Enhanced photocatalytic degradation of ciprofloxacin over Bi2MoO6/g-C3N4/BiFeO3 heterojunction photocatalyst under visible light irradiation

A novel ternary Bi2MoO6/g-C3N4/BiFeO3 heterojunction composite catalyst was successfully prepared using a facile solvothermal method for the efficient degradation of ciprofloxacin (CIP). The characterization results demonstrate that the heterojunctions among g-C3N4, BiFeO3, and Bi2MoO6 are formed. The heterojunctions can narrow the bandgap and improve the separation and migration of photogenerated electron-hole pairs. The catalyst possesses the optimum photocatalytic activity toward CIP degradation under visible light irradiation. The free radical trapping experiments manifest that h+, ·O2−, and ·OH all contribute to the degradation of CIP. Among them, ·OH plays the main role in photocatalytic degradation. The possible photocatalytic mechanism of the Bi2MoO6/g-C3N4/BiFeO3 catalyst to degrade CIP is proposed. Moreover, the catalyst reveals excellent photostability and reusability after three photocatalytic cycles under the same conditions. This study not only confirms the feasibility of the catalyst for efficient degradation of CIP but also provides a facile method to synthesize the novel Bi2MoO6/g-C3N4/BiFeO3 heterojunction composite catalyst with enhanced photocatalytic activity.