Bi2Sn2O7是一种特殊的烧绿石结构复杂氧化物,具有可见响应光催化性能,其带隙约为2.61 e V。采用水热法合成出棒状Bi2Sn2O7和颗粒组成的球形Bi2Sn2O7光催化材料,发现通过改变反应物的添加次序,可以产生不同的成核形式,从而导致产物的最...Bi2Sn2O7是一种特殊的烧绿石结构复杂氧化物,具有可见响应光催化性能,其带隙约为2.61 e V。采用水热法合成出棒状Bi2Sn2O7和颗粒组成的球形Bi2Sn2O7光催化材料,发现通过改变反应物的添加次序,可以产生不同的成核形式,从而导致产物的最终形貌不同。在可见光激发下,以罗丹明B为目标降解物进行了产物光催化性能的表征。由纳米颗粒组成的球状Bi2Sn2O7表现出更强的光催化性能,100 min时降解率达98%。通过光催化过程中的自由基淬灭反应,发现Bi2Sn2O7降解有机污染物的主要活性物种为超氧自由基和空穴。展开更多
本文采用水热法制备了γ-Bi_2Sn_2O_7并研究了其在可见光区的光电响应。Bi_2Sn_2O_7的晶体结构和光电响应特性分别用X射线衍射和表面光电压谱进行表征。研究结果表明,合成的Bi_2Sn_2O_7呈现γ相立方结构,通过吸收光谱估算光学带隙为2.67...本文采用水热法制备了γ-Bi_2Sn_2O_7并研究了其在可见光区的光电响应。Bi_2Sn_2O_7的晶体结构和光电响应特性分别用X射线衍射和表面光电压谱进行表征。研究结果表明,合成的Bi_2Sn_2O_7呈现γ相立方结构,通过吸收光谱估算光学带隙为2.67 e V,比α-Bi_2O_3(2.85 e V)的光学带隙小。Bi_2Sn_2O_7的光电响应相对于α-Bi_2O_3在可见光区展现出一定的优势,同时对外加电压有很强的响应。展开更多
The detailed theoretical studies of electronic,optical,and mechanical properties of γ-Bi2Sn2O7 are carried out by using first-principle density functional theory calculations.Our calculated results indicate that γ-B...The detailed theoretical studies of electronic,optical,and mechanical properties of γ-Bi2Sn2O7 are carried out by using first-principle density functional theory calculations.Our calculated results indicate that γ-Bi2Sn2O7 is the p-type semiconductor with an indirect band gap of about 2.72 e V.The flat electronic bands close to the valence band maximum are mainly composed of Bi-6s and O-2p states and play a key role in determining the electrical properties of γ-Bi2Sn2O7.The calculated complex dielectric function and macroscopic optical constants including refractive index,extinction coefficient,absorption coefficients,reflectivity,and electron energy-loss function show that γ-Bi2Sn2O7 is an excellent light absorbing material.The analysis on mechanical properties shows that γ-Bi2Sn2O7 is mechanically stable and highly isotropic.展开更多
To mitigate the water pollution problem by photocatalytic degradation of typical antibiotics of tetracycline(TC),we prepared defective Bi_(2)Sn_(2)O_7(BSO)quantum dots(QDs)with a full spectral response due to Bi metal...To mitigate the water pollution problem by photocatalytic degradation of typical antibiotics of tetracycline(TC),we prepared defective Bi_(2)Sn_(2)O_7(BSO)quantum dots(QDs)with a full spectral response due to Bi metal deposition,using a one-pot hydrothermal method,labeled as Bi@BSO-OV.The optimized Bi@BSOOV showed 73.4% removal of TC in 1 h under irradiation with a 50 W LED lamp in the wavelength band in the visible-near-infrared(vis-NIR)light,a rate that is substantially greater than that of pure BSO(14.7%).The synergistic interaction of Bi metal and oxygen vacancies(OVs)is crucial to boosting photocatalytic performance.The near-infrared region of the photo-response is extended by the surface plasmon resonance(SPR)effect of Bi metal,enhancing the photocatalytic performance and dramatically raising the efficiency of solar energy utilization.In addition to inducing defect levels in BSO,the OVs also activate the surface adsorbed O_(2) to promote the production of·O_(2)^(-)and ^(1)O_(2).DFT calculations reveal that Bi metal and OVs can mutually tune the charge transfer pathways.On the one hand,Bi metal can act as both a charge transfer bridge and an electron donor to assist charge separation.On the other hand,OVs-induced defect levels allow electrons that leap to the conduction band(CB)to first leap from the valence band(VB)to the defect levels,notably improving interfacial charge separation and transfer.The concept of design executed in this study for altering the catalyst by introducing both OVs and Bi metal can provide a rational design idea and potential insight for improving the photocatalytic activity for environmental applications.展开更多
