Sulfanilic acid-modified P25 TiO2 nanoparticles with improved photocatalytic degradation on Congo red under visible light

Visible-light-induced titania/sulfanilic acid nano-composite photocatalysts were prepared and characterized by FTIR, XPS, UV-vis, XRD, and SEM. The results indicate that the formation of Ti-O-S bonds after the modification of P25 TiO2 nanoparticles with sulfanilic acid ligands extends the photoresponse of the photocatalyst from the UV to the visible range. The photocatalytic activity of the nano-composite photocatalyst was examined by degrading Congo red under visible light, in which its effecting factors such as irradiation time, catalyst dosage, solution pH and the addition of H2O2, were investigated in detail. The possible mechanism of photocatalytic degradation under visible irradiation has been also presented. (C) 2011 Elsevier Ltd. All rights reserved.