Activation of peroxydisulfate by a novel Cu⁰-Cu₂O@CNTs composite for 2, 4-dichlorophenol degradation

In this study, a novel Cu⁰-Cu₂O@CNTs composite was synthesized, characterized and applied to activate peroxydisulfate (PDS) for the degradation of 2, 4-dichlorophenol (2,4-DCP) in contaminated lake water. The results indicated that Cu⁰-Cu₂O@CNTs can effectively activate PDS to produce O₂•^- radical, which has high selectivity to degrade organic pollutants in actual contaminated water. The efficiency of 2,4-DCP degradation and mineralization was 99.27% and 66.90%, respectively under the optimal condition. In the presence of Cl^-, HCO₃^- and natural organic matters (NOMs) or in real wastewater containing 2,4-DCP, Cu⁰-Cu₂O@CNTs/PDS system had a good selectivity for 2,4-DCP degradation. O₂•^- was the dominant reactive species in Cu⁰-Cu₂O@CNTs/PDS system for 2,4-DCP degradation. The possible degradation pathway of 2,4-DCP was proposed. It was concluded that Cu⁰-Cu₂O@CNTs composite could overcome the shortcomings of PDS activation by Cu⁰ and Cu₂O alone, such as low activating capability of Cu⁰ and instability of Cu₂O, which was high efficient for activating PDS. Cu⁰-Cu₂O@CNTs composite can be used as an efficient catalyst to activate PDS for the degradation of toxic organic pollutants in water and wastewater.