Boosting 2e− oxygen reduction reaction in garland carbon nitride with carbon defects for high-efficient photocatalysis-self-Fenton degradation of 2,4-dichlorophenol

Photocatalytic two-electron oxygen reduction reaction (2e-ORR) has been regarded as a promising strategy to solve the disadvantage of Fenton technology (constant addition of H2O2). Herein, a photocatalysis-self-Fenton system was constructed on garland g-C3N4 with carbon defects (GCN-PSFs) for pollutants degradation. Carbon defects in the obtained GCN not only accelerate charge separation but also improve 2e- ORR. As expected, the apparent rate constant for 2,4-DCP degradation by GCN-PSFs enhances to 0.070 min−1, which is 5.4, 3.3 and 2.6 times as that of BCN, BCN-PSFs and GCN. The capture experiments and electron spin resonance indicate that the high activity is attributed to abundant ∙OH radicals, which are formed from the in-situ produced H2O2. Density functional theory (DFT) calculation confirms that the carbon defects in GCN is favorable for photocatalytic 2e- ORR to H2O2. This work provides a new insight for high-efficient degradation of organic pollutants by PSFs.