Visible-light-driven Activation of Persulfate by RGO/g-C3N4 Composites for Degradation of BPA in Wastewater

Persistent organic pollutants can be effectively removed by photocatalytic oxidation, which reveals potential application prospects in the field of wastewater purification. Binary reduced graphene oxide and graphitic carbon nitride (RGO/g-C3N4) visible-light photocatalyst was successfully fabricated by the freeze drying assisted thermal polymerization method with urea and dicyandiamide as raw materials, respectively. The morphologies, structures and optical properties were characterized by various techniques. It was found that g-C3N4 and RGO nanostructures formed an intimate contact across the heterojunction interface. The photodegradation performances of catalysts were evaluated by removing bisphenol A (BPA) with the activation of persulfate (PS). The results indicated that the photocatalytic activities of photocatalysts were enhanced with the addition of PS as an oxidant and electron acceptor under visible light irradiation (lambda>420 nm). Moreover, BPA was almost completely removed by RGO/g-C3N4 prepared with urea as raw material in 40 min. After five recovery tests, the removal efficiency of BPA for the catalyst was up to 80% within 40 min under visible light irradiation, which exhibited superior stability.