The Efficient Degradation of Bisphenol A with Ozonation Photocatalyzed by TiO₂-rGO Composites under UV Irradiation

TiO₂-rGO composites were synthesized with the liquid phase deposition and calcination method. The as-prepared photocatalysts were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometer (XRD), specific surface and porosity analyzer (BET) and ultraviolet-visible diffuse reflectance spectrophotometer (UV-Vis DRS). The degradation performance of ozonation photocata-lyzed by TiO₂-rGO was investigated using bisphenol A (BPA) as the model pollutant. The reaction mechanism was further explored through the active species trapping experiment. The results showed that anatase TiO₂ nanoparticles about 20 nm in diameter had been successfully anchored on the surface of graphene. The sample obtained when 0.02 g graphite oxide was added in precursor solution exhibited the highest activity and BPA was completely mineralized within 45 min. The catalytic activity of TiO₂-rGO still showed efficient performance after recycling for five consecutive runs. The catalytic activity of TiO₂-rGO was enhanced owing to the improved separation efficiency of photo-generated charges through the introduction of rGO, which benefited the synergistic degradation of photocata-lysis and ozonation. In the reaction process, holes (h⁺) and hydroxyl radical (·OH)were the main active species and ·OH played a dominant role in BPA degradation.