Hydrogen Evolution Reaction Research Articles

Visualization of the Key Proton Activities in Hydrogen Evolution Reaction by Electrochromic Catalyst.

The electrocatalytic hydrogen evolution reaction (HER) is a promising route to produce sustainable hydrogen energy carrier for global carbon neutrality. The HER performance is largely determined by the overall proton activities, but the identification of such key proton activities in microscopic HER process is rather difficult. Herein, the study demonstrates a visualized HER concept by integrating the fundamental HER process with electrochromic technology on a well-designed Pt@WO3 platform in acidic electrolyte, where the overall proton activities in HER process can be rapidly discriminated by the color changes of Pt@WO3 electrochromic electrode. In contrast to bare WO3 counterpart, the Pt@WO3 electrochromic electrode displays a rather more positive potential of initial-coloration state and faster decoloration rate associated with significantly improved reaction kinetics of hydrogen intercalation and deintercalation within WO3 component. Correspondingly, the as-prepared Pt@WO3 catalyst electrode exhibits a remarkable HER activity with a lower onset-potential (45mV, proton adsorption and accumulation) and smaller Tafel slope (50mVdec-1, proton desorption), nearly 11.1- and 3.5-fold enhancement than those of bare WO3 counterpart. It is believed that the work in integrating the interesting visualization functionality into fundamental HER process may improve the readability of such microscopic electrocatalytic reaction and advance the exploration of more intelligent electrocatalysts.

Bimetallic Tandem Strategy for Effective Modulation of CO2 Electrocatalytic Selectivity on Relatively Inert Cu Interfaces.

The development of effective strategies to enhance the activity and selectivity of Cu-based catalysts for the CO2 reduction reaction (CO2RR) remains a critical challenge, particularly on relatively inert Cu facets that are highly active in the competitive hydrogen evolution reaction (HER). In this study, a series of Cu-M (M = Au, Ag, Pd) bimetallic tandem interfaces are fabricated on Cu nanocolumn arrays (Cu NCAs) with predominantly exposed Cu (200) facets. These interfaces excited a significant number of Cu+ species and modulated the adsorption behavior of critical intermediates for CO2RR, resulting in improved CO2RR activity and a substantial reduction in the competitive HER. Notably, the Cu-Au, Cu-Ag, and Cu-Pd NCAs displayed excellent selectivity for C2H4, CO, and HCOOH products, with optimized faradaic efficiency (FE) of ≈43.2, ≈48.0, and ≈50.7%, respectively. According to in situ spectroscopic analysis, each Cu-M interface exhibited distinct catalytic pathways: Cu-Au favored *COOH and *CO adsorption followed by C-C coupling for C2H4 production, Cu-Ag promoted *CO desorption for CO generation, and Cu-Pd facilitated *OCHO formation for HCOOH production. This study provides a strategy to design high-performance and more practical bimetallic Cu-based catalytic electrodes by directly modifying various commercial Cu substrates.

First-Principles Study on the CO2 Reduction Reaction (CO2RR) Performance of h-BN-Based Single-Atom Catalysts Modified with Transition Metals

The reasonable design of low-cost, high-activity single-atom catalysts (SACs) is crucial for achieving highly efficient electrochemical CO2RR. In this study, we systematically explore, using density functional theory (DFT), the performance of transition metal (TM = Mn, Fe, Co, Ni, Cu, Zn)-doped defect-type hexagonal boron nitride (h-BN) SACs TM@B−1N (B vacancy) and TM@BN−1 (N vacancy) in both CO2RR and the hydrogen evolution reaction (HER). Integrated crystal orbital Hamiltonian population (ICOHP) analysis reveals that these catalysts weaken the sp orbital hybridization of CO2, which promotes the formation of radical-state intermediates and significantly reduces the energy barrier for the hydrogenation reaction. Therefore, these theoretical calculations indicate that the Mn, Fe, Co@B−1N, and Co@BN−1 systems demonstrate excellent CO2 chemical adsorption properties. In the CO2RR pathway, Mn@B−1N exhibits the lowest limiting potential (UL = −0.524 V), and its higher d-band center (−0.334 eV), which aligns optimally with the adsorbate orbitals, highlights its excellent catalytic activity. Notably, Co@BN−1 exhibits the highest activity in HER, while UL is −0.217 V. Furthermore, comparative analysis reveals that Mn@B−1N shows 16.4 times higher selectivity for CO2RR than for HER. This study provides a theoretical framework for designing bifunctional SACs with selective reaction pathways. Mn@B−1N shows considerable potential for selective CO2 conversion, while Co@BN−1 demonstrates promising prospects for efficient hydrogen production.

