Construction of 2D/2D Bi₄O₅Br₂/Bi₂WO₆ Z-scheme heterojunction for highly efficient photodegradation of ciprofloxacin under visible light

Enhancing the heterointerface contact determined by the dimensionality of each component is essential for the rapid migration of photogenerated charge carriers. Herein, the 2D/2D Bi₄O₅Br₂/Bi₂WO₆ Z-scheme heterojunction was successfully synthesized through a simple chemical co-precipitation followed by a hydrothermal process. Remarkably, the optimized Bi₄O₅Br₂/Bi₂WO₆ heterojunction achieved superior photocatalytic efficiency of 91.0% and ascendant stability for the degradation of ciprofloxacin (CIP) under visible light illumination. More importantly, degradation pathway and photocatalytic mechanism analysis revealed that the reinforced photodegradation efficiency can be ascribed to the intimate heterointerface between 2D Bi₄O₅Br₂ and 2D Bi₂WO₆, which facilitated the fast migration and separation of photoinduced carriers, thus enhancing the photocatalytic activity. Furthermore, the effect of pH, CIP concentration, inorganic cations and anions, and different contaminants were systematically investigated to explore the potential of practical applications. This work gives rational insight into the developing 2D/2D Z-scheme heterojunction for environmental remediation.