Phase conversion during MnC2O4 pyrolysis and the application on high photothermal catalytic degradation of toluene

摘要

Monoclinic Mn5O8 , spinet Mn3O4 , and perovskite Mn2O3 were prepared by thermal decomposition of MnC2O4. The formation of different MnOx species observed by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) measurements showed temperature-dependent phase transformation following the path of MnC2O4 -> Mn5O8 -> Mn3O4 Mn2O3 occurring during the heat treatment process. Among these manganese oxides, the MO-1 (Mn5O8) showed the best light-driven photothermal catalytic performance reaching up to 99% of toluene degradation and 75% of mineralization efficiencies reached within 30 min. Besides, it is found that structural defects decrease with the increase of the calcinated temperature, and the Me-4(+)/Mn3+ active sites and oxygen vacancies play an important role in improving the light-driven photothermal catalytic performance.

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