Efficient photocatalytic degradation of organics diluted in water and air using TiO2designed with zeolites and mesoporous silica materials

Titanium dioxide (TiO2) is a promising photocatalyst for degradation of organic compounds ideally under environmentally benign conditions. This paper reviews recent developments in designing TiO2-sorbent hybrid photocatalysts, especially those supported on ordered nano-porous silica materials including zeolites and mesoporous silicas, with the objective of fabricating efficient photodegradation systems toward organic compounds diluted in water and air. This review also describes the basic features of zeolites and mesoporous silica, adsorption kinetics on their surfaces, and the principles of surface modification techniques, and highlights that the hydrophobic nature of support materials can offer significant enhancement in photodegradation. Additionally, we note the several emerging synthetic approaches for related zeolitic materials from siliceous industrial wastes, which indicate the realization of energy-saving and recycling-oriented manufacturing processes in this field.