Facile synthesis of a novel WO(3)/Ag(2)MoO(4) particles-on-plate staggered type II heterojunction with improved visible-light photocatalytic activity in removing environmental pollutants

A novel WO(3)/Ag(2)MoO(4) heterojunction has been synthesized through a facile precipitation method with Ag(2)MoO(4) particles firmly deposited on the surface of WO(3) 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 Ag(2)MoO(4) and WO(3). In addition, the heterojunction with 10 wt% Ag(2)MoO(4) displays the best photocatalytic performance, which was about 2 times better than that of pure WO(3) or Ag(2)MoO(4). The TC photodegradation rate reaches up to 91% within 90 min visible light irradiation. Furthermore, the photocatalytic efficiency of the Ag(2)MoO(4)/WO(3) 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 Ag(2)MoO(4) and WO(3), 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.