▎ 摘　　要

Ag3PO4 possesses high photocatalytic activity under visible light, but its application is limited by photogenerated charges recombination, photocorrosion as well as consumption of noble Ag. It is of great interesting to develop new Ag3PO4-based photocatalysts with high charges separation efficiency, good stability and low content of Ag. In this paper, we report a novel Ag3PO4/TiO2/reduced graphene oxide (Ag3PO4/TiO2/rGO) photocatalyst. It exhibits advantages on both the microstructure and the charges separation. The microstructure shows that TiO2 spheres of hundreds of nanometers in size are decorated with dense nano-sized Ag3PO4 to form pinecone-liked particles, which are enwrapped by rGO sheets. This novel structure effectively prevents aggregation of nano-sized Ag3PO4, which not only suppresses the charges recombination in Ag3PO4 but also significantly reduces the content of Ag. Ag3PO4/TiO2/rGO also favors separation of photogenerated charges owing to its two pathways for charges transportation, i.e., the electrons in Ag3PO4 can be transferred to rGO, while the holes in Ag3PO4 can be transferred to TiO2. The dual-pathway for charges separation as well as the pinecone-liked Ag3PO4/TiO2 microstructure ultimately leads to enhanced photocatalytic activity and stability of Ag3PO4/TiO2/rGO. The photocatalytic performance varies with different contents of Ag3PO4 in the composites, because low content of Ag3PO4 induces weak light absorption while excess Ag3PO4 results in serious charges recombination due to the aggregation of Ag3PO4 nanoparticles. In this work, Ag3PO4/TiO2/rGO with weight ratio of Ag3PO4 against TiO2/rGO equals to 0.6 exhibits the highest photocatalytic activity. The percentage of Ag in this composite is around 29 wt%, much lower than 77 wt% in pure Ag3PO4. (C) 2015 Elsevier B.V. All rights reserved.