Preparation of heterogeneous photocatalyst (TiO2/alumina) by metallo-organic chemical vapor deposition

The metallo-organic chemical vapor deposition (MOCVD) technique has been ap plied to the preparation of the photocatalyst titanium dioxide supported on porous alumina. Titanium tetraisopropoxide (TTIP) was used as the precurso r, which was first deposited inside the mesopores of alumina under vacuum a nd then decomposed under controlled conditions to titanium dioxide. The amo unt 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 cataly st can be reduced. X-ray diffraction results show that the heterogeneous ph otocatalyst produced by MOCVD has an anatase crystal structure. Alumina-sup ported titanium dioxide prepared by MOCVD method has a lower TiO2 content b ut has a catalytic efficiency similar to the commercial titanium dioxide po wder Degussa P-25. The supported catalyst has an advantage in that it can e asily be recovered from the treated water by filtration and is then ready f or reuse.