LAUSR

The heterojunction P25/g-C3N4 was successfully prepared by one-step method, and the phase structures, optical properties, morphology, charge separation, and transfer efficiency of obtained samples were characterized by X-ray diffraction, UV-visible, Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, photoluminescence spectroscopy, respectively. The photocatalytic ozonation activity of samples was systematically evaluated by degrading 2.4-D under visible light irradiation. The results showed that P25/g-C3N4 heterojunction has remarkable catalytic activity and 3 wt.%-P25/g-C3N4 shows the best photocatalytic ozonation activity of 2,4-D (90.2%, 30 min, 30 mL/min O3). The synergy factor between photocatalysis and ozonation is 9.34, indicating that increased synergy rate between photocatalysis and ozonation during the reaction. The cycling experiments show that catalyst 3 wt.%-P25/g-C3N4 has good stability and the trapping experiments indicate the main active substance in the reaction are O3 and •OH.