Synergy enhancement of Co single atoms and asymmetric sub-nanoclusters for Fenton-like activation

As a new water treatment technology, Fenton-like reaction has great potential. In this study, we successfully prepared an excellent Fenton-like catalyst, which is composed of cobalt monoatoms and asymmetric subnanoclusters (labeled CoSA/Clu-C₂N), and exhibits excellent peroxymonosulfate (PMS) activation reactivity. By directly comparing the catalytic properties of CoSA-C₂N and CoSA/Clu-C₂N, the synergistic effects of coasymmetric Co subclusters and Co atoms on the activation of PMS and degradation of organic micropollutants were investigated. The results showed that CoSA/Clu-C₂N had higher degradation rates of carbamazepine (CBZ), antipyrine (AT) and chlorobenzoic acid (CA) when combined with active oxidant PMS. The cyclic frequency of CBZ was 5.4 min⁻¹, which was twice as high as the catalytic constant of CoSA-C₂N (2.4 min⁻¹). The results show that CoSA/Clu-C₂N cobalt subnanoclusters and cobalt single atom can synergistically improve the catalytic performance of activated PMS oxidation of micropollutants in water. In addition, electron paramagnetic resonance (EPR) technology has proved that the introduction of Co subnano clusters in CoSA/Clu-C₂N is conducive to the production of singlet oxygen (¹O₂), thereby improving the efficiency of pollutant oxidation. This work lays a solid foundation for the future design of advanced multifunctional catalysts by carefully regulating and combining monmetallic atoms and metal subnanoclusters.