N, P-dual doped carbonaceous catalysts derived from bifunctional-salt activation for effective electro-Fenton degradation on waterborne organic pollutions

Abstract To achieve the two-electron governed oxygen reduction reaction (ORR) is the major challenge for carbonaceous catalyst in the electro-Fenton (EF) degradation on the exhaustive stubborn pollutants from industrial wastewater. Herein, a bifunctional salts strategy utilizing EDTA-2K and NaH2PO2.H2O as heteroatom dopants and porogens is proposed to regulate the doping amounts of N, P heteroatoms as well as the content of active species (pyrrolic-N and P-C bonding motifs) to enhance 2e--ORR selectivity for EF degradation. It is found that the generated gaseous substances could serve as soft template to create micro-/meso-pores for the accommodation of highly oxidizing .OH radicals. In addition, thanks to the high N, P doping amounts (both are 2.9 at. %, respectively), large specific surface area (1388 m2 g-1) and appropriate pore sizes (1.5/3.8 nm), the optimized carbonaceous catalyst enables high EF degradation efficiencies up to 98.4 % (60 min) and 97.1 % (150 min), respectively for methyl yellow and mixed dyes with good stability and reusability. The current work paved a new concept to engineer the carbonaceous catalysts for the promoted catalytic activity and selectivity in the electro-degradation of organic pollution.