Tailored titanium dioxide photocatalysts for the degradation of organic dyes in wastewater treatment: A review

Organic dyes are one of the largest groups of pollutants released into wastewaters from textile and other industrial processes. Because of potential toxicity of the dyes and their visibility in surface waters, removal and degradation of organic dyes have been a matter of considerable interest. A wide range of methods have been developed, amongst which the heterogeneous photocatalysis involving titanium dioxide (TiO2) appears to be the most promising technology. This paper presents a critical review of novel achievements in the modification of TiO2 photocatalytic systems aimed at: enhanced TiO2 photocatalytic efficiency; complete mineralization of organic dyes; efficient utilization of visible and/or solar light: stability and reproducibility of the modified TiO2; recycle and reuse in real wastewater treatment. (C) 2009 Elsevier B.V. All rights reserved.