以V_2O_5,AgNO_3和Y(NO_3)_3×6H_2O为原料、十二烷基苯磺酸钠为辅助剂,采用直接沉淀法和浸渍法制备单斜晶相Ag_3VO_4和Y_2O3_/Ag_3VO_4复合催化剂,表征了产物的结构和形貌,并分析了其形成机理;在可见光下研究了其催化可见光降解罗...以V_2O_5,AgNO_3和Y(NO_3)_3×6H_2O为原料、十二烷基苯磺酸钠为辅助剂,采用直接沉淀法和浸渍法制备单斜晶相Ag_3VO_4和Y_2O3_/Ag_3VO_4复合催化剂,表征了产物的结构和形貌,并分析了其形成机理;在可见光下研究了其催化可见光降解罗丹明B(Rh B)的性能.结果表明,所得Y_2O_3/Ag_3VO_4复合催化剂吸收边相对纯相Ag_3VO_4发生红移,禁带宽度减小至1.83 e V,电子-空穴对复合几率降低,对Rh B有较好的可见光催化活性和稳定性,可见光照射15 min后,0.08 g 3%Y2O_3/Ag_3VO_4催化200 m L 8 mg/L Rh B溶液的降解率达94.2%.展开更多
Ag3PO4/Ag/Ag2Mo2O7 composite photocatalyst was successfully prepared via an in situ precipitation method. The as-prepared Ag3PO4/Ag/Ag2Mo2O7 nanocomposite included Ag3PO4 nanoparticles （NPs） as well as Ag NPs assemb...Ag3PO4/Ag/Ag2Mo2O7 composite photocatalyst was successfully prepared via an in situ precipitation method. The as-prepared Ag3PO4/Ag/Ag2Mo2O7 nanocomposite included Ag3PO4 nanoparticles （NPs） as well as Ag NPs assembling on the surface of Ag2Mo2O7 nanowires. Under visible light irradiation （λ〉420 nm）, the Ag3PO4/Ag/Ag2Mo2O7 com- posite degraded rhodamine B （Rh B） efficiently and showed much higher photocatalytic efficiency than pure AgaPO4, Ag2Mo2O7, or Ag3PO4/Ag2Mo2O7. It was elucidated that the excellent photocatalytic performance of Ag3PO4/Ag/Ag2Mo2O7 for the degradation of Rh B under visible light could be ascribed to the high specific surface area, the extended absorption in the visible light region resulting from the Ag3PO4/Ag loading, and the effi- cient separation of photogenerated electrons and holes through the ternary heterostrucure composed of Ag3PO4, Ag and Ag2Mo2O7.展开更多
The properties of nanocrystals are highly dependent on their morphology, composition and structure. To obtain full control over their properties, the behavior of nanocrystals under external stimuli, such as heat treat...The properties of nanocrystals are highly dependent on their morphology, composition and structure. To obtain full control over their properties, the behavior of nanocrystals under external stimuli, such as heat treatment, needs to be understood. Herein, to in situ observe their microstructure and morphology changes, Fe3O4–Ag heterodimers were selected as a model system. Their structural changes after heat treatment were investigated by in situ transmission electron microscopy. A combination of real-time imaging with elemental analysis enabled observation of the transformation of Fe3O4–Ag heterodimers having a loose interface configuration to those with a Janus structure at the atomic scale after heating from room temperature to 600 °C. After incubation at 600 °C for 32 min, two kinds of Janus structures could be seen, including a clear linear interface in the Fe3O4–Ag heterodimers and a semi-crescent-shaped interface between the Ag and Fe3O4 nanoparticles(NPs). These dynamic observations provide unique insights into NP growth mechanisms, which are essential for understanding and controlling the structure and morphology of nanoparticles.展开更多
文摘以V_2O_5,AgNO_3和Y(NO_3)_3×6H_2O为原料、十二烷基苯磺酸钠为辅助剂,采用直接沉淀法和浸渍法制备单斜晶相Ag_3VO_4和Y_2O3_/Ag_3VO_4复合催化剂,表征了产物的结构和形貌,并分析了其形成机理;在可见光下研究了其催化可见光降解罗丹明B(Rh B)的性能.结果表明,所得Y_2O_3/Ag_3VO_4复合催化剂吸收边相对纯相Ag_3VO_4发生红移,禁带宽度减小至1.83 e V,电子-空穴对复合几率降低,对Rh B有较好的可见光催化活性和稳定性,可见光照射15 min后,0.08 g 3%Y2O_3/Ag_3VO_4催化200 m L 8 mg/L Rh B溶液的降解率达94.2%.
