Work

A Molecular Assembly Promotes Reactivity of Cobalt Redox Intermediates in Electrochemical Oxygen Evolution

Year: 2025

Type: article

Abstract: To optimize the intrinsic activities of catalytic sites at high surface density is crucial for advancing heterogeneous molecular electrocatalysis. However, it remains elusive due to a lack of an appropriate heterogenization strategy in the catalyst design using ubiquitous graphitic supports. Herein, oxidized molybdenum disulfide nanodots (MoSO x ‐d) with abundant sulfates edges are identified as efficient linkers to molecular Co‐2, 2′‐bipyridine (Co(py) 2 ) complexes, enabling a relatively high surface density of heterogenous Co sites. The sulfates tuned the Co sites from first to second spheres by forming a CoO 2 S coordination linkage, which resulted in a moderately reactive HO‐Co 3+ ‐OH intermediate in a Co 2+ , Co 3+ to Co 4+ redox‐mediated pathway for oxygen evolution. This improved the intrinsic turnover frequencies (TOFs) of Co sites compared to ones grafted on common graphitic supports, as well as pristine molybdenum disulfide. A relatively low overpotential (η) of 314 mV is achieved at a current density of 10 mV cm −2 . These results establish a straightforward bottom‐up strategy for constructing molecularly well‐defined and surface‐dense active sites for high‐performance electrocatalysis.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202509426