Fabrication of TiO2/Ag/Ag2O Nanoparticles to Enhance the Photocatalytic Activity of Degussa P25 Titania
A simple chemical reduction approach was used to synthesize Ag nanoparticles (NPs) over a reputed photocatalyst, Degussa P25 (TiO2). Silver doping extended the P25 absorption wavelength from the ultraviolet to the visible region. The synthesized silver NPs (Ag NPs) were of spherical shape and had an average size of ~4.6 nm. In the next stage, Ag NPs were partially oxidized by treatment with hydrogen peroxide. The resulting P25/Ag/Ag2O nanocomposites were characterized by X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray analysis, Brunauer–Emmett–Teller analysis, and UV-visible spectroscopy. The photocatalytic activities of the P25, P25/Ag, and P25/Ag/Ag2O catalysts were investigated for the degradation of non-biodegradable dyes, methylene blue and rhodamine 6G. The P25/Ag/Ag2O nanocomposite exhibited better photodegradation activity than P25, as well as the commonly used Ag3PO4, under visible light irradiation.