TiO_2/Bi_2WO_6纳米异质结的制备及其可见光光催化性能

Preparation and Visible-light-driven Photocatalytic Performance of TiO_2/ Bi_2WO_6 Nano-heterostructure

采用共沉淀法制备了不同Ti/Bi摩尔比的TiO_2/Bi_2WO_6纳米异质结可见光光催化剂.采用XRD、HR-TEM、XPS及UV-vis DRS测试技术对样品的晶相结构、微观形貌、组成及吸光性能等进行了表征分析.以MB模拟环境污染物,考察了TiO_2/Bi_2WO_6纳米异质结的可见光光催化活性.结果表明,当热处理温度为700℃,n(Ti)∶n(Bi)的比值为1∶5.4,可见光照射180 min时,TiO_2/Bi_2WO_6纳米异质结对MB的降解率达80.0%,是纯Bi_2WO_6的12倍.光催化活性的提高可归因于TiO_2与Bi_2WO_6复合后可以产生能带交叠效应,从而促进光生电子-空穴对的有效分离.

TiOJBi2WO6 Nano-heterostructures with different Ti/Bi molar ratio were successfully prepared by a sim- ple co-precipitation method. The crystal structure, morphology, constitute and photo-absorbance of the obtained samples were characterized by XRD, HR-TEM, XPS and UV-vis DRS techniques. The photocatalytic performance of the TiO3/Bi2WO6 nano-heterostructure was evaluated by degradation of methylene blue （MB） solution under vis- ible light irradiation. Results indicated that when calcination 5.4, TiO2/Bi2WO6 can achieve the decomposition of pure Bi2WO6. The enhanced performance could promoted the effective separation of photogenerated temperature was 700 ℃ and n （Ti） ： n （Bi） = 1 of about 80.0% MB in 180 min, which was as 12 times as that be attributed to band overlap effect of TiO2 and Bi2WO6, which charges.