The development of an efficient artificial H_(2)O_(2) photosynthesis system is a challenging work using H_(2)O and O_(2) as starting materials.Herein,3D In_(2.77)S_(4) nanoflower precursor was in-situ deposited on K^(...The development of an efficient artificial H_(2)O_(2) photosynthesis system is a challenging work using H_(2)O and O_(2) as starting materials.Herein,3D In_(2.77)S_(4) nanoflower precursor was in-situ deposited on K^(+)-doped g-C_(3)N_(4)(KCN)nanosheets using a solvothermal method,then In_(2.77)S_(4)/KCN(IS/KCN)het-erojunction with an intimate interface was obtained after a calcination process.The investigation shows that the photocatalytic H_(2)O_(2) production rate of 50IS/KCN can reach up to 1.36 mmol g^(-1)h^(-1)without any sacrificial reagents under visible light irradiation,which is 9.2 times and 4.1 times higher than that of KCN and In_(2.77)S_(4)/respectively.The enhanced activity of the above composite can be mainly attributed to the S-scheme charge transfer route between KCN and In_(2.77)S_(4) according to density functional theory calculations,electron paramagnetic resonance and free radical capture tests,leading to an expanded light response range and rapid charge separation at their interface,as well as preserving the active electrons and holes for H_(2)O_(2) production.Besides,the unique 3D nanostructure and surface hydrophobicity of IS/KCN facilitate the diffusion and transportation of O_(2) around the active centers,the energy barriers of O_(2) protonation and H_(2)O_(2) desorption steps are ef-fectively reduced over the composite.In addition,this system also exhibits excellent light harvesting ability and stability.This work provides a potential strategy to explore a sustainable H_(2)O_(2) photo-synthesis pathway through the design of heterojunctions with intimate interfaces and desired reac-tion thermodynamics and kinetics.展开更多
In this study,a step-scheme photocatalytic system comprising one-dimensional In_(2)O_(3)nanorods and two-dimensional ZnIn_(2)S_(4)nanosheets was developed for the catalytic photofixation of nitrogen.The effects of the...In this study,a step-scheme photocatalytic system comprising one-dimensional In_(2)O_(3)nanorods and two-dimensional ZnIn_(2)S_(4)nanosheets was developed for the catalytic photofixation of nitrogen.The effects of the combination of In_(2)O_(3)with ZnIn_(2)S_(4)on the crystallinity,microstructure,optical absorption,and charge transfer behavior of the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts were investigated.Benefiting from the synergistic effects of the photogenerated vacancies and a step-scheme charge separation mechanism,the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalyst exhibited significantly enhanced catalytic activity compared to those of bare In_(2)O_(3)and pure ZnIn_(2)S_(4),and an optimized 50 wt%In_(2)O_(3)/ZnIn_(2)S_(4)hybrid sample was found to exhibit superior catalytic activity for the photofixation of N2,fixing 18.1±0.77 mg·L-1 of ammonia after exposure to simulated sunlight for 2 h.Crucially,the results of trapping experiments and electron paramagnetic resonance investigation to identify the active species confirmed that the catalytic nitrogen photofixation performance was highly correlated with the presence of·CO_(2)-radicals rather than photogenerated electrons,especially when methanol was used as a hole scavenger.In summary,the reported In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts exhibit both stability and high activity for the photofixation of N_(2),making them promising catalysts for sunlight-driven artificial N_(2)fixation.展开更多
文摘The development of an efficient artificial H_(2)O_(2) photosynthesis system is a challenging work using H_(2)O and O_(2) as starting materials.Herein,3D In_(2.77)S_(4) nanoflower precursor was in-situ deposited on K^(+)-doped g-C_(3)N_(4)(KCN)nanosheets using a solvothermal method,then In_(2.77)S_(4)/KCN(IS/KCN)het-erojunction with an intimate interface was obtained after a calcination process.The investigation shows that the photocatalytic H_(2)O_(2) production rate of 50IS/KCN can reach up to 1.36 mmol g^(-1)h^(-1)without any sacrificial reagents under visible light irradiation,which is 9.2 times and 4.1 times higher than that of KCN and In_(2.77)S_(4)/respectively.The enhanced activity of the above composite can be mainly attributed to the S-scheme charge transfer route between KCN and In_(2.77)S_(4) according to density functional theory calculations,electron paramagnetic resonance and free radical capture tests,leading to an expanded light response range and rapid charge separation at their interface,as well as preserving the active electrons and holes for H_(2)O_(2) production.Besides,the unique 3D nanostructure and surface hydrophobicity of IS/KCN facilitate the diffusion and transportation of O_(2) around the active centers,the energy barriers of O_(2) protonation and H_(2)O_(2) desorption steps are ef-fectively reduced over the composite.In addition,this system also exhibits excellent light harvesting ability and stability.This work provides a potential strategy to explore a sustainable H_(2)O_(2) photo-synthesis pathway through the design of heterojunctions with intimate interfaces and desired reac-tion thermodynamics and kinetics.
文摘In this study,a step-scheme photocatalytic system comprising one-dimensional In_(2)O_(3)nanorods and two-dimensional ZnIn_(2)S_(4)nanosheets was developed for the catalytic photofixation of nitrogen.The effects of the combination of In_(2)O_(3)with ZnIn_(2)S_(4)on the crystallinity,microstructure,optical absorption,and charge transfer behavior of the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts were investigated.Benefiting from the synergistic effects of the photogenerated vacancies and a step-scheme charge separation mechanism,the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalyst exhibited significantly enhanced catalytic activity compared to those of bare In_(2)O_(3)and pure ZnIn_(2)S_(4),and an optimized 50 wt%In_(2)O_(3)/ZnIn_(2)S_(4)hybrid sample was found to exhibit superior catalytic activity for the photofixation of N2,fixing 18.1±0.77 mg·L-1 of ammonia after exposure to simulated sunlight for 2 h.Crucially,the results of trapping experiments and electron paramagnetic resonance investigation to identify the active species confirmed that the catalytic nitrogen photofixation performance was highly correlated with the presence of·CO_(2)-radicals rather than photogenerated electrons,especially when methanol was used as a hole scavenger.In summary,the reported In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts exhibit both stability and high activity for the photofixation of N_(2),making them promising catalysts for sunlight-driven artificial N_(2)fixation.
