Effects of calcination temperature on the photocatalytic activity and photo-induced super-hydrophilicity of mesoporous TiO₂ thin films

Jiaguo YU, Jimmy C. YU, Wing Kei HO, Zitao JIANG

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248 Citations (Scopus)

Abstract

Mesoporous TiO₂ nanometer thin films were prepared on fused quartz by the dip-coating sol–gel method from a system containing a triblock copolymer as a template (or pore-forming agent), and then calcined at different temperatures. These films were characterized by X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, BET surface area and UV-visible spectrophotometry. The photocatalytic activity and photo-induced super-hydrophilicity of the films were evaluated by the photocatalytic degradation of acetone and water contact angle measurement in air, respectively. It was found that the thin films calcined at 700 °C not only show the highest photocatalytic activity, but also possess the greatest light-induced hydrophilicity and the slowest conversion rate from the hydrophilic to a hydrophobic state. The former is attributed to the fact that the films calcined at 700 °C are composed of anatase and rutile, which is beneficial in enhancing the transfer of photo-generated electrons from the anatase to the rutile phase, reducing the electron–hole combination rate in anatase and enhancing its activity. The high light-induced hydrophilicity and slow hydrophilic to hydrophobic conversion rate are due to the synergetic effect of good photocatalytic activity, sufficient surface hydroxyl content and a degree of surface roughness. Because of their high specific surface areas and mesoporous structures, the photocatalytic activity of mesoporous TiO₂ thin films is higher than that of conventional TiO₂ thin films. Copyright © 2002 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Original languageEnglish
Pages (from-to)607-613
JournalNew Journal of Chemistry
Volume26
Issue number5
DOIs
Publication statusPublished - 2002

Citation

Yu, J., Yu, J. C., Ho, W., & Jiang, Z. (2002). Effects of calcination temperature on the photocatalytic activity and photo-induced super-hydrophilicity of mesoporous TiO₂ thin films. New Journal of Chemistry, 26(5), 607-613. doi: 10.1039/b200964a

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