeposition method. It shows the good alkaline HER performance at the high current density of 1000 mA cm−2, which is attributed to the synergistic charge‐reconfiguration effects between Ru‐substrate and NiMoCu alloy by density functional theory (DFT) calculations and in situ Raman spectra analysis. It indicates that the Ru‐substrate is capable of encouraging H‐OH* bond breakage and optimizing transition‐state H* adsorption. Further, the overall water electrolysis results of the alkaline water electrolysis cell (30 wt% KOH) at 70 °C show that it has good performance at the large current density of 1000 mA cm−2 with 2.05 V and good stability at 600 mA cm−2 up to 500 h. It provides the possibility of designing the high‐performance HER electrode from the view of industrial applications. [ABSTRACT FROM AUTHOR]

The incorporation of defects and cocatalysts is known to be effective in improving photocatalytic activity, yet their coupled contribution to the photocatalytic hydrogen evolution process has not been well‐explored. In this study, We demonstrate that the incorporation of S vacancies and NiSe can contribute to the improvement of charge separation efficiency via the formation of a strong electric field within the bulk ZnIn2S4 (ZIS) and on its surface. More importantly, We also demonstrate that the synergy of S vacancies and NiSe benefits the overall hydrogen evolution activity by facilitating the H2O adsorption and dissociation process. This is particularly important for hydrogen evolution taking place under alkaline conditions where the proton concentration is low, allowing ZISv‐NiSe (containing abundant S vacancies) to outperform ZIS‐NiSe under alkaline conditions. In contrast, under acid conditions, since there are already sufficient amounts of protons available for reaction, the hydrogen evolution activity became governed by the hydrogen adsorption/desorption process rather than the H2O dissociation process. This leads to ZIS‐NiSe exhibiting higher activity than ZISv‐NiSe due to its more favorable hydrogen adsorption energy. The findings thus provide insights into how defect and cocatalyst modification strategies can be tailor‐made to improve hydrogen evolution activity under different pH conditions. [ABSTRACT FROM AUTHOR]

The design of high-efficiency and cost-effective electrocatalysts for water splitting has recently received much attention. Herein, a self-supported Fe-doped NiMo/NiCo bifunctional electrocatalyst was synthesized using hydrothermal method on nickel foam (NF) to enhance both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). SEM observations revealed NiCo microspheres arranged in a flower-like structure, with Fe-doped NiMo rods decorating the surface. This electrocatalyst demonstrated impressive HER performance, requiring a low overpotential of 63 mV, versus reversible hydrogen electrode (RHE), at a cathodic current density of −10 mA/cm2, and a small charge transfer resistance (R ct) of 2.43 Ω at −200 mV (RHE). For OER, the synthesized electrocatalyst revealed excellent activity, with a low overpotential of 151 mV (RHE) to afford an anodic current density of 10 mA/cm2 and a small R ct of 0.43 Ω at 300 mV (RHE). Meanwhile, the Fe-doped NiMo/NiCo@NF electrocatalyst in a two-electrode configuration needed only a cell voltage of 1.53 V to deliver a current density of 10 mA/cm2. Overall, this work disclosed that the combination of NiCo and NiMoFe results in the synthesis of a heterogeneous electrocatalyst that offers high efficiency for water splitting and maintains good stability over 10 h. [Display omitted] • A hierarchical Fe-doped NiMo/NiCo@NF electrocatalyst, was synthesized by the hydrothermal method. • Large specific surface area, abundant active sites, and synergistic effects between constituents enhanced both HER and OER activity. • This electrocatalyst displayed appropriate structural and performance stability for10 h. [ABSTRACT FROM AUTHOR]

The increasing demand for clean and renewable energy underscores the importance of hydrogen energy, with electrocatalytic water splitting being an efficient method for green hydrogen production. Platinum, while an excellent catalyst for hydrogen evolution reactions (HER), is hindered by high cost and scarcity. This study explores non-precious alternatives, focusing on MoS 2 due to its "platinum-like behavior." The 1T-2H MoS 2 loaded on N-doped carbon (NC) catalysts (1T-2H MoS 2 @NC) were synthesized through a one-step pyrolysis of melamine and ammonium thiomolybdate. Comprehensive analysis revealed that the 2H phase formed at 700 °C, transitioning to a biphasic 1T-2H composition at higher temperatures. The catalyst synthesized at 800 °C with a 1:8 reactant ratio demonstrated exceptional HER performance, with an overpotential of 175 mV at 10 mA cm−2 and a Tafel slope of 92.37 mV dec−1. This study highlights the potential of 1T-2H MoS 2 @NC as a cost-effective and efficient catalyst for sustainable hydrogen production. [Display omitted] • The one-step pyrolysis method was used to synthesize 1T-2H MoS 2 @NC- n - T catalyst. • With a 175 mV overpotential at 10 mA cm−2 and a 92.37 mV dec−1 Tafel slope, the catalyst excels in acidic media. • In the catalyst, the 1T phase and the 2H phase MoS 2 coexist. • MoS 2 and NC are tightly bonded to improve the conductivity and stability of the catalyst. [ABSTRACT FROM AUTHOR]

Electrodes modified with functional catalysts overcome the energy barriers of green hydrogen production through the electrolysis of aqueous media. Noble and non-noble metals, their alloys and other derivatives, carbonaceous compounds and polymers have been widely explored efficiently as catalysts and/or supports in enhancing the electrocatalytic hydrogen evolution reaction (HER). Although the efficiency of conductive polymer as a catalyst as well as conductive support are critically evaluated extensively, these materials and their electrocatalytic characteristics didn't get reasonable attention and exploration in electrocatalysis, particularly in HER. Without critical scientific challenges, the limited exploration in HER might be due to the lack of comprehensive data on the properties of conductive polymers and their role in HER. In this scenario, this review unveils the scope of most of the conductive polymers belong to different classes and their scientific details towards HER. Discussion on various kinds of conductive polymers (both metal and non-metal based), their features such as intrinsic catalytic efficacy, electrochemical characteristics, functional moieties and their role on catalysis and support. Various modification techniques for enhancing the intrinsic activity and the number of active catalytic sites, mechanism of interaction of polymer catalyst with reactant and intermediates for hydrogen evolution are detailed respective to instances. Characteristics of epoxy polymers are analyzed in detail with respect to the peculiarities of an HER electrocatalysts, which is never debated before. The content in this work also summarized the challenges and future directions of polymer based HER electrocatalysis. The review inculcates the role of polymer and divulges new direction to polymer based electrocatalytic HER. • Conductive polymers in hydrogen evolution. • Metallic, Non-metallic, Organic, Inorganic & Epoxy polymers are studied. • Role as catalyst and conductive support in electrolysis. • Mechanism of CP assisted water splitting. • Advanced strategies for enhancing the intrinsic activity. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries have become a promising energy storage battery due to high theoretical specific capacity, abundant zinc resources and low cost. However, zinc dendrite growth and hydrogen evolution reaction limit their application. This study aims to improve the cycling performance and stability of aqueous zinc‐ion batteries by improving the gel electrolyte. Polyacrylamide (PAM) is selected as the base material of the gel electrolyte, which has good stability and safety, but the water retention capacity, Zn2+ migration number, and ionic conductivity of PAM are low, which affects the long‐term stability of the battery. In response to these problems, we optimized PAM by chemical cross‐linking method, and formed an enhanced PAM gel by adding disodium citrate dihydrate (SC). Experimental results show that the introduction of an appropriate amount of SC in the enhanced PAM gel electrolyte can significantly improve its electrochemical performance. The zinc‐ion symmetric battery achieved a stable cycle of more than 2100 hours at a current density of 0.5 mA cm−2, which is mainly attributed to the inhibitory effect of the enhanced PAM gel on zinc dendrite growth and hydrogen evolution reaction. This study provides a new direction for the development and application of flexible zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Here, integrated functional components into a hybrid heterostructure via highly stabilized network‐like interconnected electronic nanoarchitecture of 1D N‐doped holey‐carbon nanotube (NHCNT) with 2D nickel─metal–organic framework (Ni─MOF) nanosheets are developed as high‐performance electrocatalyst for overall water splitting. The NHCNT promoting electron transport pathways in electrocatalyst, and formation of holes in nanotubes further enables excellent diffusion of ions for promoting the overall reaction rate. An excellent combination of 1D/2D structure of NHCNT/Ni─MOF‐4 electrocatalyst exhibits excellent oxygen evolution reaction (η10 = 207.8 mV, and Tafel = 62.6 mV dec−1) and reasonable hydrogen evolution reaction (η10 = 159.8 mV, and Tafel = 107.69 mV dec−1) activity with consistent and stable performance in a 1 m KOH. The highly interconnected network structure contains Ni2+ and Ni3+ species in the NHCNT/Ni─MOF‐4 electrocatalyst, which possesses high specific surface area (SSA) (235.53 m2 g−1), electrochemically active surface area (ECSA) (796.2 cm2), mass activity (4.76 mA mg−1), and turnover frequency (3.99 × 10−2 s−1), which provide remarkable electrocatalytic performance via generating synergy between the NHCNT and Ni─MOF. For overall water splitting, NHCNT/Ni─MOF‐4 attains a low cell voltage (1.77 V@10 mA cm−2). [ABSTRACT FROM AUTHOR]

