Two-dimensional(2D)transition metal dichalcogenides(TMDs)have proved to possess exceptional catalytic performance for hydrogen evolution and are considered to be an appropriate substitute for commercial Pt-based catal...Two-dimensional(2D)transition metal dichalcogenides(TMDs)have proved to possess exceptional catalytic performance for hydrogen evolution and are considered to be an appropriate substitute for commercial Pt-based catalysts.Experimentally,chemical vapor deposition(CVD)is an extremely important technique for acquiring controllable and high-purity TMDs for electrocatalysis and modern electronic devices.Recently,researchers have made significant achievements in synthesizing TMDs used for electrocatalytic hydrogen evolution by CVD ranging from dynamic mechanism exploration to performance optimization.In this review,we present the recent progress based on electrocatalytic hydrogen evolution implemented by CVDgrowth TMDs nanosheets and unveil the structural–activity correlation.Firstly,in synthesis,diverse factors covering precursor,substrate,temperature settings,and atmosphere will affect the quality and surface morphology of TMDs.Then,we present the current research status of the CVD-grown 2D TMDs for engineering electrocatalytic hydrogen evolution,including intrinsic performance exploring,morphology engineering,composition adjusting,phase engineering,and vertically-oriented structure constructing.Finally,the future prospects and challenges of CVD in 2D TMDs electrocatalysis are provided.展开更多
Nonmetal elements strictly govern the electrochemical performance of molybdenum compounds.Yet,the exact role played by nonmetals during electrocatalysis remains largely obscure.With intermetallic MoSi_2comprising sili...Nonmetal elements strictly govern the electrochemical performance of molybdenum compounds.Yet,the exact role played by nonmetals during electrocatalysis remains largely obscure.With intermetallic MoSi_2comprising silicene subunits,we present an unprecedented hydrogen evolution reaction(HER)behavior in aqueous alkaline solution.Under continuous operation,the HER activity of MoSi_2shows a more than one order of magnitude improvement in current density from 1.1 to 21.5 mA cm^(à2)at 0.4 V overpotential.Meanwhile,this activation behavior is highly reversible,such that voltage withdrawal leads to catalyst inactivation but another operation causes reactivation.Thus,the system shows dynamics strikingly analogous to the legendary Sisyphus’labor,which drops and recovers in a stepwise manner repeatedly,but never succeeds in reaching the top of the mountain.Isomorphic WSi_2behaves almost the same as MoSi_2,whereas other metal silicides with silicyne subunits,including CrSi_2and TaSi_2,do not exhibit any anomalous behavior.A thin amorphous shell of MoSi_2is observed after reaction,within which the Si remains partially oxidized while the oxidation state of Mo is basically unchanged.First-principles calculations further reveal that the adsorption of hydroxide ions on silicene subunit edges and the subsequent Si vacancy formation in MoSi_2jointly lead to the anomalous HER kinetics of the adjacent Mo active centers.This work demonstrates that the role of nonmetal varies dramatically with the electronic and crystallographic structures of silicides and that silicene structural subunit may serve as a promoter for boosting HER in alkaline media.展开更多
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDs)have proved to possess exceptional catalytic performance for hydrogen evolution and are considered to be an appropriate substitute for commercial Pt-based catalysts.Experimentally,chemical vapor deposition(CVD)is an extremely important technique for acquiring controllable and high-purity TMDs for electrocatalysis and modern electronic devices.Recently,researchers have made significant achievements in synthesizing TMDs used for electrocatalytic hydrogen evolution by CVD ranging from dynamic mechanism exploration to performance optimization.In this review,we present the recent progress based on electrocatalytic hydrogen evolution implemented by CVDgrowth TMDs nanosheets and unveil the structural–activity correlation.Firstly,in synthesis,diverse factors covering precursor,substrate,temperature settings,and atmosphere will affect the quality and surface morphology of TMDs.Then,we present the current research status of the CVD-grown 2D TMDs for engineering electrocatalytic hydrogen evolution,including intrinsic performance exploring,morphology engineering,composition adjusting,phase engineering,and vertically-oriented structure constructing.Finally,the future prospects and challenges of CVD in 2D TMDs electrocatalysis are provided.
基金financially supported by the National Natural Science Foundation of China (22071069 and 22275060)technical support from the Analytical and Testing Center at Huazhong University of Science and Technology。
基金supported by the National Key Research and Development Program of China (2016YFA0202603)the National Basic Research Program of China (2013CB934103)+3 种基金the Programme of Introducing Talents of Discipline to Universities (B17034)the National Natural Science Foundation of China (51521001, 51832004)the National Natural Science Fund for Distinguished Young Scholars (51425204)the Fundamental Research Funds for the Central Universities (WUT: 2017III008, 2017III009)
文摘Nonmetal elements strictly govern the electrochemical performance of molybdenum compounds.Yet,the exact role played by nonmetals during electrocatalysis remains largely obscure.With intermetallic MoSi_2comprising silicene subunits,we present an unprecedented hydrogen evolution reaction(HER)behavior in aqueous alkaline solution.Under continuous operation,the HER activity of MoSi_2shows a more than one order of magnitude improvement in current density from 1.1 to 21.5 mA cm^(à2)at 0.4 V overpotential.Meanwhile,this activation behavior is highly reversible,such that voltage withdrawal leads to catalyst inactivation but another operation causes reactivation.Thus,the system shows dynamics strikingly analogous to the legendary Sisyphus’labor,which drops and recovers in a stepwise manner repeatedly,but never succeeds in reaching the top of the mountain.Isomorphic WSi_2behaves almost the same as MoSi_2,whereas other metal silicides with silicyne subunits,including CrSi_2and TaSi_2,do not exhibit any anomalous behavior.A thin amorphous shell of MoSi_2is observed after reaction,within which the Si remains partially oxidized while the oxidation state of Mo is basically unchanged.First-principles calculations further reveal that the adsorption of hydroxide ions on silicene subunit edges and the subsequent Si vacancy formation in MoSi_2jointly lead to the anomalous HER kinetics of the adjacent Mo active centers.This work demonstrates that the role of nonmetal varies dramatically with the electronic and crystallographic structures of silicides and that silicene structural subunit may serve as a promoter for boosting HER in alkaline media.
