Bi_(2)MoO_(6)修饰TiO_(2)复合纳米棒阵列光催化剂的制备及其光催化性能

Fabrication and photocatalyic performance of Bi_(2)MoO_(6) modified TiO_(2) nanorod array photocatalyst

为获得可回收的高效降解有机污染物光催化剂,采用水热/溶剂热二步法在TiO_(2)纳米棒阵列上修饰Bi_(2)MoO_(6)纳米片,合成了Bi_(2)MoO_(6)/TiO_(2)复合纳米棒阵列可见光催化剂。对Bi_(2)MoO_(6)/TiO_(2)光催化剂的形貌、结构、化学元素组成和光学性能进行分析,并借助电化学工作站测试了Bi_(2)MoO_(6)/TiO_(2)纳米棒阵列异质结构的光电化学性能和光催化性能,分析了光催化活性增强的机制。结果表明:较窄带隙的Bi_(2)MoO_(6)修饰TiO_(2)纳米棒阵列拓宽了光谱响应范围,促进了光生载流子的有效分离和转移,显著提高了亚甲基蓝的光催化降解效率;TiO_(2)和Bi_(2)MoO_(6)之间形成typeⅡ型异质结,Bi_(2)MoO_(6)/TiO_(2)的typeⅡ型能带结构与可见光的扩展吸收之间的协同作用是光催化性能提升的内在机制。

In order to obtain a recyclable photocatalyst for efficient degradation of organic pollutants under visible light,TiO_(2)nanorod arrays were modified with Bi_(2)MoO_(6)nanosheets by hydrothermal solvothermal two-step method to obtain Bi_(2)MoO_(6)/TiO_(2)composite.The morphology,structure,chemical element composition and optical properties of Bi_(2)MoO_(6)/TiO_(2)photocatalyst were analyzed,and the photoelectrochemical and photocatalytic properties of Bi_(2)MoO_(6)/TiO_(2)photocatalyst were tested with the help of electrochemical workstation in order to analyze the mechanism of enhanced photocatalytic activity.The results show that modification of TiO_(2)nanorod arrays by Bi_(2)MoO_(6)with narrow gap broadens the spectral response range,promotes the effective separation and transfer of photogenerated carriers,and obtains significantly enhanced photocatalytic degradation efficiency of methylene blue.The energy band structure diagram shows that type II heterojunction is formed between TiO_(2)and Bi_(2)MoO_(6),which promotes the separation and transfer of photogenerated electron holes.The synergistic effect between type II band structure of Bi_(2)MoO_(6)/TiO_(2)and the extended absorption of visible light is the internal mechanism for the improvement of photocatalytic properties.