Highly efficient AgVO3/WO3 photocatalyst n-n heterojunction toward visible-light induced degradation antibiotic

Abstract

In the present work, WO₃ NPs were fabricated using a facile hydrothermal method assisted by polyvinylpyrrolidone (PVP) for the first time, and AgVO₃ with different weight percentages (3%, 6%, 9% and 12%) was uniformly distributed on the surface of mesoporous WO₃ by impregnation - calcination processes to construct n-n heterojunction AgVO₃/WO₃ nanocomposites. The obtained AgVO₃/WO₃ nanocomposites were utilized for the effective Ciprofloxacin (CIP) degradation during visible illumination. The XRD and TEM investigations verified the formation of AgVO₃ and WO₃ in a monoclinic crystal structure with a particle size of 40 nm. XPS and TEM measurements evidenced the existence of Ag^o and Ag⁺ in the heterostructure AgVO₃/WO₃ system. 9%AgVO₃/WO₃ nanocomposite exhibited larger photocatalytic performance, i.e., 100% with 120 min of illumination, than the other nanocomposite photocatalysts. The apparent rate constant of 9% AgVO₃/WO₃ nanocomposite (0.0162 min⁻¹) was enhanced 18 times greater than the WO₃ NPs (0.0009 min⁻¹). The efficient photocatalytic performance could correlate with the close contact between AgVO₃ and WO₃ NPs, which enhanced the visible light absorption and efficacious separation of the carriers during degradation reactions. The AgVO₃/WO₃ nanocomposite obeyed the S-scheme mechanism for charge transfer to achieve promising redox abilities in both AgVO₃ and WO₃. The optimized 9% AgVO₃/WO₃ photocatalyst showed high reusability and photostability for five consecutive runs without loss its efficiency. This study provides a new mechanism for addressing highly effective nanocomposites with excellent photocatalytic ability that exhibit practical applications in the environmental remediation of antibiotics.