离子交换法制备AgBr/Ag2WO4复合催化剂及其可见光催化性能

摘要

以Ag2WO4为载体,采用离子交换法合成了新型的AgBr/Ag2WO4复合光催化剂.利用XRD、SEM和UV-Vis对AgBr/Ag2WO4催化剂进行了表征,在可见光条件下(500W、λ＞420 nm)、以甲基橙(MO)为染料模型研究了AgBr/Ag2WO4的光催化活性.结果表明,AgBr/Ag2WO4具有比单独的AgBr和Ag2WO4更佳的催化活性,其中30 ％-AgBr/Ag2WO4复合催化剂具有最大光催化活性.机理研究表明,在MO的降解过程中,·O2起主要作用,h+次之而·OH可以忽略.AgBr和Ag2WO4之间构成的异质结有效分离了光生电子和空穴,提高了催化剂的活性.%A novel AgBr/Ag2WO4 composite photocatalyst was synthesized by ion exchange of Ag2 WO4 substrate. AgBr/Ag2 WO4 was characterized by XRD,SEM and UV-Vis. The photocatalytic activity of AgBr/Ag2 WO4 was investigated with methyl orange (MO) as dye model under the visible light irradiation(500 W,A>420 nm). The results showed that AgBr/ Ag2 WO4 displayed much better photocatalytic activity than single AgBr and Ag2 WO4,in which 30%-AgBr/Ag2 WO4 sample showed the best photocatalytic activity. The mechanism results suggested that·O2~ played the major role,followed by h+ ,while ·OH could be negligible during the MO photodegradation process. The heteroj unction formed by AgBr and Ag2 WO4 was beneficial to efficiently separate the photogenerated electrons and holes and then raised the photocatalytic activity of AgBr/AgzWO4.