Engineering the electronic properties of semiconductor-based photocatalysts using elemental doping is an effective approach to improve their catalytic activity.Nevertheless,there still remain contradictions regarding ...Engineering the electronic properties of semiconductor-based photocatalysts using elemental doping is an effective approach to improve their catalytic activity.Nevertheless,there still remain contradictions regarding the role of the dopants played in photocatalysis.Herein,ultrathin ZnIn_(2)S_(4)(ZIS) nanosheets with oxygen doping were synthesized by a one-pot solvothermal method.XRD,XPS and Raman spectral measurements support the presence of lattice oxygen in the oxygen-doped ZIS(O-ZIS) sample.With optimum doping of oxygen,the ultrathin O-ZIS nanosheets show enhanced CO_(2)-to-CO conversion activity with a CO_(2)-evolving rate of 1680 μmol h^(-1) g^(-1) under visible light irradiation,which is about 7 times higher than that of the pristine ZIS.First-principle calculations support that doping of oxygen in the lattice of ZnIn_(2)S_(4) nanosheets plays a key role in tuning its electronic properties.The remarkable photocatalytic performance of O-ZIS can be assigned to a synergistic consequence of a unique ultrathin-layered structure and an upward shift of the conduction band minimum(CBM) caused by the oxygen doping into ZIS and the quantum confinement effect(QCE) induced by the decreased particle size after doping as well as to the improved charge separation efficiency.The present work offers a simple elemental doping method to promote charge separation at atomic level and illustrates the roles played by oxygen doping in photocatalysis,giving new insights into highly efficient artificial photosynthesis.展开更多
Developing highly efficient S-scheme photocatalysts is a subject of immense interest for harnessing solar energy towards sustainable hydrogen production.Herein,a novel S-scheme heterojunction of oxygen vacancy-rich Co...Developing highly efficient S-scheme photocatalysts is a subject of immense interest for harnessing solar energy towards sustainable hydrogen production.Herein,a novel S-scheme heterojunction of oxygen vacancy-rich CoMoO_(4)/CN(CMO/CN)photocatalyst was rationally constructed through loading CoMoO_(4)nanorods on carbon nitride(CN)nanosheets via a direct one-pot calcination method.The CMO/CN S-scheme heterojunction exhibited enhanced surface area,fine CN dispersion,rich oxygen vacancies,and accelerated charge separation/transfer efficiency,which were conducive to improving photocatalytic H_(2)evolution performance.Of note,the optimal 3%CMO/CN sample displayed the highest H_(2)production rate of 8.35 mmol g^(-1)h^(-1),which is 4.6 folds that of pristine CN.In situ irradiated X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)characterizations confirmed the S-scheme charge transfer path between CN and CMO,which greatly promoted spatial charge separation.Density functional theory(DFT)calculations together with contact angle tests revealed the reduced activation energies for H_(2)O dissociation and enhanced hydrophilicity of the CMO/CN.The CMO/CN photocatalysts also presented high stability and fine reusability.This work may provide insights into the combination of defect engineering and heterojunction designing for high-efficiency solar-to-chemical energy conversion.展开更多
Urchin-like LaPO4 hollow spheres were successfully synthesized by a facile solution route using citric acid （CA） as a structure-directing agent. The size of the three-dimensional （3D） hollow spheres was tuned by c...Urchin-like LaPO4 hollow spheres were successfully synthesized by a facile solution route using citric acid （CA） as a structure-directing agent. The size of the three-dimensional （3D） hollow spheres was tuned by changing the concentration of CA. The formation mechanism of the 3D LaPO4 hollow spheres was revealed by studying the time-dependent morphology evolution process. Importantly, compared with monodispersed one-dimensional （1D） LaPO4 nanorods, the 3D LaPO4 hollow spheres self-assembled from nanorods showed a 6.8-fold enhancement in photocatalytic activity for CO2 reduction, which is attributed to the synergistic effect of their hierarchical hollow structure, higher light-harvesting capacity, and faster electron transfer. Our findings provide not only a simple, facile method for the synthesis of hierarchical hollow micro/nanoarchitectures but also an efficient route for enhancing the photocatalytic performance.展开更多
