CuCo carbon aerogel as a bifunctional cathode for Electro-Fenton processes: Unveiling synergistic effects and catalytic mechanisms

Combining electrocatalytic oxygen reduction reaction (ORR) and heterogeneous electro-Fenton (HEF) is considered a promising approach for generating reactive radicals to decompose organic micropollutants in water. A novel catalyst, copper-cobalt carbon aerogel (CuCo/CA), was successfully fabricated and directly applied as a bifunctional cathode in an HEF system. The synergistic effect of Cu and Co contributed to the development of distinctive microstructures, including abundant oxygen-containing groups, carbon defects, a large surface area and a unique porous structure. These structural features endowed CuCo/CA with rapid electron transfer capability and enhanced activity and selectivity for the two-electron ORR process. In the constructed EF system, CuCo/CA achieves its dual functionality by catalysing the electrosynthesis of hydrogen peroxide and its in-situ activation to generate highly reactive hydroxyl radicals. Notably, anodic oxygen evolution in the system eliminated the need for additional oxygen input, enhancing its cost-effectiveness. The system demonstrated degradation ability for a range of candidate organic pollutants, including antibiotics, analgesics, organic acid and dye. After six consecutive runs, CuCo/CA EF system achieved satisfactory TC removal and good adaptability within a broad pH range. Long-term stability and low electricity consumption highlighted the potential of CuCo/CA as an efficient and sustainable cathode in EF technology for water decontamination.