Photocatalytic activity of a novel Bi-based oxychloride catalyst Na0.5Bi1.5O2Cl

A Bi-based oxychloride Na0.5Bi1.5O2Cl with a layered structure as a novel efficient photocatalyst was studied in the present paper. The powder was synthesized by a solid state reaction method. It was characterized by X-ray diffraction, scanning electron microscope and UV-vis diffuse reflectance spectrum. Degradation of methyl orange was used to evaluate the photocatalytic activity. The as-synthesized Na0.5Bi1.5O2Cl has a smaller optical band gap of 3.04 eV than BiOCI (E-g = 3.44 eV). It possesses a fair visible-light-response ability. The UV-induced photocatalytic activity follows the decreasing order of BiOCI > Na0.5Bi1.5O2Cl > TiO2, different from the order of Na0.5Bi1.5O2Cl > TiO, > BiOCl under visible light irradiation. The dispersion of Pt over Na0.5Bi1.5O2Cl leads to an obvious increase in the photocatalytic performance. The internal electric fields between [Na0.5Bi1.52]and [Cl] slabs favor the efficient separation of photostimulated electron-hole pairs. (c) 2007 Elsevier Masson SAS. All rights reserved.