Interfacial-engineered MOFs-POPs derived Co@N-doped carbon catalyst in boosting peroxymonosulfate activation and pollutant degradation: Roles of microstructure and exposed facets

Abstract

Developing potent and durable heterogeneous catalysts is pivotal for advancing the implementation of the advanced oxidation processes in wastewater remediation. Herein, the “alloy” networks which were fabricated by incorporating zeolitic imidazolate framework-67 (ZIF-67) into porous organic polymers (POPs) matrix, was demonstrated, following pyrolyzed to prepare a core-shell Co@N-doped carbon-based catalyst (Co@NC-HBPC). The catalytic activity of Co@NC-HBPC for peroxymonosulfate (PMS) was regulated by modulating the preferential cobalt facet orientation, which in turn could be modulated by adapting the incorporation of ZIF-67. The as-prepared Co@NC-HBPC showed desirable Co dispersion, high catalytic reactivity (over 97 % degradation of Nitenpyram (NTP) within 20 min), high stability (maintaining 89.8 % NTP oxidation in five cycles), and wide environmental adaptability towards Fenton-like reaction. Both quenching and probe experiments verified the dominant roles of hydroxyl radicals (^•OH) and singlet oxygen (¹O₂) species in NTP degradation process. Texture coefficient (TC) analysis and theoretical calculations unraveled that the Co (200) facet displayed the highest activity for PMS activation, which could modulate the surface electronic structure of N-doped carbon layer shell. This study provides comprehensive insights into the synergistic effect of metal facet and material morphology in PMS activation, thus offering new prospects for designing highly efficient heterogeneous catalysts for environmental remediation.