Mos2/Nixsy/Nf Heterojunction Catalyst for Efficient Oxygen Evolution Reaction

The development of highly efficient and stable non-noble metal catalysts is crucial for advancing the Oxygen Evolution Reaction (OER). In this study, a flower-branch-like MoS2/NixSy/NF heterostructure was synthesized using a one-step hydrothermal method as an effective OER electrocatalyst. X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) confirmed the heterojunction's presence and nickel's shift to a higher oxidation state. The heterojunction enhanced electronic interactions, enriched active sites, and facilitated electron transfer, while the Ni3+ promoted OH- adsorption, boosting OER kinetics. Additionally, SO42- leaching during OER may aid the conversion of nickel sulfide to the active NiOOH species, further improving performance. The MoS2/NixSy/NF catalyst showed a low overpotential of 150 mV at 10 mA×cm-2 and a Tafel slope of 61 mV×dec-1, indicating excellent activity. It also demonstrated remarkable stability, with negligible decay after 50 hours under alkaline and simulated seawater conditions. This work underscores the importance of heterojunctions in enhancing electrocatalyst performance for OER and the key role of heterojunctions in improving electrocatalyst performance, which offers new insights for designing high-performance OER electrocatalysts.