The commercialization of zinc metal batteries (ZMBs) for large‐scale energy storage is hindered by challenges such as dendrite formation, the hydrogen evolution reaction (HER), and passivation/corrosion, which lead to poor stability of zinc metal anodes. HER is a primary contributor to this instability, and despite efforts to enhance ZMB cyclability, a significant knowledge gap remains regarding the origin of HER in these systems. Prior works, based primarily on theoretical calculations with minimal experimental support, suggest that HER originates from Zn2⁺‐solvated water. For the first time, by employing scanning electrochemical microscopy (SECM), and electrochemical mass spectrometry (ECMS), in real‐time the inherently intertwined nature of Zn electrodeposition and H₂ liberation is revealed, both exhibiting the same onset potential in voltammetry. The findings show that water molecules surrounding Zn2⁺ ions undergo reduction simultaneously during Zn2⁺ deposition. Additionally, ECMS conducted under chronopotentiometric/galvanostatic conditions at battery‐relevant current densities elucidates why elevated electrolyte concentrations enhance the prolonged cyclability of ZMBs. Understanding the origin of HER opens avenues for developing high‐performance, reliable aqueous ZMBs, addressing key challenges in their commercialization and advancing their technological capabilities. [ABSTRACT FROM AUTHOR]

Zn metal anode is desired for aqueous batteries due to its high capacity and low redox potential. However, uneven Zn deposition and hydrogen evolution reaction (HER) have hindered the electrochemical reversibility and stability. Herein, an artificial solid electrolyte interphase (SEI) composed of metal center incorporated siloxane coupling with fluoride is in situ generated on Zn surface by a facile “etching–coating” process. This SZ‐SEI provides interaction sites with Zn2+, which helps with its desolvation at the interface and enlarges the transference number. Uniform Zn deposition underneath the layer is thus realized. Meanwhile, the SZ‐component hinders the adsorption of hydrogen atom and effectively suppresses HER. Thanks to the above effects, the cycle life of symmtric cells with SZ‐Zn electrodes extends to 2200 and 1400 h at the current densities of 10 and 20 mA cm−2, respectively. The coulombic efficiency of Zn plating/stripping also reaches 99.8% for 3800 cycles. In addition, the SZ‐Zn anode enables better rate capability and cycling stability of full cells. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A novel electrocatalyst, Ni‐Co/β‐Mo2C@C, was rationally designed to enhance the efficiency of the hydrogen evolution reaction (HER) in this work. Assembled with two‐dimensional Ni‐Co nanosheets onto Mo2C nanorods coated with a thin carbon shell, the catalyst demonstrates remarkable performance, including low overpotential (η10 = 57 mV) and reduced Tafel slope (63 mV·dec–1) in 0.5 mol·L–1 H2SO4 electrolyte. This innovative design strategy provides abundant active sites and efficient electron/ion transport pathways, effectively shortening reactant diffusion distances and enhancing electrocatalytic activity. Additionally, the carbon shell coating protects the catalyst from etching and agglomeration, ensuring its durability. This work presents a promising approach for engineering highly efficient metal carbide‐based HER catalysts through tailored composition and nanostructure design. [ABSTRACT FROM AUTHOR]

[Display omitted] Exploiting highly efficient, cost-effective and stable electrocatalysts is key to decreasing hydrogen evolution reaction (HER) kinetics energy barrier. Herein, the alkaline HER kinetics energy barrier can greatly reduce by the joint strategies of the cation vacancy and heterostructure engineering, which is seldom explored and remains ambiguous. In this study, an efficient and stable copper foam-supported Cu 3 P-CoP heterostructure electrocatalyst with cation vacancy defects (defined as Cu 3 P-CoP-V Al /CF) was designed for HER via the successive coprecipitation, electrodeposition, alkali etching and phosphorization treatments. As anticipated, the as-obtained Cu 3 P-CoP-V Al /CF electrocatalyst reveals a remarkable catalytic activity for HER with a low overpotential of 205 mV at a current density of 100 mA·cm−2, a high turnover frequency value of 1.05 s−1 at an overpotential of 200 mV and a small apparent activation energy (E a) of 9 kJ·mol−1, while shows superior long-term stability at large current densities of 100 and 240 mA·cm−2. Systematic experiment and characterization data demonstrate that the formed cation vacancy could optimize the E a , leading to the decrease of the kinetic barriers of Cu 3 P-CoP/CF heterostructure, as well as the established heterogeneous interface induced a synergistic effect between biphasic components on boosting the kinetics toward HER. The results of density functional theory disclose that the synergistic effect of Cu 3 P-CoP heterostructure could decrease the energy barrier and optimize Gibbs free energy of hydrogen adsorption, resulting in the enhancement of intrinsic catalytic activity of Cu 3 P-CoP-V Al /CF. More significantly, the alkali-cell assembled by Cu 3 P-CoP-V Al /CF (cathode) and RuO 2 /CF (anode) behaves outstanding water splitting performance, delivering a current density of 10 mA·cm−2 at a relatively small applied voltage of 1.58 V, along with encouraging long-term durability. In addition, the alkaline Zn-H 2 O battery with Cu 3 P-CoP-V Al /CF as the cathode has been fabricated for the simultaneous generation of electricity and hydrogen, which displays a large power density of up to 4.1 mW·cm−2. The work demonstrates that rational strategy for the design of competent electrocatalysts can effectively accelerate the kinetics of HER, which supplies valuable insights for practical applications in overall water splitting. [ABSTRACT FROM AUTHOR]