A novel electrodeposited nanocatalyst of nickel nanoparticles and reduced graphene oxide doped with halogens for hydrogen evolution reaction

Developing non-noble and high-performance metal hydrogen evolution reaction (HER) electrocatalysts is significant for hydrogen production. Doping heteroatoms on the surface of graphene is another amazing measure to improve the catalytic behavior of catalysts. In this work, halogen-doped reduced graphene oxide with nickel nanoparticles (Ni-XRGO) was investigated as an innovative electrocatalyst for the HER. The scanning electron microscopy images of the Ni-XRGO catalyst showed the leaf-like structure morphology with wide distribution. Also, the energy-dispersive X-ray spectroscopy, mapping technique, confirmed that the presence of halogens caused the homogenous distribution of Ni nanoparticles. X-ray diffraction technique confirmed the presence of doped halogens in reduced graphene oxide. The Ni-XRGO electrode with only 61 mV vs. RHE onset potential, 41 mV dec−1 Tafel slope, good lifetime stability, and low charge transfer resistance could be a promising cathodic electrode for catalysis of HER. The particular electrochemical performance is due to the influence of the halogen elements on the charge distribution of the graphene surface; this leads to an enhancement in the exposure of additional active sites and an extension of the electrochemical active area. Our study presents a novel approach to the development of non-precious metal electrocatalysts that are both highly efficient and cost-effective for HER.

Multivariate covalent organic frameworks with tailored electrostatic potential promote nitrate electroreduction to ammonia in acid

The direct synthesis of ammonia from nitrate (NO3–) reduction in acid is a promising approach for industrialization. However, the difficulty arises from the intense competition with the inevitable hydrogen evolution reaction, which is favoured due to the overwhelming protons (H+). Here, we systematically explore and rationally optimize the microenvironment using multivariate covalent organic frameworks (COFs) as catalyst adlayers to promote the nitrate-to-ammonia conversion in acid. With the application of tailored positive electrostatic potential generated over the multivariate COFs, both the mass transfer of NO3– and H+ are regulated via appropriate electrostatic interactions, thus realizing the priority of NO3RR with respect to HER or NO3–-to-NO2–. As a result, an NH3 yield rate of 11.01 mmol h–1 mg–1 and a corresponding Faradaic efficiency of 91.0% are attained, and solid NH4Cl with a high purity of 96.2% is directly collected in acid; therefore, this method provides a practical approach for economically valorising wastewater into valuable ammonia.

Unlocking the Potential of Moiré Superlattices in Electrocatalysis, Photocatalysis, and Piezo-Photocatalysis.

Moiré superlattices, a distinct class of 2D material structures, have showcased immense potential for catalytic applications in recent years. Their unique electronic structures and geometric configurations offer numerous active sites and optimized reaction pathways, thereby significantly enhancing catalytic performance. This review presents an overview of the latest progress in the application of moiré superlattice materials in electrocatalysis, photocatalysis, and piezo-photocatalysis. It is first introduced recent advances in the study of 2D materials with moiré superlattice structures in electrocatalysis, with a particular emphasis on the application of moiré metals in the hydrogen evolution reaction. Notably, recent breakthroughs demonstrate that moiré-patterned catalysts exhibit superior catalytic activity, surpassing commercial Pt/C catalysts in critical performance indicators. Subsequently, the distinct benefits of moiré superlattices in photocatalytic methane reforming are underscored. Moiré superlattice catalysts enable efficient methane conversion under significantly reduced energy consumption while maintaining a remarkable selectivity of up to 96%. Last but not least, this review highlights the exceptional performance of moiré superlattice structures in nitrate synthesis. The synergistic effects in this superlattice achieve an exceptional nitrate production rate of 15.44mgg-1h-1 under ultrasound and light irradiation. By exploring the catalytic mechanisms behind these avant-garde applications, this review aspires to deepen the understanding of moiré superlattices in catalytic science and technology, thereby facilitating further research and novel applications.

Quantifying Localized Surface Plasmon Resonance Induced Enhancement on Metal@Cu2O Composites for Photoelectrochemical Water Splitting.

