Degradation of bisphenol A in aqueous solution by H₂O₂-assisted photoelectrocatalytic oxidation

Abstract

A series of titanium dioxide (TiO₂/Ti) film electrodes were prepared from titanium (Ti) metal mesh by an improved anodic oxidation process and were further modified by photochemically depositing gold (Au) on the TiO₂ film surface as Au–TiO₂/Ti film electrodes. The morphological characteristics, crystal structure and photoelectroreactivity of both the TiO₂/Ti and Au–TiO₂/Ti electrodes were studied. The experiments confirmed that the gold modification of TiO₂film could enhance the efficiency of e⁻/h⁺ separation on the TiO₂ conduction band and resulted in the higher photocatalytic (PC) and photoelectrocatalytic (PEC) activity under UV or visible illumination. To further enhance the TiO₂PEC reaction, a reticulated vitreous carbon (RVC) electrode was applied in the same reaction system as the cathode to electrically generate H₂O₂ in the aqueous solution. The experiments demonstrated that such a H₂O₂-assisted TiO₂PEC reaction system could achieve a much better performance of BPA degradation in aqueous solution due to an interactive effect among TiO₂, Au, and H₂O₂. It may have good potential for application in water and wastewater treatment in the future.