Facile Synthesis of a Bi₂WO₆/BiO_2−x Heterojunction for Efficient Photocatalytic Degradation of Ciprofloxacin under Visible Light Irradiation

Abstract

In this work, a Z-scheme Bi2WO6/BiO2−x heterojunction was successfully prepared using a self-assembly strategy. Various characterization techniques demonstrated that the formation of the heterojunction not only accelerated the separation of photoinduced carriers but also weakened the recombination rate of photogenerated electron–hole pairs-. The Bi2WO6/BiO2−x composites had a wider absorption edge than Bi2WO6 in the range of 200–800 nm, which improved the photocatalytic performance of ciprofloxacin (CIP) degradation under xenon lamps. As a result, the Z-scheme heterojunction Bi2WO6/BiO2−x composite exhibited excellent photocatalytic activity. Catalyzed by the optimal 20% Bi2WO6/BiO2−x (0.5 g/L), the removal rate of CIP (10.0 mg/L) was 91.8% within 2 h irradiated by visible light, which was 2.37 times that of the BiO2−x catalyst. This work will provide a fresh perspective on the construction of visible-driven Z-scheme photocatalysts for wastewater treatment.

Keywords

• photocatalysis
• ciprofloxacin
• Bi₂WO₆
• BiO_2−x
• Z-scheme heterostructure