Magnetic CuO@Fe3O4 nanocomposite as a highly active heterogeneous catalyst of persulfate for 2,4-dichlorophenol degradation in aqueous solution

Abstract

A new magnetic CuO@Fe₃O₄ nanocomposite was fabricated through an impregnation method and then characterized through X-ray diffraction, high-resolution transmission electron microscopy, nitrogen adsorption–desorption, and energy dispersive X-ray spectroscopy. The effects of initial solution pH, catalyst addition, reaction temperature, target contaminant, and persulfate (PS) concentration on 2,4-dichlorophenol (2,4-DCP) degradation in the activated PS system with the composite was evaluated. Results showed that the composite can degrade 96.9% of 2,4-DCP after 180 min under the following reaction conditions: PS, 10 mM; CuO@Fe₃O₄, 0.624 g L⁻¹; 2,4-DCP, 100 mg L⁻¹; pH, 6.8 ± 0.3; and temperature, 30 °C. Quenching tests of different scavengers revealed that SO₄˙⁻ and ˙OH are responsible for 2,4-DCP degradation. The pseudo-first-order kinetic model was then established to describe 2,4-DCP mineralization. The composite also exhibited stable catalytic performance after using for three cycles, thereby indicating the promising application of the catalyst for remediation of water contaminated with 2,4-DCP.