Modulation of the pyrolysis of ZIF-67 by kaolinite for highly efficient peroxymonosulfate activation

Abstract

The persistent challenge of organic pollutant remediation drives the development of sulfate radical-based advanced oxidation processes, where heterogeneous cobalt-based catalysts face critical stability limitations. To address this, we rationally designed kaolinite-supported carbon-coated cobalt composites through calcination of ZIF-67/Kaol precursors, achieving enhanced peroxymonosulfate (PMS) activation for atrazine degradation. The engineered catalyst combines lamellar structure and active surface groups of kaolinite with ZIF-67-derived nitrogen-doped carbon frameworks, exhibiting exceptional catalytic performance. Mechanistic studies reveal singlet oxygen as the exclusive reactive species, with nitrogen doping in the carbon matrix substantially enhancing charge density and electron transfer efficiency. The carbon coating facilitates electron redistribution while protecting active cobalt sites, enabling sustained catalytic cycles. This work establishes a materials design paradigm combining mineral support engineering with metal-organic framework derivation strategies, demonstrating significant potential for developing robust PMS activation systems in water remediation applications.