Preparation of Oxygen-Doping Nongraphitic Carbon Nitride via Efficiency Exfoliation for the Application of Photocatalytic Degradation.

E-OLCN photocatalyst was synthesized by oxygen doping of low molecular weight carbon nitride (LCN) with ethanol solvent stripping. The enhanced light absorption, fast electron transport rate, and photogenerated carrier separation efficiency of E-OLCN leads to the excellent photocatalytic degradation performance compared with the original materials. The synergistic effect of oxygen doping and ethanol solvent stripping plays a significant role for the modulation of electronic and structural properties of the prepared catalysts. Methyl orange (MO) and rhodamine B (RhB) are chosen as typical pollutants for the application of photocatalytic degradation. The E-OLCN sample exhibits outstanding photocatalytic degradation performance, where the rate constant (1 × 10 min) of E-OLCN (1.68) is 2.9 times than that of O-LCN (0.58) and 8.8 times than that of pristine LCN (0.19) for MO. Moreover, modulated E-OLCN shows good stability after cycling experiments and the activity still achieved 90%. The detailed mechanism for MO degradation was proposed with the technical support of liquid chromatography-mass spectrometry (LC-MS) and electron spin resonance (EPR). The superoxide radical (·O) is the main active species and the MO molecule could be decomposition completely.