In situ synthesis of Tree-branch-like Copper-manganese oxides nanoarrays supported on copper foam as a superior efficiency Fenton-like catalyst for enhanced degradation of 4-chlorophenol

Recently, considerable attention has been paid to develop novel Fenton-like oxidation systems for environmental remediation. The activation of periodate (NaIO4) is a desirable oxidation process that drive redox reactions to produce abundant reactive oxygen species (ROS) by a suitable activator. This study reports a simple hydrothermal-calcination route for forming novel tree-branch-like copper-manganese oxides (CuMnOx@MnOx, CMM) nanoarrays, and the production of radical species from NaIO4 induced by CMM for the removal of rhodamine B and 4-chlorophenol from wastewater. The synergistic effects of Cu oxides and Mn oxides composite significantly elevated the activation of periodate, exhibited excellent degradation performance in the CMM/NaIO4. Furthermore, reduced copper species and mixed-valence manganese species play a major role in reaction via XPS analysis. Additionally, the underlying degradation mechanism of this work was systematically researched by radical quenching tests and EPR analysis. Superoxide anion radical (O2−) was the major free radicals in this system, simultaneously the production of non-radical singlet oxygen (1O2) via the electron transfer, which are contributed to remove organic pollutants. This work provides a facile way for fabricating monolithic multi-component metal oxides, and new insights into understand activation mechanism of manganese-based periodate activator.