MOF-Derived Copper and Manganese Oxides: Highly Effective PMS Activator for Rhodamine B Removal

In PMS catalytic oxidation studies, we design and prepare a Mn₃O₄/CuO (CMO-2) composite catalyst using metal–organic frameworks (MOFs) as precursors. Compared with Mn₃O₄, its activated per-oxy-monosulfate activation catalyzed the degradation of pollutants with nearly six times higher activity efficiency. The experimental findings demonstrate that CMO-2 derived from metal–organic frameworks offer the advantages of wide adaptability to solution pH, along with improved versatility, stability, and recyclability. Further experiments involving radical scavenging, electrochemistry, and electron spin resonance (EPR) techniques confirm that the CMO-2 derived from MOF structures exhibit more significant interfacial engineering effects. This leads to an expansion of active interfaces, enhancing the accessibility and dispersion of active sites. Consequently, it significantly improves the efficiency of electron-transfer reactions and promotes a wide range of reactive oxygen species (ROSs), including SO₄^•− •OH and¹O₂.

Based on the synergistic effect of copper-manganese bimetallic, the copper-manganese composite catalyst (CMO-2) prepared by doping 0.5 g of Cu-MOF showed the best catalytic activity in activating PMS, and the resulting ROS_S could efficiently degrade organic pollutants.