Five kinds of WSi_2/MoSi_2 composites were successfully prepared bymechanical alloying, IP and high temperature sintering techniques. And their hardness and fracturetoughness were measured by the Vickers indentation f...Five kinds of WSi_2/MoSi_2 composites were successfully prepared bymechanical alloying, IP and high temperature sintering techniques. And their hardness and fracturetoughness were measured by the Vickers indentation fracture mode through an Hv-10A type sclerometer.The microstructure and morphology were investigated by a JSM-56001V scanning electron microscope.Results show that the addition of 50% WSi_2 (in mole fraction) has remarkable hardening andtoughening effects on the MoSi_2 matrix, whose hardness value and fracture toughness value areincreased about 60% and 86%, respectively. For WSi_2/MoSi_2 composite, the hardening mechanisms arefine-grain and the second phase particles strengthening, and the toughening mechanisms includefine-grain, grain drawing, crack deflection, microbridge and bowing toughening.展开更多
Z-scheme heterojunction catalysts have received great attention due to their efficient ability to separate electrons and holes.Here,using the first-principles calculations,we designed a series of promising two-dimensi...Z-scheme heterojunction catalysts have received great attention due to their efficient ability to separate electrons and holes.Here,using the first-principles calculations,we designed a series of promising two-dimensional(2D)/2D Z-scheme systems with interlayer inequivalent,including MoSi_(2)N_(4)/MoSi_(2)N_(4),WSi_(2)N_(4)/WSi_(2)N_(4) and MoSi_(2)N_(4)/WSi_(2)N_(4).Molecular dynamics simulation and phonon dispersion show that they have sufficient environmental stability.The inequivalent structure between the layers caused the directional formation of built-in potentials,driving the transfer of net charge between layers,which greatly enhanced their catalytic activity.The smaller band gap and enhanced light absorption performance further revealed their perfect catalytic performance.Moreover,all they met the redox potential requirements of water splitting in a range of pH 0-7,demonstrate they are very remarkable photocatalysts for H_(2)evolution.More interestingly,they also have good sliding ferroelectricity,and the opposite built-in potential can be obtained by sliding between layers,which is very promising for future nanogenerators.Our works may provide new insights into energy conversion devices.展开更多
文摘Five kinds of WSi_2/MoSi_2 composites were successfully prepared bymechanical alloying, IP and high temperature sintering techniques. And their hardness and fracturetoughness were measured by the Vickers indentation fracture mode through an Hv-10A type sclerometer.The microstructure and morphology were investigated by a JSM-56001V scanning electron microscope.Results show that the addition of 50% WSi_2 (in mole fraction) has remarkable hardening andtoughening effects on the MoSi_2 matrix, whose hardness value and fracture toughness value areincreased about 60% and 86%, respectively. For WSi_2/MoSi_2 composite, the hardening mechanisms arefine-grain and the second phase particles strengthening, and the toughening mechanisms includefine-grain, grain drawing, crack deflection, microbridge and bowing toughening.
基金financially supported by the National Natural Science Foundation of China(Grant No.11764018)the Natural Science Foundation of Jiangxi Province(Grant No.20202ACBL211004)the Science and Technology Planning Project of Ganzhou City。
文摘Z-scheme heterojunction catalysts have received great attention due to their efficient ability to separate electrons and holes.Here,using the first-principles calculations,we designed a series of promising two-dimensional(2D)/2D Z-scheme systems with interlayer inequivalent,including MoSi_(2)N_(4)/MoSi_(2)N_(4),WSi_(2)N_(4)/WSi_(2)N_(4) and MoSi_(2)N_(4)/WSi_(2)N_(4).Molecular dynamics simulation and phonon dispersion show that they have sufficient environmental stability.The inequivalent structure between the layers caused the directional formation of built-in potentials,driving the transfer of net charge between layers,which greatly enhanced their catalytic activity.The smaller band gap and enhanced light absorption performance further revealed their perfect catalytic performance.Moreover,all they met the redox potential requirements of water splitting in a range of pH 0-7,demonstrate they are very remarkable photocatalysts for H_(2)evolution.More interestingly,they also have good sliding ferroelectricity,and the opposite built-in potential can be obtained by sliding between layers,which is very promising for future nanogenerators.Our works may provide new insights into energy conversion devices.
