Revealing the Intrinsic Peroxidase-Like Catalytic Mechanism of Heterogeneous Single-Atom Co-MoS.

The single-atom nanozyme is a new concept and has tremendous prospects to become a next-generation nanozyme. However, few studies have been carried out to elucidate the intrinsic mechanisms for both the single atoms and the supports in single-atom nanozymes. Herein, the heterogeneous single-atom Co-MoS (SA Co-MoS) is demonstrated to have excellent potential as a high-performance peroxidase mimic. Because of the well-defined structure of SA Co-MoS, its peroxidase-like mechanism is extensively interpreted through experimental and theoretical studies. Due to the different adsorption energies of substrates on different parts of SA Co-MoS in the peroxidase-like reaction, SA Co favors electron transfer mechanisms, while MoS relies on Fenton-like reactions. The different catalytic pathways provide an intrinsic understanding of the remarkable performance of SA Co-MoS. The present study not only develops a new kind of single-atom catalyst (SAC) as an elegant platform for understanding the enzyme-like activities of heterogeneous nanomaterials but also facilitates the novel application of SACs in biocatalysis.