Synthesis, characterization and photocatalytic activity of graphene quantum dots-Ag solar driven photocatalyst

Recently, photo degrading organic waste material is a hot topic. Many photocatalysts based on semiconductor oxide have been reported. Although they have excellent catalytic activity under ultraviolet (UV) irradiation, it is difficult to practical application because of the limited ratio of UV light in whole solar irradiation. In this work, we prepared solar driven photocatalyst based on graphene quantum dots (GQDs) and silver nanoparticles (Ag NPs) by simple photo-reduction reaction. In the synthesized process, GQDs were served as reducing agent for Ag cations and capping agent for the in situ formation of Ag NPs with small size. Although the used concentration of Ag cations was very low (just 0.54 mg/ml), GQDs–Ag photocatalyst exhibited a high efficiency for photo degradation Rhodamine B under sunlight. It could be ascribed to the synthetic role of Ag NPs and GQDs, and further the detailed photocatalytic mechanism was analyzed in this paper. Because this kind of photocatalyst made from water solution and can be driven by sunlight, it is a promising photocatalyst for industrial applications in the environmental remediation field.