A Zn-air battery-driven SOR||HER coupling system based on a trifunctional P-CoMoO 4 /NF catalyst has been developed for self-powered synchronous sulfur recovery and hydrogen production. [Display omitted] • The self-driven SOR/HER hybrid electrolysis system was assembled for the first time. • P-CoMoO 4 /NF electrocatalysts were designed as three-dimensional catalyst for HER, SOR and ORR. • The sulfur-containing waste water can be recycled and H 2 generation occurs spontaneously. • The electrolysis can be realized without external energy consumption. This study introduces a self-driven system that effectively achieves synchronized sulfur recovery and hydrogen production using a Zn-air battery. The system ingeniously integrates the sulfur oxidation reaction (SOR) and the hydrogen evolution reaction (HER) into a single, efficient process. Central to this system is the trifunctional phosphorus-doped cobalt molybdate catalyst (P-CoMoO 4 /NF), which exhibits superior performance in both HER (η j = 100 = 0.13 V) and SOR (η j = 100 = 0.30 V) with remarkable stability (∼360 h), reaching 0.64 V at 100 mA cm−2 for simultaneous sulfur ion degradation and hydrogen production. Through density functional theory simulations and extensive characterizations, it has been shown that phosphorus doping in the cobalt molybdate catalyst facilitates electron redistribution, enhancing the catalyst's conductivity, generating more oxygen vacancies, and promoting improved mass and electron transfer. This modification also lowers the energy barrier for adsorbing reaction intermediates, thus increasing the hydrogen production rate and sulfur oxide conversion in this self-powered system. In summary, this research marks a substantial advancement in the development of trifunctional catalysts and proposes an eco-friendly, cost-effective strategy for integrated reaction systems, paving the way for sustainable energy solutions. [ABSTRACT FROM AUTHOR]

Hydrogen energy, as the most promising new energy for sustainable development, has aroused wide concern of researcher in the field of energy chemical industry. Among the many hydrogen generation approaches, electric water splitting for producing H 2 is considered to be a simple and environmentally friendly method. Transition metal-based catalysts have become an important field in alkaline seawater electrolysis due to their high abundance and superior catalytic performance. Therefore, NiFeS (Ni 3 S 2 @FeS) was in-situ generated on nickel foam through a simple two-step hydrothermal approach in this paper. NiFeS/NF catalysts synthesized by three vulcanization reagents (Na 2 S·9H 2 O, CH 3 CSNH 2 , CH 4 N 2 S) were characterized and compared by a series of electrochemical tests. It is worth noting that for the first time, different vulcanization reagents were used to explore the activity of the same catalyst in seawater splitting and urea splitting. It was found that the NiFeS catalyst synthesized by Na 2 S·9H 2 O (Ni 3 S 2 @FeS-1/NF) had better oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance and good stability in alkaline seawater. The overpotential required for the OER with Ni 3 S 2 @FeS-1/NF electrode in alkaline seawater (1 M KOH + seawater electrolyte) is 290 mV at the 10 mA cm−2, and 92 mV for the hydrogen evolution reaction at the 10 mA cm−2. It is found that the NiFeS catalyst obtained by vulcanization of NiFe-LDH not only has high activity and conductivity, but also can effectively inhibit Cl− corrosion. Ni 3 S 2 @FeS-1/NF catalyst has a unique cluster rosette nanosheet array structure, which can present more catalytic reaction centres, accelerate the electron transfer rate and promote electrochemistry performance. The work proposes a novel way to explore the effect of different synthesis methods of the same composition on the performance of electrolytic seawater. It was found that the NiFeS catalyst synthesized by Na 2 S·9H 2 O (Ni 3 S 2 @FeS-1/NF) had better oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance and good stability in alkaline seawater. [Display omitted] • NiFeS/NF catalysts synthesized by three vulcanization reagents (Na 2 S·9H 2 O, CH 3 CSNH 2 , CH 4 N 2 S) were characterized. • NiFeS catalyst synthesized by Na 2 S·9H 2 O (Ni 3 S 2 @FeS-1/NF) had better OER and HER performance in alkaline seawater. • Ni 3 S 2 @FeS-1/NF catalyst not only has high activity, but also can inhibit Cl− corrosion. [ABSTRACT FROM AUTHOR]

MoS 2 nanosheets were vertically grown in S-doped graphitic carbon nitride (g-C 3 N 4) nanosheets to enhance electrochemical performance. Dicyandiamide was used as a precursor while sodium molybdate and thioacetamide were as additives, and sulfur was introduced into the carbon lattice of thin-layered g-C 3 N 4 by a two-step thermal polymerization. S-g-C 3 N 4 /MoS 2 (SCN/MoS 2) heterojunctions were then created by a solvothermal synthesis. Subsequently, the electrochemical performance of the heterojunctions was explored. The result suggested that the surface of S-g-C 3 N 4 nanosheets load on uniformly arranged layered MoS 2 possession revealed the smallest Tafel slope of 77.2 mV dec−1. After 1000 cycles, no significant change was observed for the linear sweep voltammetry curves. The SCN/MoS 2 heterojunction revealed a specific capacity of 588 F g−1 after being assembled into an asymmetric supercapacitor. Superior thin g-C 3 N 4 nanosheets and constituting a composite with strong interfacial electronic coupling with MoS 2 , doping with heteroatomic elements, and changing the surface structure of g-C 3 N 4 enhanced the charge transfer kinetics and improved the electrochemical performance. • MoS 2 nanosheets were vertically grown on S-doped g-C 3 N 4 nanosheets to get enhanced electrochemical performance. • S in g-C 3 N 4 nanosheets plays an important role for the growth controlling of MoS 2 nanosheets. • S-g-C 3 N 4 /MoS 2 heterojunctions revealed the smallest Tafel slope and also revealed ideal energy storage performance. [ABSTRACT FROM AUTHOR]

In order to replace the Pt catalyst which has several limitations that hampered the corresponding practical applications. A series of mesoporous carbons encapsulating CoP nano-particles and doped with P were prepared by a combination of solvent-evaporation-induced self-assembly (EISA) and carbonization. Phenolic-based resins and diammonium hydrogen phosphate as carbon and phosphorus precursors, respectively. Cobalt chloride hexahydrate (CoCl 2) was used as the cobalt precursor, which was also treated as the porogen. Based on characterization data, the porosity of the final sample depends on the amount of CoCl 2 added. which could further determine the electrocatalytic activity. When evaluated as the electrocatalysts towards hydrogen evolution reaction (HER), the as-received electrocatalysts exhibited outstanding electrocatalytic performance, including low overpotential, small Tafel slope, and good stability. • CoP NPs entrapped, P doped carbons are prepared via combination of EISA and carbonization. • The amounts of CoCl 2 determine the crystalline structures of final products. • Co1.00 PC-900 possesses excellent electrocatalytic performance towards HER. [ABSTRACT FROM AUTHOR]

