A series of bi-based oxychlorides as efficient photocatalysts

A series of layered-structure Bi-based oxychlorides such as BiOCl, Bi ₃O₄Cl, Na_0.5Bi_1.5O₂Cl, Bi₄NbO₈Cl and MBiO₂Cl (M= Ca, Sr, Ba, Cd, Pb) used as efficient photocatalysts. Among them, Bi₃O₄Cl (E_g = 2.79eV),Na_0.5Bi_1.5O₂Cl (E _g = 3.03 eV), Bi₄NbO₈Cl(E_g = 2.38 eV)and PbBiO₂Cl (E_g = 2.45 eV) are visible-light- responsive. The powders synthesized by solid state reactions were characterized by X-ray diffraction (XRD) and UV-Vis diffuse reflection spectrum. Their photocatalytic activities were evaluated by the degradation of methyl orange. The results generally show that the UV-induced photocatalytic performances of the novel oxychloride catalysts are better than or comparable to that of anatase TiO₂. The high photocatalytic performance of Bi-based oxychlorides is mainly ascribed to the presence of strong internal static electric fields between layers.