Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be exte...Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be extended to further enhance their photocatalytic activity for H_(2)evolution.Herein,we present a successful attempt to selectively dope lanthanide ions into the{101}facets of ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets through a facile one-step solvothermal method.The lanthanide doping slightly extended the light-harvesting region and markedly improved the charge-separated states of the TiO_(2)nanosheets as evidenced by UV-vis absorption and steady-state/transient photoluminescence spectra.Upon simulated sunlight irradiation,we observed a 4.2-fold enhancement in the photocatalytic H_(2)evolution activity of optimal Yb^(3+)-doped TiO_(2)nanosheets compared to that of their undoped counterparts.Furthermore,when Pt nanoparticles were used as cocatalysts to reduce the H_(2)overpotential in this system,the photocatalytic activity enhancement factor increased to 8.5.By combining these results with those of control experiments,we confirmed that the extended charge-separated states play the main role in the enhancement of the photocatalytic H_(2)evolution activity of lanthanide-doped TiO_(2)nanosheets with coexposed{001}/{101}facets.展开更多
Unusual designated-tailoring on the preferential growth of ZnO meso-/nanocrystals with different shapes and sizes was successfully achieved through a very facile precursor-hydrolysis process in a water/organic solvent...Unusual designated-tailoring on the preferential growth of ZnO meso-/nanocrystals with different shapes and sizes was successfully achieved through a very facile precursor-hydrolysis process in a water/organic solvent system.The shape-evolution of ZnO from mesocrystal to nanocrystal was achieved by increasing the amount of water in the reaction system under otherwise the same conditions,which can be attributed to selective-capping and preferential growth mechanisms based on DFT calculations.展开更多
文摘Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be extended to further enhance their photocatalytic activity for H_(2)evolution.Herein,we present a successful attempt to selectively dope lanthanide ions into the{101}facets of ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets through a facile one-step solvothermal method.The lanthanide doping slightly extended the light-harvesting region and markedly improved the charge-separated states of the TiO_(2)nanosheets as evidenced by UV-vis absorption and steady-state/transient photoluminescence spectra.Upon simulated sunlight irradiation,we observed a 4.2-fold enhancement in the photocatalytic H_(2)evolution activity of optimal Yb^(3+)-doped TiO_(2)nanosheets compared to that of their undoped counterparts.Furthermore,when Pt nanoparticles were used as cocatalysts to reduce the H_(2)overpotential in this system,the photocatalytic activity enhancement factor increased to 8.5.By combining these results with those of control experiments,we confirmed that the extended charge-separated states play the main role in the enhancement of the photocatalytic H_(2)evolution activity of lanthanide-doped TiO_(2)nanosheets with coexposed{001}/{101}facets.
基金supported by the National Science Foundation of China(NSFC No.U1502274,51302213,51471132 and 51202191)the National High Technology Research and Development Program of China(863 Program,No.2015AA034304)+1 种基金the Pivot Innovation Team of Shaanxi Electric Materials and Infiltration Technique(2012KCT-25)the Hundred Talent Program of Shaanxi Province,and the Shaanxi Province Science Fund for Distinguished Young Scholars(2018JC-027).The authors thank Mr Haoqi Ren for the suggestions in revision.
文摘Unusual designated-tailoring on the preferential growth of ZnO meso-/nanocrystals with different shapes and sizes was successfully achieved through a very facile precursor-hydrolysis process in a water/organic solvent system.The shape-evolution of ZnO from mesocrystal to nanocrystal was achieved by increasing the amount of water in the reaction system under otherwise the same conditions,which can be attributed to selective-capping and preferential growth mechanisms based on DFT calculations.
