Highly efficient degradation of phenol from wastewater via an electro-catalytic oxidation approach with a CeO(2)–CuO cathode

The development of highly efficient cathode materials for the electro-catalytic oxidation of phenol from wastewater is of vital importance for environment protection. Herein, we develop an effective CeO(2)–CuO electrocatalyst for 2-electron oxygen reduction reaction (ORR) to generate H(2)O(2), and then applied it as the cathode for the electro-catalytic oxidation of phenol. Results showed that the CeO(2)–CuO cathode with different contents of CuO exhibited a higher yield of H(2)O(2) than those of CuO and CeO(2), and the highest yield of H(2)O(2) (114 mg L(−1)) was achieved with a CuO content of 13.4%. The resultant CeO(2)–CuO-13.4% cathode demonstrated a high degradation rate of 91% after 180 min, which was 1.82-fold and 1.52-fold higher than pure CuO (50%) and CeO(2) (60%) electrodes, respectively. Furthermore, the degradation rate of phenol via the electro-catalytic oxidation technology by using a CeO(2)–CuO cathode significantly outperformed that of the chemical oxidation approach. The outstanding degradation performance of the CeO(2)–CuO cathode is attributed to the high yield of H(2)O(2) and the strong interaction of CeO(2) and CuO.