Two-dimensional layered MoS_(2) nanosheets are regarded as a promising catalyst for electrocatalytic hydrogen generation but suffer from limitations of catalytically inert basal planes and poor intrinsic conductivity....Two-dimensional layered MoS_(2) nanosheets are regarded as a promising catalyst for electrocatalytic hydrogen generation but suffer from limitations of catalytically inert basal planes and poor intrinsic conductivity.In this work,we report a simple hydrothermal method to synthesize defect-rich MoS_(2) nanosheets featuring vanadium(Ⅴ)doping,widely expanded interlayer spacings,and a high content of metallic 1T-phase towards the efficient hydrogen evolution reaction(HER).The structural characteristics of V(Ⅳ)&V(Ⅱ)co-doping,mixed 1T&2H phases and wide interlayer expansion endow the nanosheets with plentiful disorders and rich defects,thereby resulting in abundant active sites.Furthermore,V(Ⅳ)&V(Ⅱ)codoping brings in electronic benefits of a narrowed bandgap,improved intrinsic conductivity and optimized hydrogen adsorption free energy of basal planes.By tuning the V dopant content,the 10%V-MoS_(2) catalyst shows an optimized HER performance with a low overpotential of 146 mV at 10 mA cm^(−2) and a small Tafel slope of 48 mV dec^(−1),and a long operational stability of 80 h.Our work opens up new opportunities for improving the electrochemical HER performance of layered transition metal dichalcogenides(TMDs)by synergistic structural and compositional modulations.展开更多
Defect engineering of layered two-dimensional metal-dichalcogenide nanosheets is important for their promising application as an efficient and low-cost electrocatalyst towards hydrogen generation.In this work,metallic...Defect engineering of layered two-dimensional metal-dichalcogenide nanosheets is important for their promising application as an efficient and low-cost electrocatalyst towards hydrogen generation.In this work,metallic 1T-VS_(2) nanosheets featuring V^(2+)-doping and plenty of mesopores are synthesized and demonstrated as a superior hydrogen evolution reaction(HER)electrocatalyst.The V^(2+)-doped and mesoporous VS_(2) nanosheets are evolved from a VS_(2)·NH3 precursor by removing the intercalated NH3 molecules in an acid solution.V^(2+)-doping can significantly increase the vacancies and disorder of VS_(2) basal planes,while the mesopores can provide plenty of additional edge sites,thereby resulting in abundant defects as active catalytic sites.Owing to the synergistic effects of V^(2+)-doping,the mesoporous structure and metallic conductivity,the as-prepared V^(2+)-doped VS_(2) nanosheets work as a highly active catalyst for electrochemical water splitting.It delivers striking kinetic metrics of a very low onset potential of 19 mV and a small Tafel slope of 38 mV dec^(-1),which are much better than those of the pristine VS_(2) nanosheets without doping and mesopores.Furthermore,the V^(2+)-doped and mesoporous 1T-VS_(2) catalyst exhibits excellent long-term stability for 70 h.The present work paves a new way for synergistically increasing active catalytic sites of VS_(2) nanosheets towards an efficient HER.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51972092 and 51802145)the Natural Science Foundation of Anhui Province(No.1908085ME118)+2 种基金the Fundamental Research Funds for the Central Universities(No.PA2018GDQT0009)the Key Project of Natural Science Research in Anhui Colleges(No.KJ2020A0123)the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen(No.JCYJ20190809115413414).
文摘Two-dimensional layered MoS_(2) nanosheets are regarded as a promising catalyst for electrocatalytic hydrogen generation but suffer from limitations of catalytically inert basal planes and poor intrinsic conductivity.In this work,we report a simple hydrothermal method to synthesize defect-rich MoS_(2) nanosheets featuring vanadium(Ⅴ)doping,widely expanded interlayer spacings,and a high content of metallic 1T-phase towards the efficient hydrogen evolution reaction(HER).The structural characteristics of V(Ⅳ)&V(Ⅱ)co-doping,mixed 1T&2H phases and wide interlayer expansion endow the nanosheets with plentiful disorders and rich defects,thereby resulting in abundant active sites.Furthermore,V(Ⅳ)&V(Ⅱ)codoping brings in electronic benefits of a narrowed bandgap,improved intrinsic conductivity and optimized hydrogen adsorption free energy of basal planes.By tuning the V dopant content,the 10%V-MoS_(2) catalyst shows an optimized HER performance with a low overpotential of 146 mV at 10 mA cm^(−2) and a small Tafel slope of 48 mV dec^(−1),and a long operational stability of 80 h.Our work opens up new opportunities for improving the electrochemical HER performance of layered transition metal dichalcogenides(TMDs)by synergistic structural and compositional modulations.
基金financially supported by the National Natural Science Foundation of China(Grant No.51972092 and 51802145)the Fundamental Research Funds for the Central Universities(No.PA2018GDQT0009)the Natural Science Foundation of Guangdong Province(2018A030310225).
文摘Defect engineering of layered two-dimensional metal-dichalcogenide nanosheets is important for their promising application as an efficient and low-cost electrocatalyst towards hydrogen generation.In this work,metallic 1T-VS_(2) nanosheets featuring V^(2+)-doping and plenty of mesopores are synthesized and demonstrated as a superior hydrogen evolution reaction(HER)electrocatalyst.The V^(2+)-doped and mesoporous VS_(2) nanosheets are evolved from a VS_(2)·NH3 precursor by removing the intercalated NH3 molecules in an acid solution.V^(2+)-doping can significantly increase the vacancies and disorder of VS_(2) basal planes,while the mesopores can provide plenty of additional edge sites,thereby resulting in abundant defects as active catalytic sites.Owing to the synergistic effects of V^(2+)-doping,the mesoporous structure and metallic conductivity,the as-prepared V^(2+)-doped VS_(2) nanosheets work as a highly active catalyst for electrochemical water splitting.It delivers striking kinetic metrics of a very low onset potential of 19 mV and a small Tafel slope of 38 mV dec^(-1),which are much better than those of the pristine VS_(2) nanosheets without doping and mesopores.Furthermore,the V^(2+)-doped and mesoporous 1T-VS_(2) catalyst exhibits excellent long-term stability for 70 h.The present work paves a new way for synergistically increasing active catalytic sites of VS_(2) nanosheets towards an efficient HER.
