Porous Oxygen-Doped g-C3N4 with the Different Precursors for Excellent Photocatalytic Activities under Visible Light

Antibiotic contamination has received widespread attention globally. In this work, the oxygen-doped porous graphite carbonitride (g-C3N4) was prepared with urea and ammonium oxalate (CNUC) or urea and glycine (CNUG) as precursors by thermal polymerization. Using bisphenol A (BPA) as a probe and CNUC or CNUG as photocatalysts, the removal performance test was carried out. Meanwhile, all prepared photocatalysts were characterized by XRD, FT-IR, SEM, TEM, XPS, UV-Vis DRS, PL and EIS. Under visible light irradiation, both CNUC and CNUG exhibited about seven and five times greater photocatalytic activity than that of pure g-C3N4, respectively. The radical capture experiments verified that superoxide radicals (•O2-) and holes (h+) were the main active species in the photocatalytic degradation of BPA by CNUC, and the possible photocatalytic mechanism of CNUC was proposed. In addition, all these results indicate that CNUC catalyst can effectually inhibit the photocorrosion and keep superior stability. The proposed technique provides a prospective approach to develop nonmetal-modified photocatalysts for future applications.