摘要：The development of inexpensive and efficient Pt-free electrocatalysts for the hydrogen evolution reaction(HER)is greatly crucial for water *** carbide(WC)exhibiting a Pt-like electronic structure represents an attractive alternative,although its overall performance is limited by the strong W-H bond that impedes hydrogen ***,we employed an in-situ interface engineering strategy to construct high-performance and cost effective electrocatalysts comprising WC/tungsten phosphide(WP)heterostructures that were anchored on N,P-codoped carbon(WC/WP@NPC)via a one-step pyrolysis of a melamine polyphosphate/WO_(3) hybrid in an inert *** to the crystal structure compatibility and electron-rich property of WP,it optimizes the electronic structure and hydrogen adsorption configuration of WC,thus significantly weakening the W-H bond with a thermoneutral Gibbs free energy of hydrogen adsorption(ΔG_(H^(*)))of−0.05 ***,NPC ensures fast electron transport and structural stability of the WC/WP@NPC ternary *** synergistically lead to outstanding HER performances of the catalyst in acidic and alkaline *** finding offers a new strategy for designing Pt-alternative electrocatalysts with outstanding electrochemical performances for high-efficiency water splitting and other applications.

摘要：The exploration of efficient and earth‐rich electrocatalysts for electrochemical reactions is critical to the implementation of large‐scale green energy conversion and storage ***‐dimensional(2D)materials with distinctive structural and electrochemical properties provide fertile soil for researchers to harvest basic science and emerging applications,which can be divided into metal‐free materials(such as graphene,carbon nitride and black phosphorus)and transition metal‐based materials(such as halogenides,phosphates,oxides,hydroxides,and MXenes).For faultless 2D materials,they usually exhibit poor electrochemical hydrogen evolution reaction(HER)activity because only edge sites can be available while the base surface is chemically *** engineering is an effective strategy to generate active sites in 2D materials for improving electrocatalytic *** review presents feasible design strategies for constructing defect sites(including edge defects,vacancy defects and dopant derived defects)in 2D materials to improve their HER *** essential relationships between defect structures and electrocatalytic HER performance are discussed in detail,providing valuable guidance for rationally fabricating efficient HER *** hydrogen adsorption/desorption energy can be optimized by constructing defect sites at different locations and by adjusting the local electronic structure to form unsaturated coordination states for efficient HER.

摘要：The design and synthesis of high‐performance and low‐cost electrocatalysts for the hydrogen evolution reaction(HER),a key half‐reaction in water electrolysis,are *** to their modest hydrogen adsorption energy,ruthenium(Ru)‐based nanomaterials are considered outstanding candidates to replace the expensive platinum(Pt)‐based HER *** this study,we developed an adsorption‐pyrolysis method to construct nitrogen(N)‐doped graphene aerogel(N‐GA)‐supported ultrafine Ru nanocrystal(Ru‐NC)nanocomposites(Ru‐NCs/N‐GA).The particle size of the Ru‐NCs and the conductivity of the N‐GA substrate can be controlled by varying the pyrolysis *** experiments reveal revealed that 10 wt%Ru‐NCs/N‐GA nanocomposites require overpotentials of only 52 and 36 mV to achieve a current density of 10 mA cm^(−2) in 1 mol/L HClO4 and 1 mol/L KOH electrolytes for HER,respectively,which is comparable to 20 wt%Pt/C *** from the ultrafine size and uniform dispersion of the Ru‐NCs,the synergy between Ru and the highly conductive substrate,and the anchoring effect of the N atom,the Ru‐NCs/N‐GA nanocomposites exhibit excellent activity and durability in the pH‐universal HER,thereby opening a new avenue for the production of commercial HER electrocatalysts.

摘要：Single nanoparticle(NP)collisions technique has been widely employed in ***,the short collision duration of single NPs hinders the further improvement in their electrocatalytic ***,to increase the dynamic collision duration of single NPs in the electron tunneling region,enhanced near-wall hindered diffusion is introduced in the stochastic collision process by coupling a Au ultramicroelectrode(UME)with a confined *** the case of single palladium nanoparticle(Pd NP)collisions for the hydrogen evolution reaction(HER),the hydrodynamic trapping confined in the microchannel effectively permits the activation of the HER on the single Pd *** microchannel-based Au UME is promising in the application of single-NP collisions to energy conversion.

摘要：With the ever-pressing issues of global energy demand and environmental pollution,molecular hydrogen has been receiving increasing attention as a clean alternative energy *** hydrogen production,the design and development of high-performance catalysts remains rather *** the compositions and structures of catalyst interfaces have paramount influences on the catalytic performances,the central topic here has always been to design and engineer the interface structures via rational routes so as to boost the activities and stabilities of electrocatalysts on hydrogen evolution reaction(HER).Here in this review,we focus on the design and preparation of multi-scale catalysts specifically catering to HER *** start from the design and structure-activity relationship of catalytic nanostructures,summarize the research progresses related to HER nanocatalysts,and interpret their high activities from the atomistic perspective;then,we review the studies regarding the design,preparation,HER applications and structure-activity relationship of single-atom site catalysts(SASCs),and thereupon discuss the future directions in designing HER-oriented *** the end of this review,we present an outlook on the development trends and faced challenges of catalysts for electrochemical HER.

