Geometric architecture design of ternary composites based on dispersive WO3 nanowires for enhanced visible-light-driven activity of refractory pollutant degradation

Abstract

Geometric architecture of composite photocatalytic system creates a favorable chance for enhanced photocatalytic activity, which is a challenging and rewarding direction in this area. Here, a novel and highly efficient three-components composite consisting of dispersive WO3 nanowires, g-C3N4 nanosheets and RGO as solid electron mediator was successfully designed, synthesized and characterized. The WO3/RGO/g-C3N4 composite exhibited markedly enhanced activity for the photocatalytic degradation of aflatoxin B1 under visible-light irradiation compared with single and binary catalysts. It was found that the synergistic effects coexisted in this ternary composites that depended on the geometric architecture and interface combination of components. The Z-scheme system formed when RGO was as an interlayer between WO3 and g-C3N4, while the mechanism was the heterojunction-type in absence of RGO. It was found that the O2−, h+ and OH were main active radicals during photodegradation of AFB1 over ternary composites, which was proved by the radical trapping tests and ESR detection. Finally, a probable enhanced photocatalytic degradation mechanism of ternary composites and the degradation products were also proposed. This work may not only provide beneficial information to design and synthesis of effective composites system, but also present a new way to remove the refractory natural pollutant.