Efficient photocatalytic ozonation of azithromycin by three-dimensional g-C3N4 nanosheet loaded magnetic Fe-MCM-48 under simulated solar light

Magnetic g-C3N4/Fe-MCM-48 with unique 3-D structure was facilely prepared. MCM-48 framework was uniformly doped with Fe atoms, and then wrapped by g-C3N4 nanosheet to obtain ordered g-C3N4/Fe-MCM-48, which triggered an excellent synergistic effect and showed perfect activity and stability in photocatalytic ozonation of azithromycin (AZY). The removal rate of AZY by simulated solar light/g-C3N4/Fe-MCM-48/O3 was close to 100% within 11 min, and the kinetic constant of catalysis with g-C3N4/Fe-MCM-48 was 9.2 times as much as that of g-C3N4 in coupling system. The synergy index was 8.6 for simulated solar light/g-C3N4/Fe-MCM-48/O3. The influence of Fe contents and initial pH in the removal of AZY was investigated. The recycling of catalyst was significantly enhanced by excellent stability and magnetic property. Besides, the quenching experiments demonstrated that both hydroxyl radical and holes contributed to AZY removal, the possible removal pathway of photocatalytic ozonation of AZY had also been comprehensively studied.