Bi_(2)MoS_(2)O_(4)改性g-C_(3)N_(4)光催化降解罗丹明B

Bi_(2)MoS_(2)O_(4) modified g-C_(3)N_(4) photocatalytic degradation of Rhodamine B

为了降低石墨相氮化碳(g-C_(3)N_(4))电子空穴的复合率,采用浸渍法成功制备了Bi_(2)MoS_(2)O_(4)/g-C_(3)N_(4)异质结,并对其光催化性能进行了研究。紫外-可见漫反射光谱测得改性后的催化剂的吸收边由原来的470 nm红移至490 nm。探讨了负载比、催化剂投加量和pH对罗丹明B可见光降解率的影响。当Bi_(2)MoS_(2)O_(4)占gC_(3)N_(4)质量分数为18wt%、催化剂投加量为0.36 g/L时,该催化剂可在15 min内完全降解罗丹明B。自由基捕获实验和能带分析结果表明,该体系形成了一种Ⅱ型电子转移机制,其主要活性物种为•O_(2)^(−)。

In order to reduce the recombination rate of graphite phase carbon nitride(g-C_(3)N_(4))photocatalyst′s electron and holes,the Bi_(2)MoS_(2)O_(4)/g-C_(3)N_(4) heterojunction was successfully prepared by the impregnation method.The absorption edge of the modified catalyst is red-shifted from 470 nm to 490 nm as measured by ultravioletvisible diffuse reflectance spectroscopy.The effects of loading ratio,catalyst dosage and pH on the visible light degradation rate of Rhodamine B were discussed.When the mass ratio of Bi_(2)MoS_(2)O_(4) to g-C_(3)N_(4) is 18wt%and the catalyst dosage is 0.36 g/L,the catalyst can completely degrade Rhodamine B within 15 min.Free radical capture experiments and energy band analysis results show that the system has formed a type Ⅱ electron transfer mechanism,the main active species is·O_(2)^(−).