采用水热法制备Bi2WO6-BiPO4异质结光催化剂.利用模拟太阳光照射下的罗丹明B降解实验评价了Bi2WO6-BiPO4复合物的光催化性能.结果表明,Bi2WO6-BiPO4光催化活性比Bi2WO6和BiPO4高得多.当Bi2WO6与BiPO4的摩尔比为1:1时复合光催化剂对罗丹明B的降解率最高.Bi2WO6-BiPO4催化活性增强主要归结为两者之间形成了有效的异质结结构,其内建电场能够促进光生载流子的分离.同时,Bi2WO6的加入增强了其对可见光的吸收.研究表明O2^· -和h^+在光催化降解过程中是主要的活性物种.
Novel Bi2WO6-BiPO4 photocatalysts with heterojunction structure were fabricated through a facile hydrothermal route. The photocatalytic properties of Bi2WO6-BiPO4 composites were evaluated by photocatalytic degradation of rhodamine B (Rh B) under simulated sunlight irradiation. The results showed that Bi2WO6-BiPO4 photocatalysts displayed much higher photocatalytic performances for Rh B degradation than the single BiPO4 and Bi2WO6. The best photocatalytic activity of Bi2WO6-BiPO4 with nearly 100% Rh B degradation located at molar ratio of 1:1 after 20 min irradiation. The enhanced photo-catalytic performance could be mainly ascribed to the formation of heterojunction interface in Bi2WO6-BiPO4 which facilitated the transfer and separation of photogenerated electron-hole pairs, as well as the strong visible light absorption originating from the sensitization role of Bi2WO6 to BiPO4. It was also found that the photodegradation of Rh B molecules was mainly attributed to the oxidation action of the generated O2^· - radicals and partly to the action of hvb^+ via direct hole oxidation process.