摘要：hydrogen is a promising sustainable energy to replace fossil fuels owning to its high specific energy and environmental *** water electrolysis has been considered as one of the most prospective technologies for large scale hydrogen *** boost the sluggish kinetics of hydrogen evolution reaction(HER)in alkaline media,abundant materials have been designed and ***,we summarize the key achievements in the development of layered transition-metal hydroxides[TM(OH)x]for efficient alkaline *** on the structure of TM(OH)x,the mechanism of synergistic effect between TM(OH)x and HER active materials is illuminated ***,recent progress of TM(OH)x-based HER catalysts to optimize the synergistic effect are categorized as TM(OH)x and active materials,including species,structure,morphology and interaction ***,TM(OH)x-based overall water splitting electrocatalysts and electrodes are summarized in the design principles for high activity and ***,some of key challenges for further developments and applications of hydrogen production are proposed.

摘要：Noble metal-free electrocatalysts with high activity are highly desirable for the large-scale application of hydrogen evolution reaction(HER). Mo_(2) C-based nanomaterials have been proved as a promising alternative to noble metal-based electrocatalysts owing to the Pt-resembled d-band density and optimal intermediates-adsorption ***, the aggregation and excessive growth of crystals often occur during their high-temperature synthesis procedure, leading to low catalytic utilization. In this study, the ultrafine Mo_(2) C/Mo_(2) N heterostructure with large surface and interface confined in the N-doped carbon nanofibers(NCNFs) was obtained by a melamine-assisted method. The synergistic effect of Mo_(2) C/Mo_(2) N heterostructure and plenty active sites exposed on the surface of ultrafine nanocrystals improves the electrocatalytic activity. Meanwhile, the N-CNFs ensure fast charge transfer and high structural stability during reactions. Moreover, the in-situ synthesis method strengthens the interfacial coupling interactions between Mo_(2)C/Mo_(2) N heterostructure and N-CNFs, further enhancing the electronic conductivity and electrocatalytic activity. Owing to these advantages, Mo_(2)C/Mo_(2) N@N-CNFs exhibit excellent HER performance with a low overpotential of 75 mV at a current density of 10 mV cm^(-2) in alkaline solution, superior to the single-phased Mo_(2)C counterpart and recently reported Mo_(2)C/Mo_(2) N-based catalysts. This study highlights a new effective strategy to design efficient electrocatalysts via integrating heterostructure, nanostructure and carbon modification.

摘要：The activation of multisite high-entropy alloy(HEA)electrocatalysts is helpful for improving the atomic utilization of each metal in water electrolysis ***,well-dispersed HEA nanocrystals on Nrich graphene with abundant M–pyridinic N–C bonds were synthesized through an ultrasonic-assisted confinement synthesis *** Raman analysis and density functional theory calculations revealed that the electrocatalysts presented the optimal electronic rearrangement with fast ratedetermined H_(2)O dissociation kinetics and favorable H^(*)adsorption behavior that greatly enhanced hydrogen generation in alkaline electrolyte.A small overpotential of only 138.6 mV was required to obtain the current density of 100 mA cm^(-2) and the Tafel slope of as low as 33.0 mV dec^(-1),which was considerably smaller than the overpotentials of the counterpart with poor M–pyridinic N–C bonds(290.4 mV)and commercial Pt/C electrocatalysts(168.6 mV).The atomic structure,coordination environment,and electronic structure were *** work provides a new avenue toward activating HEA as advanced electrocatalysts and promotes the research on HEA for energy-related electrolysis.

摘要：Alkaline water splitting is a promising technology for“green hydrogen”*** improve its efficiency,highly robust catalysts are required to reduce the overpotential for low electrical power *** modification is one of the most effective strategies for boosting catalytic performance,as it can regulate the physicochemical properties of host catalysts to improve their intrinsic ***,aiming to provide an overview of the impact of heteroatoms on catalytic activity at the atomic level,we present a review of the key role of heteroatoms in enhancing reaction kinetics based on the reaction pathways of the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in alkaline *** particular,the introduction of heteroatoms can directly and indirectly optimize the interactions between the active sites and intermediates,thus improving the intrinsic *** clearly illustrate this influence in detail,we have summarized a series of representative heteroatom-modified electrocatalysts and discussed the important roles of heteroatoms in the OER and HER reaction ***,some challenges and perspectives for heteroatom-modified electrodes are *** hope that this review will be helpful for the development of efficient and low-cost electrocatalysts for water electrolysis and other energy conversion applications.

摘要：Exploring and designing a high-performance non-noble metal catalyst for hydrogen evolution reaction(HER)are crucial for the large-scale application of H2 by water ***,novel catalysts with NiMo nanoparticles decorated on reduced graphene oxide(NiMo@r GO)synthesized by a two-step hydrothermal method were *** characterization results showed that the prepared NiMo@r GO-1 had an irregular lamellar structure,and the NiMo nanoparticles were uniformly dispersed on the ***@rGO-1 exhibited outstanding HER performance in an alkaline environment and required only 93 and 180 mV overpotential for HER in 1.0 M KOH solution to obtain current densities of-10 and-50 mA·cm^(-2),*** tests showed that NiMo@rGO-1 had a certain operating stability for32 *** the same condition,the performance of NiMo@rGO-1 can be comparable with that of commercial Pt/C catalysts at high current *** synergistic effect between NiMo particles and lamellate graphene can remarkably promote charge transfer in electrocatalytic *** a result,NiMo@rGO-1 presented the advantages of high intrinsic activity,large specific surface area,and small electrical *** lamellar graphene played a role in dispersion to prevent the aggregation of *** prepared NiMo@rGO-1 can be used in anion exchange membrane water electrolysis to produce *** study provides a simple preparation method for efficient and low-cost water electrolysis to produce hydrogen in the future.