Characterization of a TiO2 Photocatalyst Film Deposited by CVD and Its Photocatalytic Activity

Abstract

TiO 2 photocatalyst films were prepared by low-pressure metal±organic (LPMO) CVD, with varying reaction temperatures and deposition times, using titanium tetra-isopropoxide (TTIP). Firstly, the characteristics of the CVD preparation of TiO 2 films, as a function of the CVD reaction temperature and deposition time, were studied experimentally. Secondly, the photocatalytic activities of TiO 2 films were evaluated by the decomposition rate of methylene blue in aqueous solution using a photo-reactor. The results indicated that film thickness was linearly proportional to the deposition time. The structure of the film was strongly dependent on the reaction temperature and deposition time. Of the TiO 2 films grown, anatase and rutile showed the highest photocatalytic activity, whereas the amorphous TiO 2 films showed lower activities. The photocatalytic activity strongly depended on the film deposition time (or film thickness), but this was nonlinear. The optimum thickness of the TiO 2 catalyst film grown by LPMOCVD is located between 3 lm and 5 lm.

CVD of Thin Titanium Dioxide Films Using Hexanuclear Titanium Oxo Carboxylate Isopropoxides

“…[7] There is a significant interest in the synthesis of SiC nanostructures as novel functional materials for nanoscale engineering. [8,9,10] Recently, SiC films have been produced through a variety of methods such as plasma-enhanced (PE) CVD, [11] magnetron sputtering, [12,13] and ion-beam sputtering. [14] For example, Rao et al [15] produced SiC films by application of hybrid thermal plasma with an RF induction field superimposed on a DC arc jet.…”

Sol-Jel Yöntemiyle Hazırlanan TiO2 Filmlerin Optik ve Elektrokromik Özellikleri

“…TiO 2 ince filmler hazırlanırken RF saçtırma [20], ultrasonik sprey piroliz [21], kimyasal buhar depolama [22], darbeli lazer biriktirme [23], DC magnetron [24], sol-jel [25,26] gibi birçok ince film kaplama yöntemi kullanılmaktadır. Bu yöntemlerden biri olan sol-jel yöntemi, homojen yapı elde edilmesi, her aşamanın kontrol altında tutulabilmesi, basit cihazlar gerektirmesi ve düşük sıcaklıklarda uygulanabilir olması sebebiyle metal oksit kaplamalar hazırlamak için kullanışlı bir yöntemdir [27].…”

Effect of Thickness on Photocatalytic Activity of TiO2 Thin Films

“…During the last two decades, several methods have been developed to prepare TiO 2 thin films such as: electron beam evaporation [12], chemical vapor deposition [13,14], physical vapor deposition [15], atmospheric pressure chemical vapor deposition [16], and the sol-gel method [17]. Additionally, the sol-gel dip-coating process has been identified as one of the most appropriate techniques to prepare vitreous or polycrystalline films with excellent homogeneity, purity, and uniformity on any type of substrates.…”