基金financially supported by the National Natural Science Foundation of China(Grants Nos.21976116 and 21902095)Shaanxi Science and Technology Program(2020KWZ005)+3 种基金SAFEA of China(High-end foreign expert project # G20190241013)Natural Foundation of Shaanxi Province(No.2020JQ-711)Group Linkage Program of Alexander-vonHumboldt Foundation of Germanythe scientific research startup fund of Shannxi University of Science and Technology。
文摘Engineering the electronic properties of semiconductor-based photocatalysts using elemental doping is an effective approach to improve their catalytic activity.Nevertheless,there still remain contradictions regarding the role of the dopants played in photocatalysis.Herein,ultrathin ZnIn_(2)S_(4)(ZIS) nanosheets with oxygen doping were synthesized by a one-pot solvothermal method.XRD,XPS and Raman spectral measurements support the presence of lattice oxygen in the oxygen-doped ZIS(O-ZIS) sample.With optimum doping of oxygen,the ultrathin O-ZIS nanosheets show enhanced CO_(2)-to-CO conversion activity with a CO_(2)-evolving rate of 1680 μmol h^(-1) g^(-1) under visible light irradiation,which is about 7 times higher than that of the pristine ZIS.First-principle calculations support that doping of oxygen in the lattice of ZnIn_(2)S_(4) nanosheets plays a key role in tuning its electronic properties.The remarkable photocatalytic performance of O-ZIS can be assigned to a synergistic consequence of a unique ultrathin-layered structure and an upward shift of the conduction band minimum(CBM) caused by the oxygen doping into ZIS and the quantum confinement effect(QCE) induced by the decreased particle size after doping as well as to the improved charge separation efficiency.The present work offers a simple elemental doping method to promote charge separation at atomic level and illustrates the roles played by oxygen doping in photocatalysis,giving new insights into highly efficient artificial photosynthesis.
基金supported by the National Natural Sci-ence Foundation of China(Grants Nos.22372095,21902095,and 21976116)the Young Talent Fund of the University Association for Science and Technology in Shaanxi(20210604)the SAFEA of China(High-end foreign expert project#G20190241013).
文摘Developing highly efficient S-scheme photocatalysts is a subject of immense interest for harnessing solar energy towards sustainable hydrogen production.Herein,a novel S-scheme heterojunction of oxygen vacancy-rich CoMoO_(4)/CN(CMO/CN)photocatalyst was rationally constructed through loading CoMoO_(4)nanorods on carbon nitride(CN)nanosheets via a direct one-pot calcination method.The CMO/CN S-scheme heterojunction exhibited enhanced surface area,fine CN dispersion,rich oxygen vacancies,and accelerated charge separation/transfer efficiency,which were conducive to improving photocatalytic H_(2)evolution performance.Of note,the optimal 3%CMO/CN sample displayed the highest H_(2)production rate of 8.35 mmol g^(-1)h^(-1),which is 4.6 folds that of pristine CN.In situ irradiated X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)characterizations confirmed the S-scheme charge transfer path between CN and CMO,which greatly promoted spatial charge separation.Density functional theory(DFT)calculations together with contact angle tests revealed the reduced activation energies for H_(2)O dissociation and enhanced hydrophilicity of the CMO/CN.The CMO/CN photocatalysts also presented high stability and fine reusability.This work may provide insights into the combination of defect engineering and heterojunction designing for high-efficiency solar-to-chemical energy conversion.
文摘Urchin-like LaPO4 hollow spheres were successfully synthesized by a facile solution route using citric acid （CA） as a structure-directing agent. The size of the three-dimensional （3D） hollow spheres was tuned by changing the concentration of CA. The formation mechanism of the 3D LaPO4 hollow spheres was revealed by studying the time-dependent morphology evolution process. Importantly, compared with monodispersed one-dimensional （1D） LaPO4 nanorods, the 3D LaPO4 hollow spheres self-assembled from nanorods showed a 6.8-fold enhancement in photocatalytic activity for CO2 reduction, which is attributed to the synergistic effect of their hierarchical hollow structure, higher light-harvesting capacity, and faster electron transfer. Our findings provide not only a simple, facile method for the synthesis of hierarchical hollow micro/nanoarchitectures but also an efficient route for enhancing the photocatalytic performance.
