Preparation and Characterization of TiO₂ Thin Films on Silica Gel Powders by Plasma Enhanced Chemical Vapor Deposition in a Circulating Fluidized Bed Reactor

Abstract

Plasma Enhanced Chemical Vapor Deposition (PECVD) of TiO₂ thin films on silica gel powders at atmospheric pressure in a Circulating Fluidized Bed (CFB) reactor was carried out. In addition, TiO₂ thin films on silica gel powders were prepared by the sol–gel method and compared with the TiO₂-deposited powders by PECVD. The characteristics of those thin films were determined by X-ray diffraction spectra, Raman spectroscopy, SEM and BET. Without heat treatment, anatase phase was crystallized well by PECVD in a CFB reactor. Specific surface area of the TiO₂-deposited silica gel by PECVD exhibits a larger value than that by the sol–gel method. By the PECVD method, TiO₂ thin films are uniformly deposited on the external surface of silica gel.