Hydrothermal preparation of B–TiO2-graphene oxide ternary nanocomposite, characterization and photocatalytic degradation of bisphenol A under simulated solar irradiation

Boron-doped TiO₂ decorated on graphene oxide photocatalysts (denoted as GO@B–TiO₂) were prepared for the effective photocatalytic treatment of bisphenol A (BPA) from water under simulated solar light. To prepare GO@B–TiO₂ nanocomposites, B–TiO₂ was initially synthesized via a sol-gel procedure and subsequently decorated on graphene oxide at 70 ^°C, by a facile hydrothermal method. Characterization results show that B–TiO₂ particles are anchored on the surface of graphene oxide successfully. Their photocatalytic efficiency could also be adjusted by changing the ratios between B–TiO₂ and GO. The optimum GO loading is 2 wt%, at which GO@B–TiO₂ nanocomposite photocatalyst could achieve the best BPA degradation percentage of 47.66% compared with B–TiO₂ materials (18.78%) after 240 min of solar irradiation. The dominant reactive oxygen species (ROS) formed during the photocatalytic abatement of BPA were determined to be O₂^.- and ^.OH. The presence of carbonate and chloride induced moderate inhibitory effect on GO@B–TiO₂ (2 wt% GO), while bicarbonate and nitrate displayed only minor effect towards photocatalytic degradation of BPA. Based on these results, the as-prepared nanocomposites may be used as efficient and promising photocatalysts in secondary treatments to degrade recalcitrant contaminants in water exploiting the visible-light region of the full solar spectrum.