Preparation and characterization of BiVO4 film electrode and investigation of its photoelectrocatalytic (PEC) ability under visible light

BiVO4 film coated on F-doped SnO2 (FTO) glass was successfully fabricated by modified metalorganic decomposition (MOD) technique. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) images showed that the film was composed of grains with 200–300 nm in size and the grains were composed of particles, which were about 10 nm in size. Diffused reflectance spectroscopy (DRS) revealed that the absorption performance of the BiVO4 film was intense in visible light region and the band gap was 2.43 eV. The analysis of X-ray diffractometry (XRD) and Raman spectra identified to the monoclinic type BiVO4. Photoelectrochemical measurements indicated the photocurrent densities of BiVO4 films had an elevation with the increase of film thickness from 0.23 to 1.04 μm due to enhanced amount of absorption of the incident photons. The removal rate of phenol in photoelectrocatalytic (PEC) process by the BiVO4 film electrode under visible light (>400 nm) was 27.1 times that in photocatalytic (PC) process. The prominent enhancement was induced by the promoted separation of photogenerated electron–hole pairs. Furthermore, the BiVO4 film electrode coated on FTO glass showed good stability in the PEC process.