The localized surface plasmon resonance (LSPR) of metal nanoparticles can substantially enhance the activity of photoelectrocatalytic (PEC) reactions. However, quantifying the respective contributions of different LSPR mechanisms to the enhancement of PEC performance remains an urgent challenge. In this work, Cu@Cu2O composites prepared by annealing Cu2O under an inert atmosphere and electrodeposited metal@Cu2O composites (MED@Cu2O, MED = CuED, AuED, AgED, PdED, PtED) are employed as platform materials to investigate the LSPR effect on the PEC hydrogen evolution reaction (HER). All the composites exhibited remarkably LSPR-enhanced activity toward PEC HER. The contributions of two LSPR mechanisms, plasmon induced resonance energy transfer (PIRET) and hot electron transfer (HET), to the photocurrent on Cu@Cu2O and CuED@Cu2O are quantified by using different bands of incident light. Moreover, using MED@Cu2O composites, the effects of both the metal species and the applied potential on HET are quantitatively investigated. The results reveal that a pronounced HET enhancement occurs only when the LSPR peak energy is lower than the semiconductor bandgap energy (Eg) and that HET strengthens as the applied potential becomes more negative for PEC HER. This work therefore provides a quantitative understanding of the roles of PIRET and HET in boosting PEC activity.

Mechanistic Insights to Cation Effects in Electrolytes for Electrocatalysis.

Traditional understanding of electrocatalytic reactions has primarily focused on the covalent interactions between adsorbates and catalyst surfaces, often overlooking the significant influence of the electrolyte on the catalytic process. Recently, researchers have highlighted the pivotal role of cations in the electrolyte, demonstrating their capability to modulate the reaction pathways and thus the activity and selectivity. These findings underscore the need for a deeper, atomic-level understanding of the electrode-electrolyte interface. This perspective presents the mechanisms through which cations affect electrocatalysis, with a focus on the hydrogen-bond network, the adsorption behavior of reaction intermediates, the electric field within the electrochemical double layer, and the local electronic properties of catalysts. It provides a summary of the influences of cations on various electrocatalytic reactions, including hydrogen oxidation reaction (HOR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), nitrogen reduction reaction (NRR), nitrate reduction reaction (NO3-RR), and carbon dioxide reduction reaction (CO2RR). At the end, future research directions are provided to maximize the potential of leveraging the cation effects in the design of more efficient electrolyte systems.

Defect-Engineered Multi-Intermetallic Heterostructures as Multisite Electrocatalysts for Efficient Water Splitting.

Efficient water splitting for renewable hydrogen production requires the development of highly active and stable electrocatalysts. This study investigates the design and synthesis of defect-engineered multimetallic heterostructures as advanced electrocatalysts for overall water splitting. A synergistic approach combining atomic-scale defect engineering and multiphase heterostructures is employed to enhance catalytic activity. A series of highly porous intermetallic alloys (CoCuMoNi) with abundant defect sites are synthesized using a high-temperature alloying-dealloying technique. Due to the synergistic effect of multiphase interfaces, built-in electric fields, and defect engineering, the CoCuMoNi catalyst exhibits excellent bifunctional activity for water splitting (Hydrogen evolution reaction: 14mV@10 mA cm-2; Oxygen evolution reaction (OER): 211mV@10mAcm-2; Overall water splitting: 1.559V@100mAcm-2), with significantly enhanced activity compared to pure metals and conventional materials. Additionally, these structures demonstrate excellent stability and durability. Advanced characterization techniques and density functional theory (DFT) reveal that the formation of defect sites and heterojunctions not only induces electronic modulation but also enhances intermetallic interactions and charge transfer from Ni and Mo to Cu and Co, facilitating intermediate formation and transformation, thereby boosting intrinsic activity. This work highlights the potential of defect-engineered multimetallic heterostructures as scalable and efficient electrocatalytic platforms, paving the way for their practical applications in clean energy technologies.

Doping C60 with single or dual fe atoms for nitrogen reduction reaction: a DFT study

Abstract In this work, we conducted a detailed investigation of the catalytic mechanism of the electrocatalytic nitrogen reduction reaction (NRR) by density functional theory (DFT) calculations, focusing on fullerene (C60) doped with single or dual Fe atoms. The results indicate that single or dual Fe atoms can be stably embedded within defective C60, yielding Fe1C59 and Fe2C58, respectively. Both catalysts exhibit excellent performance in the adsorption and activation of N2, with Fe2C58 demonstrating a certain degree of superiority. Based on the investigation of the NRR reaction pathways on these catalysts, it has been found that, despite varying pathways in different systems, the rate-determining step (RDS) is consistently the first hydrogenation step *N2 → *NNH. Both thermodynamic and kinetic analyses indicate that Fe2C58 exhibits superior catalytic performance compared to Fe1C59. Specifically, the energy barrier for the RDS of the optimal reaction pathway on Fe2C58 is only 0.690 eV. Additionally, Fe2C58 also demonstrates an advantage in suppressing the competitive hydrogen evolution reaction (HER). The present work demonstrates that a catalyst composed of C60 doped with dual Fe atoms exhibits superior stability, electrocatalytic activity, and selectivity for NRR compared to a catalyst doped with a single Fe atom. This research provides a foundation for the design and synthesis of other heteroatom-doped fullerene catalysts.

