Novel amoxicillin degradation via photocatalysis of WO3/AgI heterojunction decorated on rGO

Abstract

In the study, rGO was used as an electron mediator to establish WO3@rGO@AgI (WrGA) ternary heterojunction to apply for degradation of Amoxil upon excitation of visible light. Various characterization methods and technologies, such as XRD, SEM, TEM, UV–Vis and PL, and trapping experiments of active species were applied to determine charge separation as well as degradation mechanism. The achieved data showed that both WO3 and AgI in the synthesized WrGA had suitable band gap energies to absorb provided visible light for e− jumping from valence band (VB) to conduction band (CB) leaving h+ at the VB. Then, the rGO effectively acted as e− mediator to promote Z scheme mechanism for its migration from the WO3 CB to the AgI VB to prevent charge recombination in WO3 as well as AgI. The charge separation via Z scheme mechanism also maintained significant charges (e− at AgI CB and h+ at WO3 VB) with high redox potentials for photocatalysis. Therefore, the Amoxil degradation efficiency of the WrGA was 24% higher than that of the WA (without rGO). Finally, the recycling tests showed novel stability and recycling potential of the synthesized WrGA opening new era for its application in practical system for degradation of organic pollutants.