文摘Bi2Sn2O7是一种特殊的烧绿石结构复杂氧化物,具有可见响应光催化性能,其带隙约为2.61 e V。采用水热法合成出棒状Bi2Sn2O7和颗粒组成的球形Bi2Sn2O7光催化材料,发现通过改变反应物的添加次序,可以产生不同的成核形式,从而导致产物的最终形貌不同。在可见光激发下,以罗丹明B为目标降解物进行了产物光催化性能的表征。由纳米颗粒组成的球状Bi2Sn2O7表现出更强的光催化性能,100 min时降解率达98%。通过光催化过程中的自由基淬灭反应,发现Bi2Sn2O7降解有机污染物的主要活性物种为超氧自由基和空穴。
文摘本文采用水热法制备了γ-Bi_2Sn_2O_7并研究了其在可见光区的光电响应。Bi_2Sn_2O_7的晶体结构和光电响应特性分别用X射线衍射和表面光电压谱进行表征。研究结果表明,合成的Bi_2Sn_2O_7呈现γ相立方结构,通过吸收光谱估算光学带隙为2.67 e V,比α-Bi_2O_3(2.85 e V)的光学带隙小。Bi_2Sn_2O_7的光电响应相对于α-Bi_2O_3在可见光区展现出一定的优势,同时对外加电压有很强的响应。
基金Project supported by the National Basic Research Program of China(Grant No.2014CB643703)the National Natural Science Foundation of China(Grant Nos.11164005,11464008,and 51401060)+1 种基金the Natural Science Foundation of Guangxi Zhuang Autonomous Region,China(Grant Nos.2014GXNSFGA118001 and 2012GXNSFGA060002)the Fund from Guangxi Provincial Key Laboratory of Information Materials of Guangxi Zhuang Autonomous Region,China(Grant Nos.1210908-215-Z and 131022-Z)
文摘The detailed theoretical studies of electronic,optical,and mechanical properties of γ-Bi2Sn2O7 are carried out by using first-principle density functional theory calculations.Our calculated results indicate that γ-Bi2Sn2O7 is the p-type semiconductor with an indirect band gap of about 2.72 e V.The flat electronic bands close to the valence band maximum are mainly composed of Bi-6s and O-2p states and play a key role in determining the electrical properties of γ-Bi2Sn2O7.The calculated complex dielectric function and macroscopic optical constants including refractive index,extinction coefficient,absorption coefficients,reflectivity,and electron energy-loss function show that γ-Bi2Sn2O7 is an excellent light absorbing material.The analysis on mechanical properties shows that γ-Bi2Sn2O7 is mechanically stable and highly isotropic.
基金financially supported by the Key Project of Natural Science Foundation of Tianjin(No.21JCZDJC00320)National Key R&D Program International Cooperation Project(No.2021YFE0106500)+1 种基金Tianjin Development Program for Innovation and EntrepreneurshipFundamental Research Funds for the Central Universities,Nankai University。
文摘To mitigate the water pollution problem by photocatalytic degradation of typical antibiotics of tetracycline(TC),we prepared defective Bi_(2)Sn_(2)O_7(BSO)quantum dots(QDs)with a full spectral response due to Bi metal deposition,using a one-pot hydrothermal method,labeled as Bi@BSO-OV.The optimized Bi@BSOOV showed 73.4% removal of TC in 1 h under irradiation with a 50 W LED lamp in the wavelength band in the visible-near-infrared(vis-NIR)light,a rate that is substantially greater than that of pure BSO(14.7%).The synergistic interaction of Bi metal and oxygen vacancies(OVs)is crucial to boosting photocatalytic performance.The near-infrared region of the photo-response is extended by the surface plasmon resonance(SPR)effect of Bi metal,enhancing the photocatalytic performance and dramatically raising the efficiency of solar energy utilization.In addition to inducing defect levels in BSO,the OVs also activate the surface adsorbed O_(2) to promote the production of·O_(2)^(-)and ^(1)O_(2).DFT calculations reveal that Bi metal and OVs can mutually tune the charge transfer pathways.On the one hand,Bi metal can act as both a charge transfer bridge and an electron donor to assist charge separation.On the other hand,OVs-induced defect levels allow electrons that leap to the conduction band(CB)to first leap from the valence band(VB)to the defect levels,notably improving interfacial charge separation and transfer.The concept of design executed in this study for altering the catalyst by introducing both OVs and Bi metal can provide a rational design idea and potential insight for improving the photocatalytic activity for environmental applications.
