Enhanced photocatalytic activity over the Ag2O–g-C3N4 composite under visible light

Abstract

The Ag₂O–g-C₃N₄ composite was prepared by the coprecipitation method and was well characterized by X-ray diffraction, transmission electron microscopy with energy dispersion X-ray spectroscopy, UV-vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy and surface photovoltage spectroscopy. The photocatalytic activities were evaluated in the degradation of Rhodamine B aqueous solution. The results showed that Ag₂O sized 5–10 nm was highly anchored on the surface of the pure g-C₃N₄ support, causing the Ag₂O–g-C₃N₄ composite to show stronger absorption in the visible light region and higher photocatalytic activities than pure g-C₃N₄ and Ag₂O. The enhanced photocatalytic activities were attributed to combined effects, including highly dispersed smaller Ag₂O particles, stronger visible absorption and higher charge separation efficiency. The possible mechanism for the photocatalytic activity of Ag₂O–g-C₃N₄ was tentatively proposed.