Non-radical degradation of 2,4-dichlorophenol via periodate activation over semi-coke supported bimetallic MOF-derived carbon

Abstract

Using semi-coke (SC) as a support and Zn-Co metal-organic framework (MOF) as a precursor, an SC-loaded MOF-derived carbon-based catalyst (ZnCo-NC@SC) was prepared by a facile in-situ growth-pyrolysis method, and then used to activate periodate (PI) to degrade 2,4-dichlorophenol (2,4-DCP) in water. The effects of preparation conditions for ZnCo-NC@SC, initial pH, ZnCo-NC@SC and PI dosage, inorganic ions and organic matter, 2,4-DCP concentration and temperature on 2,4-DCP degradation were investigated. Under the optimized conditions, 2,4-DCP was removed by 97.89 % within 60 min and 92.63 % after 4th cycle. Furthermore, the ZnCo-NC@SC/PI system could effectively degrade 2,4-DCP at pH 3–9 and temperature 10–50 ℃, with a removal efficiency of > 95 %. This was a ¹O₂ and electron transfer dominated non-radical pathway, with the toxicity of intermediates closely correlated with the degradation pathway. This study provides a different approach to SC reutilization, reveals the mechanism of ZnCo-NC@SC for activating PI to remove 2,4-DCP, and the developed ZnCo-NC@SC/PI system has tremendous potential for application in real water bodies.