Visible Light Responsive Photocatalytic Degradation of 4-Chlorophenol on Neat TiO2 by Surface-Complex-Mediated Path

Abstract

The visible light responsive photocatalytic degradation of 4-chlorophenol was investigated in aqueous suspension of pure TiO₂ under visible light by a surface-complex-mediated path. The addition of tert-butyl alcohol, a common OH radical scavenger, did not affect the visible activity of 4-chlorophenol, which indicates that OH radicals are not responsible for the degradation. UV-Visible result indicated that the surface complexation between phenolic compounds and TiO₂ was formed, which was responsible for the visible light activity. The activity decreased dramatically after Pt deposition. The photocatalytic activity increased with increasing the S_BET of the catalyst. The crystal proportion of catalyst strongly influence the photocatalytic activity. The possible mechanism was investigated.