Photocatalytic property of bismuth titanate Bi12TiO20 crystals

Bi(12)TiO(20) crystals with sillenite structures were prepared by a chemical solution decomposition (CSD) method. The band gap of Bi(12)TiO(20) crystals was estimated to be about 2.4 eV from the onset of UV-Vis absorption spectra of the photocatalyst. The energy band of Bi(12)TiO(20) is assumed to between the top of Bi(3+) 6s band and the bottom of the Ti 3d band. The photocatalyst based on Bi(12)TiO(20) crystals for photo-decolorization of methyl orange had been examined first. Bi(12)TiO(20) crystals show high photocatalystic activity to photo-decolorization 10 ppm methyl orange solution in 1.5 h. Bi-O polyhedra in Bi(12)TiO(20) crystals were assumed to facilitate the photocatalystic activity of the catalysts. (C) 2002 Elsevier Science B.V. All rights reserved.