Identification of Co-O-Mo Active Centers on Co-Doped MoS₂ Electrocatalyst

Strategies for harmonizing the construction of an active site and the building of electron transport for a hybrid MoS₂ catalyst are crucial for its application in electrochemical reactions. In this work, an accurate and facile hydrothermal strategy was proposed to fabricate the active center of Co-O-Mo on a supported MoS₂ catalyst by forming a CoMoSO phase on the edge of MoS₂, yielding (Co-O)-MoS (x = 0, 0.3, 0.6, 1, 1.5, or 2.1). The results show that the electrochemical performances (hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and electrochemical degradation) of the yielded MoS₂-based catalysts were positively correlated with the Co-O bonds, verifying the significant role of Co-O-Mo as the active center. The fabricated (Co-O)-MoS_0.9 presented an extremely low overpotential and Tafel slope in both HER and OER, and it also demonstrated excellent BPA removal in the electrochemical degradation reaction. As compared with the Co-Mo-S configuration, the configuration of Co-O-Mo not only serves as the active center but also provides a conducting channel to facilitate electron conductivity with more accessible charge transfer at the electrode/electrolyte interface, which is favorable for electrocatalytic reaction. This work offers a new perspective for the active mechanism of metallic-heteroatom-dopant electrocatalysts and further boosts research on the development of noble/non-noble hybrid electrocatalysts in the future.