Photocatalytic degradation of organic pollutants by Ag<inf>2</inf>O/AgSiO<inf>x</inf>

Abstract

Silver silicate (AgSiOx) is a visible-driven photocatalyst. However, the efficiency of single component photocatalysts can be improved by coupling with other compounds. In this work, AgSiOx was coupled with different amounts of Ag2O using a co-precipitation method. Ratios of Ag2O:AgSiOx were controlled by varying the concentrations of Na2SiO3.9H2O and NaOH. All prepared products were characterized by X-ray diffractometry, transmission electron microscopy, X-ray photoelectron spectroscopy, surface analysis, and UV–vis diffuse reflectance spectroscopy. Under visible light irradiation, the Ag2O/AgSiOx composite could degrade rhodamine B, reactive orange, and bisphenol A solutions. The Ag2O/AgSiOx exhibited greater photocatalytic activity than AgSiOx and Ag2O because this composite improved visible light absorption and inhibited charge recombination. The Ag2O/AgSiOx prepared from 0.012 mol NaOH exhibited the highest photocatalytic activity. Photocatalytic degradation of all pollutant models to low mass species was studied by electrospray ionization mass spectrometry and the cytotoxicity of pollutant model solutions before and after photocatalytic processes was evaluated on L929 mouse fibroblast cells using the MTT assay.