Enhanced oxidation of 2,4-dichlorophenol in ferrate(VI) and copper oxide system via the formation of trivalent copper ion and singlet oxygen.

Abstract

Improving the activity of ferrate is one of the main research focus in environmental field. Here, we demonstrate a novel copper oxide (CuO)-Ferrate(VI) system wherein CuO plays a key role in activating Fe(VI) to effectively eliminate phenolic contaminants. The dominant reactive species were determined to be Cu(III) and ¹O₂, confirmed by in situ Raman spectroscopy, quenching experiments, and EPR tests. The results indicated that Fe(VI) preferentially reacts with CuO, forming Cu(III) and ¹O₂. Subsequently, deprotonated 2,4-dichlorophenol (2,4-DCP) was adsorbed with Cu(III) via electrostatic adsorption and was directly oxidized by Cu(III). Co-existing ion experiments demonstrated the strong stability of the CuO/Fe(VI) system against environmental background substances, maintaining effective removal efficiency over multiple cycles. In summary, this study highlights the potential advantages of CuO-assisted Fe(VI) activation, offering a new route for the efficient utilization of Fe(VI) in eliminating phenolic pollutants.