Preparation of Titanium−Silicon Binary Oxide Thin Film Photocatalysts by an Ionized Cluster Beam Deposition Method. Their Photocatalytic Activity and Photoinduced Super-Hydrophilicity

Abstract

Titanium−silicon binary oxide thin films of differing TiO2 content were prepared by using an ionized cluster beam (ICB) deposition method using multi-ion sources under a dry preparation process. From the results of UV−vis absorption measurements, binary oxide thin films with low TiO2 content showed much higher transmittance as compared with the pure TiO2 thin film, indicating that the Ti−oxide species of these Ti−Si binary oxide thin films exist in a highly dispersed state within the SiO2 matrices. Ti K-edge XAFS measurements revealed that such binary oxide thin films with low TiO2 content (less than 20%) showed only a sharp preedge peak attributed to the highly dispersed Ti−oxide species which are different from the peaks of anatase TiO2 thin films. Moreover, they were found to exhibit much higher and more efficient photocatalytic reactivity for the decomposition of NO into N2 and O2 under UV light irradiation than the pure TiO2 thin films.

Adhesion Strength of TiN Stacked TiO2 Film Correlated with Contact Angle, Critical Load, and XPS Spectra

“…However, as the light deactivates after 10 min, the contact angle continues increasing up to 12 degrees with the time delay of 20 minutes to light removal. Due to this characteristic of slight contact angle decrease with light irradiation and contact angle recovery with irradiation removal, it can be concluded that the film possesses photocatalytic properties [17].…”

Preparation of Highly Transparent TiO2-based Thin Film Photocatalysts by an Ion Engineering Method: Ionized Cluster Beam Deposition

“…The preparation of thin film materials in a high vacuum chamber have some potential advantages, as follows: (1) Contamination of the thin films with impurities can be prevented; (2) A dry preparation method does not require the use of any organic solvents so that it is an "environmentally-friendly process"; (3) Thin films with high crystallinity and strong adhesion can be easily prepared onto substrates without calcination at high temperatures; (4) The easy control of the various physical and chemical properties. We have successfully applied an ICB deposition method to prepare transparent TiO 2 -based thin films (Yamashita et al 1998a;Takeuchi et al 2000Takeuchi et al , 2001bTakeuchi et al , 2003aYamashita and Anpo 2004;Dohshi et al 2001;Anpo et al 2002). A schematic diagram of the ICB deposition method with multi ion-sources is shown in Fig.…”

“…2 (Fukushima et al 1985). In the ICB deposition method, titanium vapor obtained by heating titanium metal as a source (Takeuchi et al 2001b(Takeuchi et al , 2003aDohshi et al 2001;Anpo et al 2002). The TiO 2 /SiO 2 and TiO 2 /B 2 O 3 ratios, film thickness and deposition rate (ca.…”

“…Moreover, the BET surface areas and wavelengths of the absorption edge showed the same tendency toward photocatalytic reactivity. The optical properties of thin films such as the absorption edges and transparency in visible light regions are some of the most important factors that determine their photocatalytic reactivity (Takeuchi et al 2001b(Takeuchi et al , 2003aDohshi et al 2001;Anpo et al 2002). Figure 6 shows the UV-vis absorption (transmittance) spectra of the .…”

Gas-Phase Synthesis of Nanostructured Particulate Films

“…Cluster-beam deposition has been used to coat 10× 10 mm 2 glass substrates with Ti-Si binary oxide films for photocatalytic decomposition of NO under UV light radiation 56) . Zhou et al 57) used combined clusterbeam deposition and metal ion implantation to produce nanostructured vanadium-doped TiO2 films that showed photocatalytic decomposition of formic acid even under visible light radiation.…”