Recently, there has been growing interest in replacing expensive platinum-based catalysts with cost-effective non-precious metal alternatives for water electrolysis aimed at hydrogen production. This study introduces an innovative, green, and cost-effective strategy for the development of non-precious electrocatalysts by leveraging sodium alginate-mediated ultrasonic exfoliation to produce transition metal dichalcogenide (TMD) nanosheets. These nanosheets are supported on Sonogel-Carbon electrodes (SGC), providing a novel conductive base for HER catalysis. Using a diverse array of TMD materials, including MoS 2 , MoSe 2 , WS 2 , and WSe 2 , we assess their catalytic activity towards HER. The study demonstrates significantly enhanced HER performance through bulk modification of the electrodes with nanocarbon black (SGC-CB). This enhancement is primarily due to the synergistic effects of improved electron transfer and increased active site availability, facilitated by the unique structural properties of the exfoliated TMD nanosheets and the conductive Sonogel-Carbon substrate. Notably, the optimized MoSe 2NS -SGC-CB configuration achieves an exceptional overpotential of 240 mV at a current density of 10 mA/cm2, surpassing conventional bulk catalysts and highlighting the potential of sodium alginate as a viable dispersing agent for the large-scale production of TMD nanosheets. The operational stability and cost-effectiveness of this electrocatalyst, combined with its environmental friendliness, mark a significant step forward in the pursuit of sustainable hydrogen fuel production technologies. [Display omitted] • Achieved TMD nanosheets via rapid, green sodium alginate-assisted ultrasonic LPE. • Sonogel carbon (SGC) outperforms conventional carbon support in HER catalysis. • Bulk-modifying SGC with nanocarbon black (CB) further enhances HER performances. • MoSe 2 NS -SGC-CB shows 240 mV overpotential at 10 mA/cm2 with high stability. [ABSTRACT FROM AUTHOR]

Sugarcane bagasse carbon (SCBC) was synthesized and used to support NiCoP/CoP 2 nanoparticles (NiCoP/CoP 2 -SCBC), and its electrocatalytic performance for the hydrogen evolution reaction (HER) was investigated and compared with that of NiCoP/CoP 2 nanoparticles and NiCoP/CoP 2 nanoparticles supported on carbon black (NiCoP/CoP 2 -C). Impressively, NiCoP/CoP 2 -SCBC shows the best electrocatalytic performance for HER with an over-potential of 159.5 mV at 10 mA cm-2 and a Tafel slope of 67.24 mV dec-1, along with the excellent stability. This outstanding performance is partly attributed to the abundant hydroxyl functional groups in SCBC, which can make the catalyst have better dispersion and a higher proportion of Ni2+. In addition, SCBC can lead to more defects in NiCoP/CoP 2 , and SCBC contains a large number of P elements, which can increase the catalytic active sites and contribute to the fast HER process to some degree. • The NiCoP/CoP 2 -SCBC composite catalyst was prepared by a calcination method. • NiCoP/CoP 2 -SCBC shows superior electrocatalytic activity for HER in acid solution. • The high catalytic activity of NiCoP/CoP 2 -SCBC is due to the abundant –OH in SCBC. • More defects caused by SCBC and its rich P content also contribute to the activity. • NiCoP/CoP 2 -SCBC has excellent long-term stability besides high catalytic activity. [ABSTRACT FROM AUTHOR]

Hydrogen energy is characterized as environmentally friendly and resourceful. The hydrogen evolution reaction (HER) is a crucial process for hydrogen production and is essential for achieving a transition to sustainable and clean energy. In this work, we conducted a systematic investigation into the hydrogen catalytic activity of two-dimensional WSn 2 N 4 materials. The transition metal atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) were substituted at the N and Sn sites in WSn 2 N 4 , respectively. The catalyst's performance was evaluated to verify its catalytic activity for the HER. The results indicate that the Gibbs free energy changes (ΔG H∗) of Ti@W–WSn 2 N 4 , V@W–WSn 2 N 4 , Fe@W–WSn 2 N 4 , Co@W–WSn 2 N 4 , and Ni@W–WSn 2 N 4 are close to zero. Among the structures examined, Ti@W–WSn 2 N 4 exhibited the lowest Gibbs free energy change (ΔG H∗ = −0.01 eV), indicating a high degree of catalytic activity. Through machine learning analysis, key features affecting catalytic activity could be directly identified, and a framework for rapid screening was established. This study lays a solid foundation for the design and development of potential HER catalysts in the future. • 2D WSn 2 N 4 Catalysts: Comprehensive analysis of WSn 2 N 4 materials for hydrogen evolution reaction (HER). • Transition Metal Doping: Effects of (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) doping at N and Sn sites in WSn 2 N 4 on catalysis. • Best Catalyst: Ti@W–WSn 2 N 4 shows optimal catalytic activity (ΔG H∗ = −0.004 eV). • Machine Learning Screening: Machine learning identified key features and enabled rapid catalyst evaluation. [ABSTRACT FROM AUTHOR]

The development of efficient catalysts for electrochemical water splitting has become a significant contemporary challenge. Transition metal oxides, due to their unique electrochemical properties, have emerged as promising candidates. Among these, a group of BiMeVO x -based compounds shows particular potential for practical applications in hydrogen and oxygen evolution reactions. However, improvement is still necessary to achieve stable operation of these catalysts in green hydrogen generation. With this is mind, in this study we synthesize BiMeVO x materials with graphene addition using a simple annealing in a tube furnace and investigate their electrochemical properties in HER and OER. After incorporating different metals into the BiMeVO x structure, we observed variations in electrochemical properties; materials with the addition of molybdenum and cobalt (BiMoVO x and BiCoVO x) outperformed materials containing zirconium and cerium (BiZrVO x and BiCeVO x). The BiMoVOx/C catalyst showed excellent HER performance with an overpotential of 432 mV at 10 mA/cm2 and a Tafel slope of 76 mV dec⁻1, while BiCoVOx/C exhibited superior OER activity with a Tafel slope of 100 mV dec⁻1, lower than that of commercial IrO₂. The addition of graphene improved the conductivity and overall activity of the catalysts. These findings indicate that metal doping and graphene incorporation are effective strategies for enhancing the performance of BiMeVOx-based materials in water splitting applications. [Display omitted] • The addition of molybdenum and cobalt to the BiMeVO x structure improve the electrochemical properties. • Graphene was found to contribute to increased sample conductivity and catalyst activity. • The addition of molybdenum and graphene in BiMoVOx/C increased activity in HER with an overpotential at 432 mV. • The addition of cobalt and graphene in BiCoVOx/C improved catalytic performance with the Tafel slope a 100 mV dec−1. [ABSTRACT FROM AUTHOR]

Hydrogen is an important candidate for the next generation of clean energy among the studied green energy. However, H 2 production efficiency is still low due to lack of efficient catalysts. Herein, the hydrogen evolution reaction (HER) performances of MSi 2 N 4 (M = Mo, W) and N (Si) defective structures with single transition metal (TM = Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, Mo, Ru, Pd, Ag, Ta, W, and Ir) and nonmetal (NM=B, O, P, and S) atoms doping are investigated by first principles calculations. The results show that N and Si vacancies promote HER activity of pristine MoSi 2 N 4 and WSi 2 N 4 , and N vacancy delivers relative higher HER activity than that of Si vacancy. Interestingly, the HER performance of MoSi 2 N 4 and WSi 2 N 4 can be further improved by tuning their electronic structure with NM and TM doping. O/MoSi 2 N 4 v and O/WSi 2 N 4 v deliver optimal Δ G H∗ values (Δ G H∗ = -0.09 eV and −0.21 eV, respectively) among the NM doped structures. Four of TM doped structures, Co/Mo Si 2 v N 4 , Co/W Si 2 v N 4 , Pd/Mo Si 2 v N 4 , and Pd/W Si 2 v N 4 deliver near-zero Δ G H∗ values, with the corresponding Δ G H∗ of −0.05, −0.01, 0.02, and 0.06 eV, respectively. More works suggest that there is a strong linear relationship between Δ G H∗ and descriptor ψ (related with valence-electron number and electronegativity), with the correlation coefficient R 2 are 0.91 and 0.76 for TM/Mo Si 2 v N 4 and TM/W Si 2 v N 4 , respectively, suggesting that ψ is a good descriptor for screening HER catalysts for TM doped M Si 2 v N 4 , especially for TM/Mo Si 2 v N 4 structures. In addition, the ψ -log (i 0) volcano curve indicates that when the ψ is about 9.15 eV (peak points), the TM doped structures obtained optimal HER activity. • N and Si vacancies promote the HER activity of pristine MSi 2 N 4 (M = Mo, and W). • Tuning electronic structure with NM and TM doping can adjust HER activity of MSi 2 N 4. • ψ is a good descriptor for screening HER catalysts for TM doped M Si 2 v N 4. [ABSTRACT FROM AUTHOR]

