Piezocatalysis and pyrocatalysis can achieve catalytic action with the application of external mechanical energy and varying temperatures.These catalytic processes have been widely applied in various fields,providing ...Piezocatalysis and pyrocatalysis can achieve catalytic action with the application of external mechanical energy and varying temperatures.These catalytic processes have been widely applied in various fields,providing innovative solutions to issues such as water pollution,energy shortages,and global warming.Despite the continuous breakthroughs in the catalytic performance of piezocatalysts and pyrocatalysts,powder-based catalysts face significant limitations due to their inability to be retrieved and the risk of secondary pollution,severely restricting their application.Methods such as compression molding,3 D printing,and the preparation of ceramic-polymer bulk composites can effectively address the issue of catalyst retrievability.However,bulk catalysts,which lose a significant amount of surface area,still need their catalytic performance further enhanced.Therefore,achieving piezocatalysts and pyrocatalysts with excellent catalytic performance and retrievability is of increasing importance.展开更多
Piezocatalytic materials have been widely used for catalytic hydrogen evolution and purification of organic contaminants.However,most studies focus on nano-size and/or polycrystalline catalysts,suffering from aggregat...Piezocatalytic materials have been widely used for catalytic hydrogen evolution and purification of organic contaminants.However,most studies focus on nano-size and/or polycrystalline catalysts,suffering from aggregation and neutralization of internal piezoelectric field caused by polydomains.Here we report a single crystal ZnO of large size and few bulk defects crafted by a hydrothermal method for piezocatalytic hydrogen generation from pure water.It is noteworthy that single-side surface areas of both original as-prepared ZnO and Ga-doped ZnO bulk crystals are larger than 30 cm^(2).The high quality of ZnO and Ga-doped ZnO bulks are further uncovered by high-resolution transmission electron microscope(HRTEM),photoluminescence(PL)and X-ray diffraction(XRD).Remarkably,an outstanding hydrogen production rate of co-catalyst-free Ga-doped ZnO bulk crystal(i.e.,a maximum rate of 5915μmol h^(-1) m^(-2))is observed in pure water triggered by ultrasound in dark,which is over 100 times higher than that of its powder counterpart(i.e.,52.54μmol h^(-1) m^(-2)).The piezocatalytic performance of ZnO bulk crystal is systematically studied in terms of varied exposed crystal facet,thickness and conductivity.Different piezocatalytic performances are attributed to magnitude and distribution of piezoelectric potential,revealed by the finite element method(FEM)simulation.The density functional theory(DFT)calculations are employed to investigate the piezocatalytic hydrogen evolution process,indicating a strong H_(2)O adsorption and a low energy barrier for both H_(2)O dissociation and H2 generation on the stressed Znterminated(0001)ZnO surface.展开更多
基金Project(2022YFB3807404)supported by the National Key Research and Development Program of ChinaProject(52302158)supported by the National Natural Science Foundation of China。
文摘Piezocatalysis and pyrocatalysis can achieve catalytic action with the application of external mechanical energy and varying temperatures.These catalytic processes have been widely applied in various fields,providing innovative solutions to issues such as water pollution,energy shortages,and global warming.Despite the continuous breakthroughs in the catalytic performance of piezocatalysts and pyrocatalysts,powder-based catalysts face significant limitations due to their inability to be retrieved and the risk of secondary pollution,severely restricting their application.Methods such as compression molding,3 D printing,and the preparation of ceramic-polymer bulk composites can effectively address the issue of catalyst retrievability.However,bulk catalysts,which lose a significant amount of surface area,still need their catalytic performance further enhanced.Therefore,achieving piezocatalysts and pyrocatalysts with excellent catalytic performance and retrievability is of increasing importance.
基金the financial support from the National Natural Science Foundation of China(No.21905317)the financial support from the National Natural Science Foundation of China(No.91833301)the Youth Talent Promotion Project from China Association for Science and Technology。
文摘Piezocatalytic materials have been widely used for catalytic hydrogen evolution and purification of organic contaminants.However,most studies focus on nano-size and/or polycrystalline catalysts,suffering from aggregation and neutralization of internal piezoelectric field caused by polydomains.Here we report a single crystal ZnO of large size and few bulk defects crafted by a hydrothermal method for piezocatalytic hydrogen generation from pure water.It is noteworthy that single-side surface areas of both original as-prepared ZnO and Ga-doped ZnO bulk crystals are larger than 30 cm^(2).The high quality of ZnO and Ga-doped ZnO bulks are further uncovered by high-resolution transmission electron microscope(HRTEM),photoluminescence(PL)and X-ray diffraction(XRD).Remarkably,an outstanding hydrogen production rate of co-catalyst-free Ga-doped ZnO bulk crystal(i.e.,a maximum rate of 5915μmol h^(-1) m^(-2))is observed in pure water triggered by ultrasound in dark,which is over 100 times higher than that of its powder counterpart(i.e.,52.54μmol h^(-1) m^(-2)).The piezocatalytic performance of ZnO bulk crystal is systematically studied in terms of varied exposed crystal facet,thickness and conductivity.Different piezocatalytic performances are attributed to magnitude and distribution of piezoelectric potential,revealed by the finite element method(FEM)simulation.The density functional theory(DFT)calculations are employed to investigate the piezocatalytic hydrogen evolution process,indicating a strong H_(2)O adsorption and a low energy barrier for both H_(2)O dissociation and H2 generation on the stressed Znterminated(0001)ZnO surface.
