The development of non-noble-metal hydrogen evolution electrocatalysts holds great promises for a sustainable energy system.Here,a hybrid W(Mo)S_(2)/NW(Mo)C nanosheet with array structures was reported for an efficien...The development of non-noble-metal hydrogen evolution electrocatalysts holds great promises for a sustainable energy system.Here,a hybrid W(Mo)S_(2)/NW(Mo)C nanosheet with array structures was reported for an efficient light-as sis ted hydrogen evolution electrocatalysts in acidic solutions.The resulting vertically aligned W(Mo)S_(2)/N-W(Mo)C was supported on a conductive carbon fiber paper,which can be produced through annealing W(Mo)S_(2)nanosheets by simultaneous carbonization and N-doping in Ar/H_(2)atmosphere.This optimized WS_(2)/NWC and MoS_(2)/N-MoC electrode exhibits remarkable lightassisted electrocatalysis activity with overpotentials of0.120 and 0.122 V at 10 mA·cm^(-1)in acidic solutions,respectively.Such high hydrogen evolution activities should be attributed to the electrocatalytic synergistic effects of the abundant active sites existing in different phase boundaries and the absorption for ultraviolet-visible light.This study shows that synthesis of low-cost and highly active W(Mo)S_(2)-based hydrogen evolution electrocatalyst opens up a route toward the development of scalable production of hydrogen fuels.展开更多
In order to develop AlN composites suitable for high average power electronic tube, AlN-W materials were prepared by spark plasma sintering. The effects of manufacture parameters on dielectric loss tangent and permitt...In order to develop AlN composites suitable for high average power electronic tube, AlN-W materials were prepared by spark plasma sintering. The effects of manufacture parameters on dielectric loss tangent and permittivity constant were investigated, which include powder-mixed method, milling time of high-energy ball milling, starting powder particle size, sintering temperature and holding time and adding amount of the conductive second phase. The results showed that A1N-W materials sintered at the temperature of 1700℃ holding for 5 min with 10 vol.% W showed the best dielectric loss tangent larger than 0.81 at the frequency 1 kHz-1 MHz. In addition, magnetic stirring mixed powder and lower sintering temperature led to the better propelties because of the higher porosity. The samples sintered from the starting AlN powder with smaller particle size also had the better properties.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52202340)China Postdoctoral Science Foundation(No.2021M691365)+2 种基金the Applied Basic Research Project of Shanxi Province(No.20210302124425)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2021L266)the Graduate Science and Technology Innovation Project Foundation of Shanxi Normal University(No.2021XSY030)。
文摘The development of non-noble-metal hydrogen evolution electrocatalysts holds great promises for a sustainable energy system.Here,a hybrid W(Mo)S_(2)/NW(Mo)C nanosheet with array structures was reported for an efficient light-as sis ted hydrogen evolution electrocatalysts in acidic solutions.The resulting vertically aligned W(Mo)S_(2)/N-W(Mo)C was supported on a conductive carbon fiber paper,which can be produced through annealing W(Mo)S_(2)nanosheets by simultaneous carbonization and N-doping in Ar/H_(2)atmosphere.This optimized WS_(2)/NWC and MoS_(2)/N-MoC electrode exhibits remarkable lightassisted electrocatalysis activity with overpotentials of0.120 and 0.122 V at 10 mA·cm^(-1)in acidic solutions,respectively.Such high hydrogen evolution activities should be attributed to the electrocatalytic synergistic effects of the abundant active sites existing in different phase boundaries and the absorption for ultraviolet-visible light.This study shows that synthesis of low-cost and highly active W(Mo)S_(2)-based hydrogen evolution electrocatalyst opens up a route toward the development of scalable production of hydrogen fuels.
文摘In order to develop AlN composites suitable for high average power electronic tube, AlN-W materials were prepared by spark plasma sintering. The effects of manufacture parameters on dielectric loss tangent and permittivity constant were investigated, which include powder-mixed method, milling time of high-energy ball milling, starting powder particle size, sintering temperature and holding time and adding amount of the conductive second phase. The results showed that A1N-W materials sintered at the temperature of 1700℃ holding for 5 min with 10 vol.% W showed the best dielectric loss tangent larger than 0.81 at the frequency 1 kHz-1 MHz. In addition, magnetic stirring mixed powder and lower sintering temperature led to the better propelties because of the higher porosity. The samples sintered from the starting AlN powder with smaller particle size also had the better properties.
