Ultrafine-Mn2O3@N-doped porous carbon hybrids derived from Mn-MOFs: Dual-reaction centre catalyst with singlet oxygen-dominant oxidation process

Ultrafine-Mn2O3@N-doped porous carbon hybrids [Mn2O3@NC] derived from Mn-MOFs was constructed with 1O2 and O2−• as main Reactive oxygen species (ROS). Cation-π bonds and N-Mn complexation induced the formation of electron-rich Mn centre which provided electron for peroxymonosulfate activation to produce radicals, accompanying with generation of 1O2 via chain reaction. Notably, the porous structure of N-doped carbon shell could not only facilitate free radical recombination for generation of 1O2 but also provide adsorption sites for organics. On the other hand, as electron-poor centre, N-doped carbon shell could improve the electrons transfer from organic intermediate radicals to electron-rich Mn centre via π -π reaction, C-O-Mn and C-N-Mn bonds, which promote the redox of Mn to avoid peroxymonosulfate invalid decomposition. Being attributed to synergistic effects of dual-reaction centres and strong oxidation ability of 1O2, Mn2O3@NC achieved high mineralization of BPA at low-dose peroxymonosulfate (0.033 g/L).