Preparation of Heterogeneous Photocatalyst (TiO2/Alumina) by Metallo-Organic Chemical Vapor Deposition

Abstract

The metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalyst titanium dioxide supported on porous alumina. Titanium tetraisopropoxide (TTIP) was used as the precursor, which was first deposited inside the mesopores of alumina under vacuum and then decomposed under controlled conditions to titanium dioxide. The amount of titanium dioxide deposited was found to be affected by the flow rate of the precursor and the methods of both deposition and decomposition. By using MOCVD, the number of steps in preparing porous media-supported catalyst can be reduced. X-ray diffraction results show that the heterogeneous photocatalyst produced by MOCVD has an anatase crystal structure. Alumina-supported titanium dioxide prepared by MOCVD method has a lower TiO2 content but has a catalytic efficiency similar to the commercial titanium dioxide powder Degussa P-25. The supported catalyst has an advantage in that it can easily be recovered from the treated water by filtration and is then ready for reuse.