CaMnO3 perovskite nanocrystals for efficient peroxydisulfate activation

Perovskite oxides ABO 3 with unique structure showed promising performance on persulfates activation. Previous research works mainly focused on Co-based or rare earth metal (La, Sr)-based perovskite oxides for peroxymonosulfate (PMS) activation. Here, we firstly studied perovskite CaMnO 3 metal oxide composed with the low cost and eco-friendly Ca and Mn elements for PDS activation. Perovskite CaMnO 3 metal oxide achieve the superior catalytic activity for reactive oxygen species generation than the regular Mn oxides (β-MnO 2 and Mn 2 O 3 ) and other types Ca x Mn y O z (spinel-type CaMn 2 O 4 and Ca 2 MnO 4 ) solid solution due to the tolerance of Mn multivalence and defects in the perovskite structure and the excellent Mn 3+ /Mn 4+ redox capacity in CaMnO 3 . The CaMnO 3 /PDS system could be applied at a wide pH range from 4 to 12, and exhibited better performance in basic conditions. Different active species including SO 4 − , OH reactive radicals and singlet oxygen 1 O 2 were found and responsible for effective pollutants degradation. Our study shows eco-friendly perovskites possess great potential in the refractory organic pollutants removal by catalytic activation of PDS.