Photocatalytic activity of a novel Bi-based oxychloride catalyst Na 0.5Bi 1.5O 2Cl

Abstract

A Bi-based oxychloride Na 0.5Bi 1.5O 2Cl 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 Na 0.5Bi 1.5O 2Cl has a smaller optical band gap of 3.04 eV than BiOCl ( E g = 3.44 eV). It possesses a fair visible-light-response ability. The UV-induced photocatalytic activity follows the decreasing order of BiOCl > Na 0.5Bi 1.5O 2Cl > TiO 2, different from the order of Na 0.5Bi 1.5O 2Cl > TiO 2 > BiOCl under visible light irradiation. The dispersion of Pt over Na 0.5Bi 1.5O 2Cl leads to an obvious increase in the photocatalytic performance. The internal electric fields between [Na 0.5Bi 1.5O 2] and [Cl] slabs favor the efficient separation of photostimulated electron–hole pairs.