Single-Atom Sb-Doped RuSbOx Bifunctional Catalysts for Ultra-Stable PEM Water Electrolyzers.

Developing highly efficient and stable Pt/Ir-free bifunctional catalysts is very urgent for lowering the catalyst cost of proton exchange membrane water electrolyzer (PEMWE). Herein, a single-atom Sb-doped RuSbOx bifunctional catalyst is developed for ultra-stable PEMWE. RuSbOx exhibits excellent stability with a long-term operation of 150h for oxygen evolution reaction (OER) and 300h for hydrogen evolution reaction (HER) at 100mA cm-2 in acidic media, respectively. Impressively, the PEMWE with RuSbOx as bifunctional catalysts only needs 1.72 to reach 1.0 A cm-2, and can maintain stable operation for 200h at 200mA cm-2. The in situ Raman and molecular probe methods reveal that the single-atom Sb doping can reconstruct the interfacial water structure on the surface of RuSbOx, resulting in an enriched supply of free water, accelerating the deprotonation process and reducing the local acidity of the catalyst surface, thereby improving the acidic OER activity and stability. Density functional theory calculations further confirm the above experimental results. In short, this work reveals that Sb is an outstanding structural stabilizer, and single-atom Sb-doping can maximize the OER stability of Ru-based catalysts in acid, which provides a useful strategy for designing ultra-stable electrocatalysts for PEMWE.

Electrosynthesis of pure urea from pretreated flue gas in a proton-limited environment established in a porous solid-state electrolyte electrolyser.

The electrosynthesis of pure urea via the co-reduction of CO2 and N2 remains challenging. Here we show that a proton-limited environment established in an electrolyser equipped with porous solid-state electrolyte, devoid of an aqueous electrolyte, can suppress the hydrogen evolution reaction and excessive hydrogenation of N2 to ammonia. This can instead be conducive to the C-N coupling of *CO2 with *NHNH (the intermediate from the semi-hydrogenation of N2), thereby facilitating the production of urea. By using nanosheets of an ultrathin two-dimensional metal-azolate framework with cyclic heterotrimetal clusters as catalyst, the Faradaic efficiency of urea production from pretreated flue gas (which contains mainly 85% N2 and 15% CO2) is as high as 65.5%, and no ammonia and other liquid products were generated. At a low cell voltage of 2.0 V, the current can reach 100 mA, and the urea production rate is as high as 5.07 g gcat-1 h-1 or 84.4 mmol gcat-1 h-1. Notably, it can continuously produce 6.2 wt% pure urea aqueous solution for at least 30 h, and about 1.24 g pure urea solid was obtained. The use of pretreated flue gas as a direct feedstock significantly reduces input costs, and the high reaction rate and selectivity contribute to a reduction in system scale and operational costs.

Atomic-Level Engineering of Transition Metal Dichalcogenides for Enhanced Hydrogen Evolution Reaction.

2D transition metal dichalcogenides (2D-TMDs) have attracted considerable attention due to their characteristic layered structures, which provide abundant accessible surface sites. Significant research efforts are dedicated to designing nanostructures and regulating electron properties to enhance the catalytic performance of the hydrogen evolution reaction (HER) of TMDs. However, elucidating the HER mechanism, particularly the role of active sites, remains challenging owing to the complex surface and electronic structures introduced by nanoscale modification. Recent advances have focused on achieving efficient HER catalysis through atomic-level control of TMD surface structures and precise identification of the coordination environment of active sites. Atomic-level engineering of TMDs, including incorporating or removing specific atoms onto the basal surfaces or within the interlayer via advanced synthetic approaches, has emerged as a promising strategy. These modifications optimize the adsorption/desorption energy of H, increase the density of active sites, and create synergetic active sites by arranging atoms in controlled configuration, in single-atomic modified TMDs (SA-TMDs) catalysts. Further, the insights of a notable increase of HER performance in SA-TMDs are discussed in detail when compared to both their pure and conventionally doped counterparts. This review aims to advance the understanding of atomic-level catalysis and provides a basis for developing next-generation materials for energy applications.

