Visible-light-Induced photocatalytic degradation of azodyes in aqueous AgI/TiO2 dispersion.
Agl/Ti02 was prepared by the deposition-precipitation method and was found to be a novel visible light driven photocatalyst. The catalyst showed high efficiency for the degradation of the nonbiodegradable azodyes reactive red K-2G, reactive brilliant red X-3B, reactive red K-2BP, and reactive yellow KD-3G under visible light irradiation (lambda > 420 nm). The catalyst's activity was maintained effectively after successive cyclic experiments under visible irradiation without the destruction of AgI. On the basis of the characterization of X-ray diffraction, X-ray photoelectron spectroscopy, and Auger electron spectroscopy, the structure of AgI loaded on TiO2 did not significantly change before and after reaction. K-2G was completely decolorized and partly mineralized. The main intermediates are the small organic acids besides CO2 and cyanuric acid, which is photostable. The *OH is the main active oxygen species in the photocatalytic reaction by the studies of electron spin resonance and the effect of radical scavengers.
Hu
Chun
C
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. huchun@rceers.ac.cn
Hu
Xuexiang
X
Wang
Liusuo
L
Qu
Jiuhui
J
Wang
Aimin
A
D001391:Azo Compounds / Q000032:analysis*; D002384:Catalysis; D004396:Coloring Agents / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy; D007454:Iodides / Q000737:chemistry*; D008027:Light; D018030:Silver Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014867:Water
D001391:Azo Compounds; D004396:Coloring Agents; D007454:Iodides; D018030:Silver Compounds; D014867:Water; C009495:titanium dioxide; C030584:silver iodide; D014025:Titanium