In this study, various transparent films were deposited on unheated glass-slide substrates by dc reactive sputtering technique. For one set of samples the ratio of Ar to was varied from 9:1 to 6:4 for a fixed sputtering pressure of , while for another set of samples the total working pressure was varied from for a fixed of 7:3. The crystallographic and optical properties of films were investigated in detail. The photocatalytic activity was evaluated by the measurement of decomposition of methanol under UV-visible irradiation. The structure of the films, prepared with various , varied from amorphous to different crystalline phases. Similarly sputtering pressure variation induced change of crystalline phase and crystallinity of films. The crystallinity improved greatly with decreasing sputtering pressure. The average transmittances of all of the films were almost constant for wavelengths in the range of for -varied thin films. The optical transmission edge of the films deposited at various sputtering pressure shifts toward low wavelength with higher sputtering pressure. The as-deposited films successfully photocatalyzed methanol to and , measured by Fourier transform infrared spectrometer. The decomposition efficiency of films increased with increasing sputtering pressure. However, the photocatalytic efficiency of films prepared at different did not show any regular dependence. The high photocatalytic activity of the sample prepared with at sputtering pressure of was tried to be explained by the effect of surface morphology and pure anatase crystalline phase.
Study of photocatalytic activity of thin films prepared in various ratio and sputtering gas pressure
S. Biswas, K. Prabakar, T. Takahashi, T. Nakashima, Y. Kubota, A. Fujishima; Study of photocatalytic activity of thin films prepared in various ratio and sputtering gas pressure. J. Vac. Sci. Technol. A 1 July 2007; 25 (4): 912–916. https://doi.org/10.1116/1.2717194
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