Recent Strategies for Ni3S2-Based Electrocatalysts with Enhanced Hydrogen Evolution Performance: A Tutorial Review

Water electrolysis represents one of the most environmentally friendly methods for hydrogen production, while its overall efficiency is primarily governed by the electrocatalyst. Nickel sulfides, e.g., Ni3S2, are considered to be highly promising catalysts for the hydrogen evolution reaction (HER) due to their distinctive chemical structure. However, the practical application of Ni3S2-based electrocatalysts is hindered by unsatisfactory high overpotential in the HER and weakened catalytic performance under alkaline conditions. Therefore, in this regard, further research on Ni3S2-based catalysts is being carried out to tackle these challenges. This review provides a comprehensive survey of the latest advancements in Ni3S2-based in improving the HER performance of Ni3S2-based electrocatalysts. The review may offer some inspiration for the rational design and synthesis of novel transition metal-based catalysts with enhanced water electrolysis performance.

Co- and Sn-Doped YMnO3 Perovskites for Electrocatalytic Water-Splitting and Photocatalytic Pollutant Degradation

The current environmental pollution and energy crises are global concerns that must be addressed. Considering this background, three perovskites (YMnO3, Co-doped YMnO3, and Sn-doped YMnO3) were synthesized via a sol–gel method and characterized by XRD, SEM, and EDX. Their water-splitting electrocatalytic activity was evaluated in a strongly alkaline medium. The highest activity was observed during hydrogen evolution reaction (HER) experiments on a glassy carbon electrode coated with a catalyst ink containing the Co-doped material. Initially, the HER overpotential value at −10 mA/cm2 was 0.59 V, and the Tafel slope was 115 mV/dec. Following a chronoamperometric stability test, the overpotential became 0.46 V and the Tafel slope 119 mV/dec. The higher HER activity of the modified electrode is ascribed to a higher number of catalytic sites exposed to the electrolyte solution and the presence of Carbon Black. The photocatalytic activity of the perovskites was investigated as well, using different experimental conditions and simulated solar irradiation. The results show that the photocatalytic activity can be improved by doping, and the highest removal efficiency is achieved in the presence of the Co-doped YMnO3 when ~60% of 17α-ethynylestradiol is degraded. Furthermore, the initial pH has no favorable effect on the degradation efficiency. The reusability of Co-doped YMnO3 was also tested and minimal activity loss was found after three photocatalytic cycles.

Cu‐Sn Alloy Nanoparticles Modified Carbon Nanofibers for Dendrite‐Free Zinc Ion Batteries

Aqueous zinc ion batteries (ZIBs) are currently highly promising rechargeable batteries offering affordable prices and high reliability. However, the uncontrolled expansion of zinc dendrites, hydrogen evolution reaction, and adverse reaction greatly affect their potential sustainable application. In this work, we constructed Cu‐Sn nanoparticle alloy modified carbon nanofibers (Cu/Sn‐C) as a buffer interface region (BIR) onto the zinc anode. The high density of zincophilic sites of the Cu/Sn‐C contributed a homogeneous Zn deposition behavior, ameliorated potential separator penetration of zinc dendrites, and weakened corrosions and adverse reactions. As a result, Cu/Sn‐C exhibits a low zinc nucleation overpotential of 33.2 mV and dendrite‐free zinc deposition. Besides, a symmetric cell with Cu/Sn‐C@Zn anode exhibits outstanding cycling lifespan with over 3500 hours at 1 mA cm‐2 for 1 mAh cm‐2. Furthermore, Cu/Sn‐C@Zn//MnxV2O5 full battery also achieved stable cycling at 5 A g‐1. This work provides a significant avenue for enhancing the reliability of the Zn anode, thereby facilitating the advancement of widespread applications for the next‐generation AZIBs.

Effect of Ligand Backbone on the Electrochemical Hydrogen Evolution Reaction and Hydrogen-Atom-Transfer Reactivity Using a Nickel Polypyridine Quinoline Complex.

