Modulation of the CuxO structure and morphology for acceleration of peroxymonosulfate oxidation†

Abstract

Peroxymonosulfate (PMS) activation technology represents a novel advancement within advanced oxidation processes (AOPs), garnering significant attention in recent years for its efficacy in treating recalcitrant organic pollutants. This study focused on the synthesis of Cu_xO catalysts via a one-pot solvothermal method. The investigation mainly evaluated the influence of solvents on the microstructure and morphology of the Cu_xO catalyst. Microstructural analysis revealed that ethanol as a solvent could effectively modulate the surface microstructure, enhancing pore formation and increasing specific surface area, thereby optimizing the catalytic performances of Cu_xO catalysts. Compared with other parameters such as initial pH and solvothermal temperature, the solvent was the key factor in the solvothermal process. The influences of catalyst dosage and PMS concentration on the catalyst's performance were explored and discussed. In addition, the pH and temperature of the solution and coexisting anions were investigated as environmental factors. Radical burst experiments confirmed the presence of sulfate radicals (SO₄˙⁻) and hydroxyl radicals (˙OH) within the reaction system, with SO₄˙⁻ identified as the predominant species driving the degradation process. Furthermore, repeatability testing demonstrated the catalyst's stability. This research not only strengthened understanding of the PMS activation mechanism by Cu_xO but also proposed novel avenues for future catalyst design and optimization.