Insight into the enhanced photocatalytic activity mechanism of the Ag3VO4/CoWO4 p–n heterostructure under visible light

Abstract

A novel Ag₃VO₄/CoWO₄ (AgCoO) p–n heterostructure was designed and prepared by an in situ growth method. The physicochemical properties of the as-prepared materials were characterized by multiple techniques, and the photocatalytic performances in Cr(VI) reduction and TC degradation were also evaluated under visible-light irradiation. The optimal AgCoO_0.20 exhibited excellent Cr(VI) reduction activity (98.5% removal rate) and TC degradation activity (71.4% removal rate). The enhanced Cr(VI) reduction and TC degradation performances were attributed to fast transportation and efficient separation of the charge carriers due to the synergistic effect of the sufficient interfacial contact and the interaction between CoWO₄ and Ag₃VO₄ induced by the formation of the p–n heterostructure. Ultimately, the possible enhanced photocatalytic mechanism over the Ag₃VO₄/CoWO₄ p–n heterostructure composite was also proposed.