Exploring and fabricating noble-metal-free and cost-effective electrocatalysts to minimise the excessive potential required is of great significance for alkaline hydrogen evolution reaction (HER). Herein, we report FeS/1T-MP MoS 2 @rGO heterostructure with 1T and 2H mixed phase MoS 2 (1T-MP MoS 2) combining with FeS anchored on reduced graphene oxide (rGO) matrix, which is synthetized by utilizing Anderson polyoxometalate as Fe–Mo precursor by a facile hydrothermal method. The FeS/1T-MP MoS 2 @rGO heterostructure in the form of interconnected nanosheet arrays with multiple interfaces and rich-defects, which is in favor of the immersion of the electrolyte and exposing more active sites. Benefiting from the synergistic advantages of 1T-MoS 2 , FeS and rGO, FeS/1T-MP MoS 2 @rGO heterostructure delivers enhanced conductivity, enlarged electrochemical active surface area, and eventually promote the HER kinetics. As expected, FeS/1T-MP MoS 2 @rGO heterostructure emerges prominent HER activity with low overpotentials of 102 and 256 mV to achieve current density of 10 and 100 mA cm−2, outperforming vast majority of the advanced 1T MoS 2 -based alkaline HER electrocatalysts. The FeS/1T-MP MoS 2 @rGO heterostructure possesses multiple interfaces and massive defects interconnected nanosheet arrays that is fabricated by a 1T and 2H mixed phase MoS 2 (1T-MP MoS 2) combining with FeS anchored on reduced graphene oxide (rGO), emerging superior alkaline electrocatalytic hydrogen evolution reaction performances. [Display omitted] • 1T and 2H mixed phase MoS 2 combine with FeS anchored on rGO form FeS/1T-MP MoS 2 @rGO. • FeS/1T-MP MoS 2 @rGO heterostructure possesses multiple interfaces and rich defects. • The integration of 1T-MoS 2 , FeS and rGO enhance the conductivity and HER kinetics. • Phase engineering, heterostructure and defects deliver ideal alkaline HER activity. [ABSTRACT FROM AUTHOR]

An efficient and facile water dissociation process plays a crucial role in enhancing the activity of alkaline hydrogen evolution reaction (HER). Considering the intricate influence between interfacial water and intermediates in typical catalytic systems, meticulously engineered catalysts should be developed by modulating electron configurations and optimizing surface chemical bonds. Here, a high‐entropy double perovskite (HEDP) electrocatalyst La2(Co1/6Ni1/6Mg1/6Zn1/6Na1/6Li1/6)RuO6, achieving a reduced overpotential of 40.7 mV at 10 mA cm−2 and maintaining exemplary stability over 82 h in a 1 m KOH electrolyte is reported. Advanced spectral characterization and first‐principles calculations elucidate the electron transfer from Ru to Co and Ni positions, facilitated by alkali metal‐induced super‐exchange interaction in high‐entropy crystals. This significantly optimizes hydrogen adsorption energy and lowers the water decomposition barrier. Concurrently, the super‐exchange interaction enhances orbital hybridization and narrows the bandgap, thus improving catalytic efficiency and adsorption capacity while mitigating hysteresis‐driven proton transfer. The high‐entropy framework also ensures structural stability and longevity in alkaline environments. The work provides further insights into the formation mechanisms of HEDP and offers guidelines for discovering advanced, efficient hydrogen evolution catalysts through super‐exchange interaction. [ABSTRACT FROM AUTHOR]

Maintaining a consistently high current density growth rate in the hydrogen evolution reaction is highly challenging because the limited mass transfer rate at the electrode/electrolyte interface will make the adsorption reaction as the rate‐determining step associated with a low hydrogen coverage, exhibiting a Tafel slope >120 mV dec–1. Therefore, maximizing the current density range in which the desorption reaction is the rate‐determining step, can significantly reduce the overpotential. Herein, a surface sulfur decoration strategy is presented to modify the molybdenum carbide electrocatalyst and achieve coordinated adsorption/desorption kinetics, leading to a dominant Volmer–Heyrovsky mechanism across a wide range of current densities. Both experimental and theoretical results validate the surface charge redistribution induced by sulfur decoration, which subtly optimizes the Gibbs free energy of hydrogen adsorption and enhances the in‐plane polarization field. As a result, the as‐obtained surface sulfur‐decorated molybdenum carbide electrocatalyst exhibits coordinated adsorption/desorption kinetics and efficient hydrogen delivery, ultimately surpassing the commercial Pt/C electrocatalyst for high‐efficiency hydrogen evolution. [ABSTRACT FROM AUTHOR]

Methanol‐electrooxidation‐reaction (MOR) to value‐added formate is a promising alternative to water oxidation for cost‐efficient hydrogen production. It is generally proposed that the MOR kinetics on Ni‐based catalysts are highly limited by the transition rate of Ni(OH)2/NiOOH. Yet, how to define the catalyst following the direct pathway without Ni2+/Ni3+ transition remains challenging. Herein, a core@shell heterostructured NiMoPx@Ni5P4 catalyst is developed to selectively promote the MOR at a large current density (> 500 mA cm−2). A series of operando spectroscopic studies reveal negligible formation of NiOOH with 1.0 m methanol in a wide potential range, where MOR is predominant. Theoretical calculations demonstrate that the Ni‐P site of NiMoPx@Ni5P4 favors the adsorption of *CH3OH over *OH while the heterostructure contributes to the significantly reduced energy barrier of *OCH3 →*OCH2, hence promoting the MOR along a direct pathway without the formation of NiOOH. Moreover, further study suggests that the catalyst also performs well toward cathodic hydrogen evolution reaction (HER). As a result, an electrode pair of NiMoPx@Ni5P4//NiMoPx@Ni5P4 is employed to enable concurrent MOR/HER electrolysis at 1.81 V to yield formate/H2 with FEs of ca. 90/100% and long‐term (100‐h) sustainability at 500 mA cm−2 under the industrial conditions (6.0 m KOH, 65 °C). [ABSTRACT FROM AUTHOR]

