Facile one-pot synthesis of carbon self-doped graphitic carbon nitride loaded with ultra-low ceric dioxide for high-efficiency environmental photocatalysis: Organic pollutants degradation and hexavalent chromium reduction

In the present study, an innovative carbon self-doped g-C3N4 (CCN) loaded with ultra-low CeO2 (0.067–0.74 wt%) composite photocatalyst is successfully synthesized via a facile one-pot hydrothermal and calcination method. The CeO2/CCN exhibits superior photocatalytic performance for tetracycline degradation (78.9% within 60 min), H2O2 production (151.92 μmol L-1 within 60 min), and Cr(VI) reduction (99.5% within 40 min), which much higher than that of g-C3N4, CCN, CeO2, and CeO2/g-C3N4. The enhanced photocatalytic performance is originated from the fact that the doping of C can efficaciously broaden the utilization range of solar light and improve the reduction ability of photogenerated electrons. Meanwhile, the ultra-low loading of CeO2 can effectually promote the migration of photogenerated electrons and enhance the specific surface area. Besides, the experiments of pH effect and cycle ability indicate that CeO2/CCN has excellent durability and stability. Finally, the photocatalytic mechanism of CeO2/CCN is systematically discussed. This work proves that combining element doping and semiconductor coupling is a promising strategy to design high-efficiency g-C3N4-based photocatalysts.