Photodegradation of rhodamine B and methyl orange by Ag3PO4 catalyst under visible light irradiation

Abstract

A visible-light-driven Ag3PO4 catalyst was successfully synthesized by a facile ion-exchange route. The as-synthesized Ag3PO4 was characterized by X-Ray diffraction (XRD), field-emission scanning electron microscopy, N2 adsorption-desorption, UV-Vis diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy. Under visible light irradiation, the Ag3PO4 catalyst showed excellent photocatalytic activity for rhodamine (RhB) degradation, but was poor at degrading methyl orange (MO) because of lower adsorption of MO molecules onto the surface of the Ag3PO4. The photodegradation of RhB and MO was achieved by holes and O2•− radical attack in the Ag3PO4 suspension. The photodegradation of MO over the Ag3PO4 catalyst was greatly enhanced in the presence of RhB owing to greater production of O2•− radicals.