Three-dimensionally ordered macroporous WO3 supported Ag3PO4 with enhanced photocatalytic activity and durability

Abstract

Ag3PO4 nanoparticles were firstly deposited into the three-dimensionally ordered macroporous WO3 (3DOM-WO3) with different pore sizes. The resulted Ag3PO4/3DOM-WO3 composites were characterized by XRD, SEM, TEM and DR UV–vis. These composite photocatalysts showed extraordinarily excellent efficiencies in the visible light degradation of organic contaminants and water splitting for oxygen evolution, which were mainly due to the synergic effect of Ag3PO4 and 3DOM-WO3 as well as the periodic macroporous structure of 3DOM-WO3. Especially, the catalyst A5W5 with Ag3PO4:WO3 mass ratio of 5:5 exhibited the highest catalytic activity, and complete degradation could be achieved within 4min for phenol and three typical dyes investigated in this work. In addition, the slow photon effect in Ag3PO4/3DOM-WO3 was demonstrated, and the pore size of 3DOM-WO3 was found to have a significant influence on the catalytic performance. The catalyst A5W5(270) showed notably higher photocatalytic activity than A5W5(150) and A5W5 (420), which was mainly attributed to the exact overlap between the stop-band of 3DOM-WO3(270) and the electronic absorption band of Ag3PO4/3DOM-WO3 composite. Moreover, these composite catalysts were very stable and could be recycled ten times without any loss in photocatalytic activity for RhB degradation. More excitingly, remarkably improved activity and durability were also obtained over Ag3PO4/3DOM-WO3 in water splitting for oxygen evolution. According to the XPS and HRTEM characterizations of used catalyst, the enhanced durability was mainly attributed to the effective transfer of photogenerated electrons from Ag3PO4 to 3DOM-WO3.