Highly efficient photodegradation of RhB–MO mixture dye wastewater by Ag3PO4 dodecahedrons under acidic condition

Abstract

We report the photodegradation of rhodamine B (RhB), methyl orange (MO) and their mixture solutions at different pH values by the Ag3PO4 dodecahedrons, which are synthesized by a simple precipitation method at room temperature. The samples are characterized by X-ray diffraction spectra (XRD), scanning electron microscope (SEM) and UV–vis diffuse-reflection spectra (UV-DRS). The contrast experiments, in which dimethyl sulfoxide (DMSO) is added as the scavenger of ·OH, confirm that the addition of acid favors the formation of more ·OH free radicals. As a result, the higher degradation efficiency can be achieved under acidic condition than under alkaline and neutral conditions for RhB, MO and their mixture dyes. Furthermore, the Ag3PO4 dodecahedrons also show a high visible-light degradation activity for the RhB–MO mixture dye solution, in which the degradation efficiency of MO is significantly superior to that of RhB. This work could be expected to make a big step toward the practical application of photocatalysis technology.