2022-04-01, Lyu, Zhiping, Xu, Menglu, Wang, Jinnan, Li, Aimin, Corvini, Philippe

Hierarchical nano-vesicles with bimetal-encapsulated (FeCu1.5O3@NV) was designed for peroxymonosulfate (PMS) activation with the 1O2-dominated oxidation process. Different from previous core–shell metal-loaded catalysts, FeCu1.5O3 was encapsulated in hollow zeolite spheres, and these zeolite sphere units assembled to construct hierarchical nano-vesicles. Owning to mesoporous shell and abundant interior cavity, FeCu1.5O3@NV could enrich reactants in cavity for enhancing the contact with active sites. The flexible surface of bimetal oxides strengthened the affinity with surface adsorbates and substrates, accelerating the electron transfer between reactants. DFT calculation indicated that FeCu1.5O3@NV possessed strong binding affinity for BPA and PMS, facilitating PMS activation and BPA degradation inside of hollow sphere units. Being attributed to the synergistic effect of bimetal redox couples and hierarchical nano-vesicle structure, large amounts of 1O2 could be generated through two pathways for BPA degradation. The first pathway is the reaction between bimetal redox couples and PMS, and the second is the chain reaction of O2•−. Due to bimetal oxides uniformly encapsulated in hierarchical nano-vesicles, FeCu1.5O3@NV possessed high catalytic stability with negligible metal leaching. Even after 5 cycles, BPA removal could still remain 100%.

2022, Xie, Zhiqun, Lyu, Zhiping, Wang, Jinnan, Li, Aimin, Corvini, Philippe

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).