Dual Defect-Engineered BiVO4 Nanosheets for Efficient Peroxymonosulfate Activation

TL;DR

Researchers improved BiVO4 nanosheets with defects and nitrogen doping to enhance their ability to break down pollutants in water under visible light.

Contribution

A dual defect-engineered BiVO4 nanosheet design is introduced for efficient PMS activation and visible light-driven photocatalysis.

Findings

BVO-N-OV nanosheets show 7.9 times higher CIP degradation rate than pristine BiVO4.

The system performs well in a broad pH range and with various anions.

N doping and oxygen vacancies synergistically enhance charge transfer and active sites.

Abstract

Defects and heteroatom doping are two refined microstructural factors that significantly affect the performance of photocatalytic materials. Coupling defect and doping engineering is a powerful approach for designing efficient photocatalysts. In this research, we successfully construct dual defect-engineered BiVO4 nanosheets (BVO-N-OV) by introducing N doping and oxygen vacancies through ammonium oxalate-assisted thermal treatment of BiVO4 nanosheets. Due to the combined enhancement of band structure and surface properties from N doping and oxygen vacancies, the obtained BVO-N-OV nanosheets demonstrate improved visible light absorption, effective charge transfer efficiency, and increased active sites. As a result, the constructed BVO-N-OV/PMS system demonstrates significantly enhanced ciprofloxacin (CIP) removal performance under visible light illumination. The highest rate constant for CIP degradation over BVO-N-OV/PMS system is 7.9, 1.9, and 6.6 times greater than pristine BiVO4 (BVO), oxygen vacancy-enriched BiVO4 (BVO-OV), and N-doped BiVO4 (BVO-N), respectively. Even in a broad pH range (3.0–11.0) with various anions, the BVO-N-OV/PMS/Vis system still demonstrates stable and excellent CIP removal performance. This study seeks to provide valuable insights into the interaction between defect and doping engineering in photocatalytic activation of PMS, thereby proposing new strategies for designing effective photocatalyst/PMS systems for wastewater treatment.

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