Research on WO3/BiVO4@FTO Composite as an Efficient Catalyst for Organic Pollutant Degradation, Including its Structure and Photoelectrocatalytic Performance

Abstract

This study aims to develop a highly efficient photoelectrocatalytic material for the degradation of the organic pollutant Rhodamine B (RhB). We successfully fabricated a WO3/BiVO4@FTO composite material using a simple electrodeposition technique. Material characterization revealed that WO3 nanosheets are layered on top of coral-like BiVO4 particles, forming a tightly-bound heterojunction. Optical performance tests showed that the introduction of WO3 significantly enhanced the material’s visible light absorption and slightly reduced its band gap (from 2.52 eV for BiVO4 to 2.50 eV for WO3/BiVO4). More importantly, steady-state/transient fluorescence spectroscopy and EIS tests confirmed that this composite structure effectively promotes the separation of photogenerated electron-hole pairs and reduces charge transfer resistance. Under optimal conditions of 100 mW/cm2 light intensity and a 1.5 V vs. RHE bias potential, the WO3/BiVO4@FTO photoanode achieved over 99% degradation of 10 mg/L Rhodamine B within 120 minutes.Active species trapping experiments indicated that hydroxyl radicals (·OH) and photogenerated holes (h+) are the primary active species responsible for the degradation. Furthermore, the loading of WO3 significantly improved the stability of the composite photoanode compared to the single BiVO4 material. This research provides a new approach for preparing highly efficient and stable photoelectrocatalysts using the electrodeposition method.