Defects are inherent in transition metal dichalcogenides and significantly affect their chemical and physical properties. In this study, surface defect electrochemical nanopatterning is proposed as a promising method to tune in a controlled manner the electronic and functional properties of defective MoS₂ thin films. Using parallel electrochemical nanolithography, MoS₂ thin films are patterned, creating sulphur vacancy‐rich active zones alternated with defect‐free regions over a centimetre scale area, with sub‐micrometre spatial resolution. The patterned films display tailored optical and electronic properties due to the formation of sulphur vacancy‐rich areas. Moreover, the effectiveness of defect nanopatterning in tuning functional properties is demonstrated by studying the electrocatalytic activity for the hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

MXene, a family of 2D transition metal carbides and nitrides, presents promising applications in electrocatalysis. Maximizing its large surface area is key to developing efficient non‐noble‐metal catalysts for the hydrogen evolution reaction (HER). In this study, oxygen‐functionalized Ti3C2Tx MXene (Ti3C2Ox) is synthesized and deposited gold nanoparticles (Au NPs) onto it, forming a novel composite material, Au‐Ti3C2Ox. By selectively removing other functional groups, mainly ‐O functional groups are retained on the surface, directing electron transfer from Au NPs to MXene due to electronic metal‐support interaction (EMSI), thereby improving the catalytic activity of the MXene surface. Additionally, the interaction between Au NPs and ‐O functional groups further enhanced the overall catalytic activity, achieving an overpotential of 62 mV and a Tafel slope of 40.1 mV dec−1 at a current density of −10 mA cm−2 in 0.5 m H2SO4 solution. Density functional theory calculations and scanning electrochemical microscopy with ≤150 nm resolution confirmed the enhanced catalytic efficiency due to the specific interaction between Au NPs and Ti3C2Ox. This work provides a surface modification strategy to fully utilize the MXene surface and enhance the overall catalytic activity of MXene‐based catalysts. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A novel electrocatalyst, Ni‐Co/β‐Mo2C@C, was rationally designed to enhance the efficiency of the hydrogen evolution reaction (HER) in this work. Assembled with two‐dimensional Ni‐Co nanosheets onto Mo2C nanorods coated with a thin carbon shell, the catalyst demonstrates remarkable performance, including low overpotential (η10 = 57 mV) and reduced Tafel slope (63 mV·dec–1) in 0.5 mol·L–1 H2SO4 electrolyte. This innovative design strategy provides abundant active sites and efficient electron/ion transport pathways, effectively shortening reactant diffusion distances and enhancing electrocatalytic activity. Additionally, the carbon shell coating protects the catalyst from etching and agglomeration, ensuring its durability. This work presents a promising approach for engineering highly efficient metal carbide‐based HER catalysts through tailored composition and nanostructure design. [ABSTRACT FROM AUTHOR]

The complex compositional space of high entropy alloys (HEAs) has shown a great potential to reduce the cost and further increase the catalytic activity for hydrogen evolution reaction (HER) by compositional optimization. Without uncovering the specifics of the HER mechanism on a given HEA surface, it is unfeasible to apply compositional modifications to enhance the performance and save costs. In this work, a combination of density functional theory and Bayesian machine learning is used to demonstrate the unique catalytic mechanism of IrPdPtRhRu HEA catalysts for HER. At high coverage of underpotential‐deposited hydrogen, a d‐band investigation of the active sites of the HEA surface is conducted to elucidate the superior catalytic performance through electronic interactions between elements. At low coverage, a novel Bayesian learning with oversampling approach is then outlined to optimize the HEA composition for performance improvement and cost reduction. This approach proves more efficacious and efficient and yields higher‐quality structures with less training set bias compared with neural‐network optimization. The proposed HEA optimization theoretically outperforms benchmark Pt catalysts’ overpotential by ≈40% at a 15% reduced synthesis cost comparing to the equiatomic ratio HEA. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting for green hydrogen production necessitates effective electrocatalysts. Currently, commercial catalysts are primarily platinum-based. Therefore, finding catalysts with comparable catalytic activity but lower cost is essential. This paper describes spinel-structured catalysts containing nickel cobaltite NiCo2O4, graphene, and additionally doped with heteroatoms. The structure and elemental composition of the obtained materials were analyzed by research methods such as TEM, SEM-EDX, XRD, XPS, and Raman spectroscopy. The electrochemical measurements showed that hybrid materials containing nickel cobaltite NiCo2O4 doped with graphene are highly active catalysts in the hydrogen evolution reaction (Tafel slopes = 91 mV dec−1, overpotential = 468 mV and onset potential = -339 mV), while in the oxygen evolution reaction (Tafel slopes = 51 mV dec−1, overpotential = 1752 mV and onset potential = 370 mV), bare NiCo2O4 without the addition of carbon has a worse activity (for HER: Tafel slopes = 120 mV dec−1, overpotential - does not achieve and onset potential = -404 mV, for OER: Tafel slopes = 54 mV dec−1, overpotential = 1796 mV and onset potential = 410 mV). In terms of stability, comparable results were obtained for each synthesized compound for both the HER and OER reactions. [ABSTRACT FROM AUTHOR]

Rational construction of platinum (Pt)‐based single‐atom catalysts (SACs) with high utilization of active sites holds promise to achieve superior electrocatalytic alkaline HER performance, which requires the assistance of functional supports. In this work, a novel catalytic configuration is reported, namely, Pt SACs anchored on the nickel‐chromium oxides labeled as Pt SACs‐NiCrO3/NF. The mechanism associated with the metal‐support interaction (MSI) for synergy co‐catalysis that empowers efficient HER on Pt SACs‐NiCrO3/NF is clarified. Specifically, the modulated electron structure in Pt SACs‐NiCrO3 manipulates the interface microenvironment, mediating a more free water state, which is beneficial to accelerate front water dissociation behavior on the oxide support. Besides, the homogeneously distributed Pt sites with the created near‐acidic state ensure the subsequent fast proton‐involved reaction. All these determine the comprehensively accelerating HER kinetics. Consequently, Pt SACs‐NiCrO3/NF deliverers considerable HER performance, with overpotentials (η10/η100) of 23/122 mV, high mass activity of 382.77 mA mg−1Pt. When serving in an alkaline water‐based anion exchange membrane electrolytic cell (AEMWE), Pt SACs‐NiCrO3/NF also presents excellent performance (100 mA cm−2 at the cell voltage of 1.51 V and stable up to 100 h), confirming its good prospect. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) have recently attracted much attention in the scientific community as a prominent catalyst for oxygen evolution reaction (OER) because they are economical, extremely stable, and highly active. Literature on LDH alone and their hybrids for catalyzing water oxidation are readily available, but LDH catalyzing hydrogen evolution reaction (HER) is meager. Here, we synthesized Co/Al‐based LDH systems that efficiently perform as bifunctional electrocatalysts for both HER and OER. Exfoliation of this layered material via anion intercalation into a few layers further enhanced its activity. In this work, we reported the synthesis of Co/Al LDHs via coprecipitation followed by hydrothermal method and different surfactant‐functionalized LDHs (with anionic surfactant: SDS, cationic surfactant: CTAB, and nonionic surfactant: PEG 4000). SDS‐modified LDH (s LDH) showed notable stability and competent results in hydrogen evolution in addition to oxygen evolution. The exfoliation of s LDH caused enhancement in the high specific surface area about 6.8 times compared to pristine LDH, as evident from BET data. The onset potential for HER as obtained from the polarization curve for s LDH is −0.41 V versus RHE, with Tafel slope of 67.4 mV/dec. Similarly, OER onset potential and corresponding Tafel slope are 1.53 V versus RHE at 10 mA/cm2 and 90.2 mV/dec, respectively. [ABSTRACT FROM AUTHOR]

