Photocatalytic decolorization of methylene blue dye by Ag3PO4–AgX (X = Cl−, Br− and I−) under visible light

Abstract

Three kinds of Ag3PO4–AgX (X=Cl−, Br− and I−) were prepared by the co-precipitation method between AgNO3 and Na2HPO4+KX (X=Cl−, Br− and I−) solutions. Their photocatalytic activities were also investigated by decolorization of a methylene blue solution. Under visible light irradiation, photocatalytic decolorization of the dye using Ag3PO4–AgX as photocatalyst could occur by interaction between a hole in the valence band of the photocatalyst and the methylene blue dye molecules as it cannot detect the emission of 7-hydroxylcoumarin. AgCl and AgBr induce the Ag3PO4 to increase its photocatalytic decolorization efficiency. On the other hand, the compound Ag3PO4–AgI also showed a high adsorption for methylene blue in the dark.