Constructing Asymmetric M-S-Mo Active Sites to Boost Efficient Peroxymonosulfate Activation for Water Purification.

Enhancing the activation efficiency of peroxymonosulfate (PMS) to generate more reactive oxygen species (ROS) is crucial for improving the catalytic performance of Fenton-like reactions. Strategies on the regulation of active sites and the enhancement of interfacial electron transfer from catalysts to PMS have become central to achieving effective PMS activation in Fenton-like catalysis. In this work, single-atom M-doped sulfur vacancies (S)-MoS (M = Co, Mn, Ni, Cu, and Zn) catalysts with atomic-level asymmetric M-S-Mo sites are proposed for efficient PMS activation and the degradation of organic pollutants. Among these catalysts, the Co-S-MoS exhibited excellent catalytic activity and stability, resulting in a removal efficiency of ≈100% for Rhodamine B (RhB) within just 6 min. Density functional theory (DFT) calculations revealed the construction of asymmetric Co-S-Mo sites effectively enhanced the electron density near the Fermi level, facilitated more electron transfer to PMS as well as lengthened the O-O bond of PMS, thereby significantly promoting the generation of ROS. This work provides a strategy for regulating atomic-level active sites and a novel perspective for developing advanced Fenton-like catalysts.