Photoelectrocatalytic oxidation of phenol for water treatment using a BiVO4 thin-film photoanode

The removal of organics by photoelectrocatalytic oxidation offers a viable option to remove the contaminants at low concentrations. In this paper, we propose a BiVO 4 thin films synthesized via spray pyrolysis for photoelectrocatalyic oxidation of phenol with solar light. We compare the properties of BiVO 4 with those of the commonly used photocatalyst TiO 2 . In addition, BiVO 4 films with W gradient doping were fabricated and tested for improving the photocatalytic performance of BiVO 4 . X-ray diffraction, atomic force microscopy, incident photon to current efficiency and spectrophotometry have been conducted for BiVO 4 films of different thicknesses, as well as for TiO 2 . The electrochemical impedance spectroscopy and dark conductivity measurements were conducted. Phenol removal has been measured for both the TiO 2 and BiVO 4 samples. The best performance was found to be for a 300 nm undoped BiVO 4 film, being able to reduce the phenol concentration up to 30.0% of the initial concentration in four hours.