One-pot solvothermal preparation and enhanced photocatalytic activity of metallic silver and graphene co-doped BiVO4 ternary systems

Abstract

A series of metallic silver and graphene (GR) co-doped monoclinic BiVO4 ternary systems (Ag/GR/BiVO4) are demonstrated by a single-step solvothermal method. The phase and chemical structure, morphology, textural and optical absorption properties of the Ag/GR/BiVO4 ternary systems are well characterized, and then their simulated sunlight and visible-light photocatalytic activity were evaluated by the degradation of a typical dye pollutant, rhodamine B (RhB). For comparison, binary systems of Ag/BiVO4 and GR/BiVO4 as well as solitary BiVO4 are also tested under the same conditions. Meanwhile, the separation and transportation of the photogenerated carriers in the simulated sunlight-irradiating Ag/GR/BiVO4 ternary systems are studied by photoelectrochemistry experiments, and the active species generated during the process of photodegradation are investigated by free radical and hole scavenging experiments. On the basis of the above results, mechanism of photocatalytic degradation of RhB over the Ag/GR/BiVO4 ternary system is revealed. Finally, the reusability of the catalyst was evaluated by five consecutive catalytic runs.