| Abstract
| - A visible-light-responsive polycrystalline Bi12TiO20 photocatalyst was prepared using a simple solid-statereaction between Bi2O3 and TiO2 powders, and its photocatalytic activity under visible light irradiation forthe decomposition of methanol was investigated. The wavelength dependence of methanol decompositionproved that it is a photocatalytic reaction and that the photocatalytic activity of the photocatalyst is dominatedby its light absorption. A Bi12TiO20 sample prepared with a molar ratio of Bi2O3/TiO2 = 2 exhibited thehighest photoactivity among all prepared photocatalysts. After calcination at 600 °C, the band gap of thesample estimated from the onset of the absorption edge was about 2.78 eV. The hybridization of Bi 6s withO 2p in Bi12TiO20, which increases the mobility of the photogenerated carriers, may eliminate the recombinationcenter, resulting in the increase of the photocatalytic activity. In addition, the existence of two mixed cubiccrystalline Bi12TiO20 phases in this sample also possibly contributes to its high photocatalytic activity.
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