Photocatalytic activation of peracetic acid by metal–free C2N3 for efficient water purification under visible light: High–efficiency bifurcated electron transport

Photocatalytic activation of environmental-friendly and lowcost peracetic acid (PAA) is a "green" strategy for wastewater treatment. Herein, C2N3, an allotrope of g-C3N4, was prepared for the first time via a simple calcination. The C2N3/PAA/Vis system was used to degrade sulfamethoxazole (SMX) and inactivate E. coli. The SMX was completed removed within 70 min, and its degradation rate constant was 10 times that of g-C3N4/PAA/Vis system. The system showed excellent degradation performance under wastewater simulation experiments. Electrochemical and EPR experiments verified that C2N3 acted as an electron donor under visible light, and its electrons were transferred to O2 to produce O2–. PAA acted as another electron acceptor and accepted electrons to generate 1O2 via non-radical pathways. This work reveals that high–efficiency bifurcated electron transport processes enhanced the degradation of contaminants and provides a superior metal–free catalyst/matrix-material for further doping to improve the performance in other applications.