The Photocatalytic Mineralization of Phenolic Wastewater Via Self-Generation and -Activation of H2O2 Technology

Achieving efficient photocatalytic degradation and mineralization of phenolic pollutants under mild conditions is the key to solving the environmental crisis. Herein, a novel self-generation and -activation of H2O2 technology is achieved on graphitic carbon nitride (GCN)/anthraquinone-based covalent organic frameworks (TD-COF) het-erojunction photocatalysts (CNTD-X). Some of the photogenerated electrons (e-) that migrate directionally to the surface of TD-COF could generate H2O2 via oxygen reduction reaction (ORR) route, while the e- gathered around anthraquinone can reduce it to stable semi-quinone radicals, which can further release hydroxyl radical (& sdot;OH) through electron transfer with H2O2. The photogenerated holes (h(+)) gathered on the surface of GCN would provide important raw materials for ORR reaction through oxidation of water, and participate in the minerali-zation process of pollutants. With the ring opening of & sdot;OH and the oxidation of h(+), this heterojunction system can achieve efficient phenolic pollutants removal. The optimal sample of CNTD-0.02 possesses an incredible phenol removal (99.4%) within 12 min under visible light irradiation (lambda >420 nm), and total organic carbon (TOC) analysis shows 81% phenol is converted into CO2 and H2O. The photo-degradation rate of CNTD-0.02 is about 204.2 and 26.8 times that of GCN and TD-COF, respectively. This novel photocatalytic strategy over CNTD-X could also be applied in other phenolic pollutants removal, and our work paves a new way for environmental remediation in clean and efficient technology.