Depositing Ag3PO4 on WO3 hollow microspheres at room temperature for rapid photocatalytic degradation of Rhodamine B

A series of WO3 hollow microspheres decorated with Ag3PO4 nanoparticles (APW) composites with Ag3PO4:WO3 mass percentage of 20% (20APW), 30%(30APW), 40%(40APW) and 50% (APW) were successfully synthesized, characterized and tested for the degradation of the Rhodamine B(RhB) under 300 ​W xenon lamp radiation. The photocatalytic results showed that the photocatalytic degradation performances of WO3 hollow microspheres decorated with Ag3PO4 nanoparticles on RhB were significantly enhanced, which were much higher than that of individual Ag3PO4 and WO3. Especially for 40APW, RhB can be completely degraded within 10 ​min. The order of degradation efficiency is 20APW<50APW< 30APW<40APW. The rate constant of 40APW (0.3902 min−1) is about 81.3 times that of WO3 (0.0048 min−1). The diffuse reflection, photoluminescence and electrochemical impedance tests showed that the formation of Ag3PO4/WO3 composite structure broadened the light absorption range, reduced the recombination rate of photogenerated electrons and holes, and decreased the resistance to charge transfer, which are beneficial to the improvement of photocatalytic performance. The capture agent experiments were carried out with 40APW, which specified the primary role of h+ and ⋅O2− in the degradation of RhB. The formation of heterojunction between Ag3PO4 and WO3 that effectively separates photogenerated electrons and holes are contributed to the enhancement of photocatalytic properties of APW composites.