Catalytic ozonation of phenol enhanced by mesoporous MnO2 prepared through nanocasting method with SBA-15 as template

A mesoporous MnO2 (M-MnO2) was prepared by nanocasting method with SBA-15 as the hard template, and was investigated as an ozonation catalyst. The composition and morphology of the as-prepared MnO2 were characterized using X-ray diffraction analysis, transmission electron microscopy and surface area analysis. The ordered nanorods with high surface area (100 m(2)g(-1)) helped the mass transport and the active sites exposed, and thus enhanced the efficiency of catalytic ozonation. The adsorption capacity of M-MnO2 on phenol was about 8 times as high as that of the control MnO2 (C-MnO2) calculated by the Langmuir adsorption model(10.47 mgg(-1)vs 1.20 mgg(-1)). Hydroxyl radical was identified as the main reactive oxygen species, and the hydroxyl radical yield from M-MnO2 is about 2-fold enhanced compared with that from C-MnO2. Benefiting from the high mass transport and abundant active sites exposed, the TOC removal of phenol catalyzed by M-MnO2 (35%) was much better than that by C-MnO2(27%)in 30 minutes.