Preparation and characterisation of mesoporous TiO2 photo-catalyst

Abstract

Photo-catalytic oxidation with TiO2 as the photo-catalyst is one of the most efficient methods of advanced oxidation for the degradation of organic pollutants. It can completely oxidise many of the persistent organic pollutants into small molecules such as H2O and CO2. However, a number of factors currently limit the large-scale adaptation of the technology in industries. The catalytic activity of TiO2 is normally only effective in the UV irradiation range and it has been difficult to utilise irradiations in higher wavelengths. The immobilisation of the catalyst for large-scale operations has also been difficult and reduces the efficiency of the photo-oxidation reactions. Nanometer particles of TiO2 are highly photo-effective but difficult to recover and reuse. In this paper, mesoporous TiO2 catalyst with an average pore size of 5 nm was prepared by using a tartaric sol-gel method with cetyl trimethyl ammonium bromide as template agent. UV irradiation was also applied during the preparation process to modify the surface characteristics of the photo-catalyst. The catalyst was then analysed and characterised by using a number of techniques. Results indicated that UV irradiation during the preparation process of the mesoporous TiO2 catalyst changed its surface characteristics. It was observed that the UV irradiated TiO2 catalyst has higher absorbance in the visible wavelength region (400-650 nm), indicating a potential shift of the effective photo-catalytic wavelengths.