基金supported by the National Natural Science Foundation of China(No.21407059,No.21576112,No.21407064,and No.21607051)the Science Development Project of Jiangsu Province(BK20140527)+1 种基金the Science and Technology Research Project of the Department of Education of Jilin Province(No.2015220)the Open Subject of the State Key Laboratory of Rare Earth Resource Utilization(RERU2017011)
文摘Ag3PO4/Ag/Ag2Mo2O7 composite photocatalyst was successfully prepared via an in situ precipitation method. The as-prepared Ag3PO4/Ag/Ag2Mo2O7 nanocomposite included Ag3PO4 nanoparticles （NPs） as well as Ag NPs assembling on the surface of Ag2Mo2O7 nanowires. Under visible light irradiation （λ〉420 nm）, the Ag3PO4/Ag/Ag2Mo2O7 com- posite degraded rhodamine B （Rh B） efficiently and showed much higher photocatalytic efficiency than pure AgaPO4, Ag2Mo2O7, or Ag3PO4/Ag2Mo2O7. It was elucidated that the excellent photocatalytic performance of Ag3PO4/Ag/Ag2Mo2O7 for the degradation of Rh B under visible light could be ascribed to the high specific surface area, the extended absorption in the visible light region resulting from the Ag3PO4/Ag loading, and the effi- cient separation of photogenerated electrons and holes through the ternary heterostrucure composed of Ag3PO4, Ag and Ag2Mo2O7.
基金supported by the Natural Science Foundation of Hebei Province,China(B2014209182)Youth Foundation of Hebei Education Department,China(QN2014045)College Students'Innovative Entrepreneurial Training Plan Program of North China University of Science and Technology,China(X2015117)~~
文摘水热法结合原位沉淀法成功制备新型磁性溴化银/磷酸银/铁酸锌(AgBr/Ag_3PO_4/ZnFe_2O_4)复合催化剂,并通过X射线衍射、能量色散X射线、场发射扫描电子显微镜、透射电子显微镜和紫外-可见漫反射光谱对其晶相结构、组成、形貌及吸光性能进行了表征。在可见光照射下,所制备的AgBr/Ag_3PO_4/ZnFe_2O_4复合催化剂光催化降解罗丹明B(RhB)的活性优于Ag_3PO_4/ZnFe_2O_4、AgBr/ZnFe_2O_4和P25 TiO_2。在酸性和碱性溶液中,AgBr/Ag_3PO_4/ZnFe_2O_4光催化剂呈现出优良光催化性能。在AgBr/Ag_3PO_4/ZnFe_2O_4体系中,光催化降解Rh B的速率随着反应体系温度的升高而增大,由阿伦尼乌斯方程计算获得反应体系活化能为31.9 k J?mol^(-1)。AgBr/Ag_3PO_4/ZnFe_2O_4复合材料优异的可见光催化活性归因于光生电荷的有效分离,所产生的超氧自由基和空穴是Rh B降解的主要活性物种。
基金the Zhejiang Provincial Natural Science Foundation of China(No.LD19E010001)the National Natural Science Foundation of China(Nos.51771219,51771095 and 51771220)。
文摘The properties of nanocrystals are highly dependent on their morphology, composition and structure. To obtain full control over their properties, the behavior of nanocrystals under external stimuli, such as heat treatment, needs to be understood. Herein, to in situ observe their microstructure and morphology changes, Fe3O4–Ag heterodimers were selected as a model system. Their structural changes after heat treatment were investigated by in situ transmission electron microscopy. A combination of real-time imaging with elemental analysis enabled observation of the transformation of Fe3O4–Ag heterodimers having a loose interface configuration to those with a Janus structure at the atomic scale after heating from room temperature to 600 °C. After incubation at 600 °C for 32 min, two kinds of Janus structures could be seen, including a clear linear interface in the Fe3O4–Ag heterodimers and a semi-crescent-shaped interface between the Ag and Fe3O4 nanoparticles(NPs). These dynamic observations provide unique insights into NP growth mechanisms, which are essential for understanding and controlling the structure and morphology of nanoparticles.
