Heteroatom Substitution Enhances Generation and Reactivity of Surface-Activated Peroxydisulfate Complexes for Catalytic Fenton-like Reactions

Peroxydisulfate (PDS)-based Fenton-like reactions are promising advanced oxidation processes (AOPs) to degrade recalcitrant organic water pollutants. Current research predominantly focuses on augmenting the generation of reactive species (e.g., surface-activated PDS complexes (PDS⁎)) to improve treatment efficiency, but overlooks the potential benefits of enhancing the reactivity of these species. Here, we enhanced PDS⁎ generation and reactivity by incorporating Zn into CuO catalyst lattice, which resulted in 99% degradation of 4-chlorophenol within only 10 min. Zn increased PDS⁎ generation by nearly doubling PDS adsorption while maintaining similar PDS to PDS⁎ conversion efficiency, and induced higher PDS⁎ reactivity than the common catalyst CuO, as indicated by a 4.1-fold larger slope between adsorbed PDS and open circuit potential of a catalytic electrode. Cu-O-Zn formation upshifts the d-band center of Cu sites and lowers the energy barrier for PDS adsorption and sulfate desorption, resulting in enhanced PDS⁎ generation and reactivity. Overall, this study informs strategies to enhance PDS⁎ reactivity and design highly active catalysts for efficient AOPs.