Facile synthesis of a novel WO/AgMoO particles-on-plate staggered type II heterojunction with improved visible-light photocatalytic activity in removing environmental pollutants.

A novel WO/AgMoO heterojunction has been synthesized through a facile precipitation method with AgMoO particles firmly deposited on the surface of WO nanoplates, forming "particles-on-plate" type II heterojunction structures. This heterojunction exhibited improved photocatalytic activities for the degradation of rhodamine B (RhB), 4 chlorophenol (4-CP) and tetracycline hydrochloride (TC) under visible-light irradiation compared to pure AgMoO and WO. In addition, the heterojunction with 10 wt% AgMoO displays the best photocatalytic performance, which was about 2 times better than that of pure WO or AgMoO. The TC photodegradation rate reaches up to 91% within 90 min visible light irradiation. Furthermore, the photocatalytic efficiency of the AgMoO/WO heterojunction is 1.3 times higher than that of the mixture of the two individual photocatalysts. This remarkable enhanced photocatalytic performance results from the staggered bandgap between AgMoO and WO, which can suppress the recombination of electron-hole pairs efficiently. Moreover, based on the radical trapping experiment, the superoxide radical anions (·OH) and photogenerated holes (h) are the crucial active oxidizing species.