Redox-active quinoline-containing [NiII(2PyN2Q) (H2O)]2+ complex (1) has been developed for the electrocatalytic (e) hydrogen evolution reaction (HER) in the presence of organic acids and water and for the hydrogen-atom-transfer (HAT) reaction with styrene in the presence of acids. Complex 1 shows promising e-HER performance in water up to pH 9. It exhibits a stepwise (E)ECEC mechanism with AcOH, while a potential-dependent bimolecular homolytic pathway and CEEC mechanism is operative with p-toluene sulfonic acid during the e-HER. The one- and two-electron-reduced species of 1 are characterized by spectro-electrochemistry, optical, and EPR studies. Moreover, the inverse kinetic isotope effect (KIE = 0.83) between AcOH and d4-AcOH during the e-HER and e-HAT with styrene for the hydro-functionalization reaction using catalyst 1 possibly suggests the involvement of nickel hydride species. The e-HER and e-HAT reactivity of 1 have been compared with redox-inactive redox-inactive [NiII(N4Py)(H2O)]2+ (2), demonstrating the prominent effect of quinoline in the e-HER and pyridine in the e-HAT. The proposed mechanism of the e-HER with AcOH is well supported by DFT studies.

Ultrafast Synthesis of Single-Atom Catalysts for Electrocatalytic Applications.

A recent development in catalytic research, single-atom catalysts (SACs) are one of the most significant categories of catalytic materials. During preparation, individual atoms migrate and agglomerate due to the high surface free energy. The rapid thermal shock strategy addresses this challenge by employing instantaneous high-temperature pulses to synthesize SACs, while minimizing heating duration to prevent metal aggregation and substrate degradation, thereby preserving atomic-level dispersion. The resultant SACs exhibit exceptional catalytic activity, remarkable selectivity, and long-term stability, which have attracted extensive attention in electrocatalysis. In this paper, cutting-edge ultrafast synthesis techniques such as Joule heating, microwave radiation, pulsed discharge, and arc discharge are comprehensively analyzed. Their ability is emphasized to achieve uniform dispersion of separated metal atoms and optimize the catalytic activity for electrocatalytic applications. A systematic summary of SACs synthesized by these rapid methods is provided, with particular emphasis on their implementation in carbon dioxide reduction reaction (CO2RR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR) systems. The review provides an in-depth discussion on the rapid synthesis strategy for development trend, remaining challenges, and the application prospects in electrocatalysis.

Probing nuclear quantum effects in electrocatalysis via a machine-learning enhanced grand canonical constant potential approach

Proton-coupled electron transfer (PCET) is the key step for energy conversion in electrocatalysis. Atomic-scale simulation acts as an indispensable tool to provide a microscopic understanding of PCET. However, consideration of the quantum nature of transferring protons under an exact grand canonical constant potential condition is a great challenge for theoretical electrocatalysis. Here, we develop a unified computational framework to explicitly treat nuclear quantum effects (NQEs) by a sufficient grand canonical sampling, further assisted by a machine learning force field adapted for electrochemical conditions. Our work demonstrates a non-negligible impact of NQEs on PCET simulations for hydrogen evolution reaction at room temperature, and provides a physical picture that wave-like quantum characteristic of the transferring protons facilitates the particles to tunnel through classical barriers in PCET paths, leading to a remarkable activation energy reduction compared to classical simulations. Moreover, the physical insight of NQEs may reshape our fundamental understanding of other types of PCET reactions in broader scenarios of energy conversion processes.

Enhancing Built‐in Electric Field via Balancing Interfacial Atom Orbit Hybridization at Boride@Sulfide Heterostructure for Hydrogen Evolution Reaction

Exploring nonprecious metal‐based catalysts for cathodic hydrogen evolution reaction (HER) has facilitated the realization of hydrogen economy toward water electrolysis in alkaline media. However, the difficult water dissociation process for the Volmer step (H2O → H* + OH*) and the subsequent unsuitable OH* adsorption energy on nonprecious metal‐based catalysts severely reduced the kinetics of HER. Herein, the universal synthesis for a series of transition metal (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W)‐based boride@sulfide heterostructured catalysts was realized by using molten‐salt method to conduct the in situ boronization of commercial sulfides. Significantly, WB2@WS2 heterostructured catalyst exhibits excellent catalytic activity and stability for HER. Balancing interfacial atom orbit hybridization between W(d)‐B(s,p) and W(d)‐S(s,p) at WB2@WS2 heterostructured interface enhances the built‐in electric field. In situ Raman spectroscopy and density functional theory calculation results reveal that the built‐in electric field in WB2@WS2 optimizes the adsorption and desorption of OH* intermediate, favoring the enhancement of catalytic performance toward HER. Besides, the rate‐determining step over WS2, which is generally considered to be the Volmer step, was changed to the step of OH* desorption over WB2@WS2, and thus the corresponding energy barrier was decreased.