A novel Ag2O/g-C3N4 p-n heterojunction photocatalysts with enhanced visible and near-infrared light activity

A series of p-n junction Ag2O/g-C3N4 photocatalysts with different Ag2O contents were successfully prepared though a facile chemical precipitation method at room temperature. The as-synthesized samples were characterized in detail by XRD, EDS, XPS, SEM and DRS. The experimental results demonstrated that Ag2O nanoparticles were well distributed on the surface of g-C3N4 and the heterostructure of Ag2O/g-C3N4 was constructed. As-synthesized Ag2O/g-C3N4 heterojunction photocatalysts exhibited an excellent wide-spectrum response ranging from ultraviolet (UV) to near-infrared (NIR), indicating its potential for effective utilization of solar light energy. The as-prepared Ag2O/g-C3N4 shows excellent photocatalytic properties for the degradation of Rhodamine B (RhB), phenol, imidacloprid, methylene blue (MB) and methyl orange (MO) under visible and NIR light irradiation. The degradation rate constants of Ag2O/g-C3N4 (8:1) for RhB were 0.05188 and 0.01368 min−1 under visible and NIR irradiation, which are about 26 and 343 times higher than that of pure g-C3N4, respectively, and are even better than that of Ag2O under the same conditions. The enhanced photochemical activities are attributed to the formation of the heterostructure between Ag2O and g-C3N4, and efficient charge separation efficiency. Finally, a possible photocatalytic mechanism was proposed for this photocatalyst.