Electrolyzing seawater to produce hydrogen is a promising sustainable energy production technology. The current non-precious metal-based hydrogen evolution reaction (HER) electrocatalysts demonstrate inadequate catalytic activity and poor stability in seawater electrolyte. Therefore, developing stable and efficient non-precious metal-based HER electrocatalysts is a major challenge for achieving sustainable green energy development. This work reports a multi-component intermetallic catalyst FeCoCuAlMo prepared by arc melting and chemical dealloying methods. The electrocatalytic hydrogen evolution performance of catalysts with varying atomic ratios (FeCoCu) 20 (Al 70 Mo 30) 80 , (FeCoCu) 30 (Al 70 Mo 30) 70 , (FeCoCu) 40 (Al 70 Mo 30) 60 , and (FeCoCu) 50 (Al 70 Mo 30) 50 in alkaline seawater and alkaline electrolyte was studied. The findings indicate that these catalysts primarily consist of AlMo 3 and (Cu 0.35 Fe 0.35 Co 0.3)Al, among which the dealloyed (FeCoCu) 30 (Al 70 Mo 30) 70 exhibits excellent catalytic activity with overpotentials of 137.54 and 116.91 mV at a current density of 100 mA/cm2 in alkaline seawater and alkaline electrolyte, respectively, outperforming most catalysts. Additionally, it demonstrated long-term stability in alkaline seawater and alkaline electrolyte for 250 and 400 h without significant decay at overpotentials of 236 mV and 276 mV, respectively. This improved performance can be attributed to the unique structure of the multi-component intermetallic compound, which provides good thermodynamic stability and synergistic effects among its constituents, thereby enhancing HER performance. Within this multi-component intermetallic compound, AlMo 3 particles serve as the primary conductive medium to accelerate electron transfer, while (Cu 0.35 Fe 0.35 Co 0.3)Al serves as the main active site, resulting in a stable structure that provides the catalyst with high catalytic activity and good stability. Thus, the (FeCoCu) 30 (Al 70 Mo 30) 70 electrocatalyst is a promising candidate for seawater electrolysis aimed at hydrogen production. [Display omitted] • Intermetallic composed of AlMo 3 , Al 5 CuMo 2 , and (Cu 0.35 Fe 0.35 Co 0.3)Al was prepared. • AlMo 3 and (Cu 0.35 Fe 0.35 Co 0.3)Al provide pathways and active sites for the catalyst. • It exhibited an overpotentials of 137.54 mV at 100 mA/cm2 in alkaline seawater. • The catalyst shows excellent durability at overpotentials of 276 mV for 400 h. [ABSTRACT FROM AUTHOR]

In this study, for the first time, NiMnSe/CuP nanocomposite was successfully synthesized through a two-step electrochemical method and used as a novel electrocatalyst for hydrogen evolution reaction (HER). In the initial stage, a layer of CuP was deposited onto a nickel foam (NF) substrate. In the final stage, a layer of NiMnSe was deposited on top of the first layer by controlling the electrodeposition conditions. The optimization of both the duration time and potential was pursued to attain the highest level of catalytic activity. The optimized NiMnSe/CuP coating on NF demonstrates promising HER activity, at current densities of -10 and -100 mA. cm-2, with small overpotentials of -83 and -292 mV, respectively. The electrode's stability was tested under an industrial-scale current density of -100 mA. cm-2 for the HER, demonstrating good stability over at least 12 h. The findings revealed that the concurrent application of CuP and NiMnSe electrocatalysts yields a synergistic effect, increasing the surface-to-volume ratio and enhancing the number of active sites. The proposed electrode exhibits remarkable performance for the HER and offers a straightforward, rapid, and binder-free synthesis method, utilizing cost-effective materials for the electrocatalyst layer. As a result, it presents itself as a strong choice for applications in water splitting. • Binder-free and heterojunction-based electrocatalysts on nickel foam. • Optimized NiMnSe/CuP performs better for HER in alkaline media. • Stable, low-cost, and three-dimensional electrocatalysts for HER. • Electrode surface modification by TMPs with dynamic hydrogen bubble template method. • Superaerophobic/superhydrophilic properties of NiMnSe/CuP. [ABSTRACT FROM AUTHOR]

Although hydrogen represents a vital source of clean energy, the development of cost-effective, durable materials for use as catalysts in the hydrogen evolution reaction (HER) remains a challenge. In this work, covalent organic framework (COF) - derived core-shell microspheres were prepared as novel electrocatalysts. The previously prepared COF microspheres were pyrolyzed into nitrogen-doped porous carbon (N–C) as the core for enhanced electrocatalytic conductivity. With the assistance of a dual-ligand, the COF shell grew on the surface of N–C to form a core-shell microsphere, which was named N–C@COF. The surface morphology and core-shell structure of N–C@COF were characterized by SEM and TEM. FT-IR, TGA, and XPS were utilized to ascertain the synthesis of COF and the composition of the core-shell microspheres. The N–C@COF core-shell microspheres exhibited excellent HER performance in 1 M KOH electrolyte, demonstrating a low overpotential of 104 mV @ 10 mA cm−2, significantly outperforming pure COF and N–C. Furthermore, the N–C@COF demonstrated excellent HER stability over a 24 h period and retained its HER activity following 2000 consecutive cycles of electrolysis. The presence of the N–C core in the N–C@COF enhanced the electrical conductivity of the catalyst, while the COF shell provided abundant active sites for the HER, resulting in a synergistic improvement in the catalytic efficiency. This work presents a straightforward strategy for synthesizing COF-based multicomponent core-shell microspheres, which provides a promising pathway for the development of available and cost-effective electrocatalysts. [Display omitted] • COF-derived carbon microspheres as cores. • The N–C core significantly improves the electrical conductivity. • COF shells provide a large number of active sites for HER. • N–C@COF exhibited a low over-potential of 104 mV @ 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Aluminum air batteries have great potential as a state-of-the-art energy storage device due to their high capacity, energy density and fascinating safety. However, the disturbing hydrogen evolution reaction (HER) of the Al anode increase the gap between practical application and theoretical level. Electrolyte engineering with organic additives has been the spotlight to address the problem of HER. The polar functional group of organic molecules could bound with the water via the hydrogen bond to drop the activity of water. Unfortunately, the basic physicochemical properties of electrolyte would be deteriorated due to the organic matter, which has a negative impact on the electrochemical performance of batteries. Herein, an inorganic additive was adopted to regulate the hydrogen bond network and anode interface. The activity of H 2 O could be obviously suppressed by the stronger three-center-four-electron hydrogen bonds bridged by fluoride ions. And the water molecules are kept away from the anode surface due to the protective layer caused by the adsorption of fluoride ions. The HER could be greatly inhibited by both pathways, which reaches an inhibition efficiency of 55% in the electrolyte with 5 M KF. Correspondingly, the Al air battery exhibits a high discharge specific capacity of 1552.8 mAh g−1 and an energy density of 1829.51 Wh kg−1 at a current density of 25 mA cm−2. This work showcases a promising inorganic additive to suppress the HER for high-performance Al air battery. [Display omitted] • An inorganic additive was adopted to regulate hydrogen bond network. • The 3c4e hydrogen bond bridged by fluoride ion decreases the activity of H 2 O. • The fluoride ions constructure a protective layer for anode. • Al air battery exhibits high discharge capacity of 1552.8 mAh g−1 at 25 mA cm−2. [ABSTRACT FROM AUTHOR]

