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

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.