The synthesis of Ag3PO4/g-C3N4 nanocomposites and the application in the photocatalytic degradation of bisphenol A under visible light irradiation

Highlights: • The novel material Ag₃PO₄/g-C₃N₄ were prepared and used in bisphenol A degradation. • The 92.8% bisphenol A can be degraded by Ag₃PO₄/g-C₃N₄ with 25% Ag₃PO₄ mass ratio. • The photodegradation kinetics and possible photocatalytic mechanism were discussed. • Active specie ·O₂⁻ was found to play a key role during the photocatalytic reaction. The high-efficient photocatalytic material Ag₃PO₄/g-C₃N₄ was synthesized through calcination and precipitation methods. The physico-chemical properties of the material were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy (DRS) photoluminescence spectra (PL) and Brunauer-Emmett-Teller (BET) surface area test. The morphology analysis indicated that Ag₃PO₄ particles were heterogeneously dispersed on the surface of layered g-C₃N₄. The Ag₃PO₄/g-C₃N₄ nanocomposites were applied in the photodegradation of bisphenol A under the visible light irradiation. The effects of the material proportion, the initial concentration of BPA, and the salinity on the degradation were discussed. The results showed that 92.8% bisphenol A (10 mg/L) can be photodegraded under 3 h irradiation by Ag₃PO₄/g-C₃N₄ with 25% Ag₃PO₄ mass ratio. The photodegradation kinetics and possible photocatalytic mechanism were discussed. The active specie ·O₂⁻ was found to play a key role during the photocatalytic reaction. The reaction mechanism was described based on valence band, conduction band energy levels and reduction potentials of oxygen and hydroxyl radicals.