Hydrogen is a renewable and environmentally friendly energy carrier and is considered a viable alternative to fossil fuels. Consequently, developing electrodes with excellent hydrogen evolution electrocatalysis is a top priority in research. However, the use of flat electrodes as cathode substrates by most researchers limits the electrocatalytic active area of the prepared electrode. To address this issue, it is essential to prepare a micro-nano structure on a cathode substrate before electrodeposition. This study introduced a novel Ni nanocone/Grid electrode, obtained through a combined laser-electrodeposition process to investigate its electrocatalytic activity and stability for the hydrogen evolution reaction (HER). Various techniques, including linear sweep voltammetry (LSV), electrochemical impedance spectra (EIS), cyclic voltammetry (CV), and chronopotentiometry (CP) in 1 M KOH solution, were employed to assess the HER electrocatalytic performance of the Ni nanocone/Grid electrodes. The experimental results demonstrated that the electrodes could achieve current densities of -10, -20, and -100 mA/cm2 with corresponding overpotentials of -281, -308, and -390 mV, respectively. Additionally, the Tafel slope of these electrodes was found to be only -82.05 mV/dec. The enhanced catalytic performance of the electrode was attributed to the synergistic effect of the grid-like and nanocone structures, which significantly increased the electrocatalytically active area and improved surface hydrophilicity, thereby boosting electrocatalytic performance. The simplicity of the preparation method and the exceptional performance of the electrode provide a promising new avenue for future research on HER electrocatalysts. • A new laser-electrodeposition combined process was proposed to prepare the catalytic electrode for hydrogen evolution. • Ni nanocone/Grid showed low overpotential and Tafel slope for hydrogen evolution. • The combination of grid structure and nanocone can significantly increase the ECSA of the electrode. • The electrode shows excellent hydrophilicity and extraordinary durability. [ABSTRACT FROM AUTHOR]

The development of an efficient yet cost-effective non-precious electrocatalyst for the hydrogen evolution reaction (HER) in alkaline water and seawater systems remains a formidable obstacle to the large-scale production of hydrogen energy, stemming from the sluggish kinetics of electron transfer reactions during the HER process. In this article, an amorphous Co-P-W electrocatalyst on nickel foam is prepared using a brief cyclic voltammetry (CV) electrodeposition method. The optimized Co-P-W electrocatalyst exhibits excellent electrocatalytic performance for HER, which only requires overpotentials of 59 and 143 mV to achieve a current density of 10 mA cm−2 in alkaline water (1.0 M KOH) and alkaline seawater (1.0 M KOH + natural seawater), respectively, and remarkable stability and durability. The improved HER performance of the Co-P-W electrocatalyst is attributed to the introduction of W, which modulates the electronic structure of Co and P, optimizes the adsorption/dissociation of H 2 O, and reduces the charge transfer resistance of the Co-P electrocatalyst, thus improving the kinetics of the HER. Furthermore, the W-doping significantly enhances the hydrophilicity of the Co-P electrocatalyst, which favors rapid and thorough penetration of electrolytes into the electrocatalyst, facilitating the formation of a highly accessible reaction interface, ultimately resulting in excellent HER activity. Our findings demonstrate the feasibility of designing an efficient, durable, and scalable electrocatalyst to significantly boost HER efficiency for practical water electrolysis. [Display omitted] • Binder-free Co-P-W catalyst for electrocatalytic hydrogen production was developed via electrodeposition method. • The low η 10 in alkaline water and seawater were 59 and 143 mV, respectively. • Mo adjusts the electronic structure to optimize the adsorption/dissociation of H 2 O. • W doping increases the active area, enhances the conductivity and hydrophilicity, and greatly improves its intrinsic activity. [ABSTRACT FROM AUTHOR]

With the ever‐growing global demand for sustainable energy solutions, hydrogen has garnered significant attention as a clean, efficient, and renewable energy source. In the field of hydrogen production, catalyst research stands out as one of the foremost areas of focus. In recent years, the preparation of electrocatalysts using ionic liquids (ILs) and deep eutectic solvents (DESs) has attracted widespread attention. ILs and DESs possess unique physicochemical properties and are recognized as green media as well as functional materials. Cobalt‐based catalysts have proven to be efficient electrocatalysts for water splitting. Incorporating ILs or DESs into the preparation of cobalt‐based catalysts offers a remarkable advantage by allowing precise control over their structural design and composition. This control directly influences the adsorption properties of the catalyst's surface and the stability of reaction intermediates, thereby enabling enhanced control over reaction pathways and product selectivity. Consequently, the catalytic activity and stability of cobalt‐based catalysts can be effectively improved. In the process of preparing cobalt‐based catalysts, ILs and DESs can serve as solvents and templates. Owing to the good solubility of ILs and DESs, they can efficiently dissolve raw materials and provide a special nucleation and growth environment, obtaining catalysts with novel‐structures. The main focus of this review is to provide a detailed introduction to metal cobalt and its oxide/hydroxide derivatives in the field of water splitting, with a particular emphasis on the research progress achieved through the utilization of IL and DES. The aim is to assist readers in designing and synthesizing novel and high‐performance electrochemical catalysts. [ABSTRACT FROM AUTHOR]

The design of multifunctional materials for energy storage and conversion systems is vital in addressing present global energy issues. In this work, we have prepared a highly active and economical hybrid material comprising ZnO and Nb2O5, integrated with g-C3N4 (Nb@ZGCN) through the simple chemical method followed by calcination process. The resultant Nb@ZGCN electrode delivered a specific capacitance of 122.3 F g−1 at a current density of 1 A g−1 and maintained 71% of its initial value at a current density of 4 A g−1 in a 6 M KOH electrolyte. This hybrid electrode exhibited superb cyclic stability of 105% even after 2000 cycles at 4 A g−1 with an increased coulomb efficiency than the first cycle which is close to 100%. Additionally, the prepared hybrid material was further applied for electrocatalytic hydrogen evolution reaction (HER), delivering a small overpotential of 252.1 mV to achieve a current rate of 10 mA cm− 2 along with long-term durability in a 1 M KOH medium. The synergistic interaction between the ZnO, Nb2O5 and graphitic carbon nitride in the hybrid structure leads to abundant electroactive sites that remarkably improve the supercapacitive and HER activities. These results suggest that the developed hybrid material can be further exploited as an electrode material for supercapacitor and water splitting applications. [ABSTRACT FROM AUTHOR]

Two-dimensional transition metal borides (MBenes) have emerged as promising electrocatalysts for hydrogen evolution reactions (HERs), attracting significant research interest due to theoretical computations that enhance the understanding and optimization of their performance. This review begins with a comprehensive summary of HER mechanisms, followed by an in-depth examination of the geometric and electronic properties of MBenes. Subsequently, this review explores MBene-based electrocatalysts for HERs, employing free-energy diagrams and an electronic structure analysis to assess both the intrinsic catalytic activity of MBenes and the theoretical performance of single-atom modified MBenes. Finally, the prospects and challenges associated with MBenes are discussed, providing valuable insights to guide future research in this area. Overall, this topic holds significant relevance for researchers in the HER field, and this review aims to deliver theoretical insights for the optimal design of advanced MBene electrocatalysts. [ABSTRACT FROM AUTHOR]