The slow process of oxygen evolution reaction (OER) and the high cost of noble metal oxide catalysts have hindered the widespread application of environmentally friendly electrochemical water splitting for hydrogen production. Therefore, the emergence of effective transition metal-based electrocatalysts for the hydrogen evolution reaction (HER) and urea oxidation reaction (UOR, as an alternative to OER) is crucial for large-scale sustainable electrochemical hydrogen production. In this study, an active, effective, and stable CoMnS@NiCo/NF electrode was synthesized using a binder-free and efficient two-step electrodeposition method as a multifunctional electrode for HER and UOR. Taking advantage of the large active surface area, interconnected pores and porosity, the synergistic effect between elements, accelerated charge, and mass transfer, the synthesized CoMnS@NiCo/NF electrode showed unique electrochemical activity over 5 cycles. This electrode exhibited excellent HER activity with 138 mV overpotential at 100 mA.cm−2. In addition, for the UOR process, the required voltage in 100 mA.cm−2 was 1.37 V vs. RHE. Also, the bi-functional activity of this electrode in the HER/UOR process was also outstanding, with 1.55 V cell voltage at 100 mA.cm−2. To evaluate its industrial performance, the electrocatalytic stability tests showed satisfactory results. Spin-polarized density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations demonstrate that sulfur incorporation leads to local amorphization and electronic redistribution, effectively tuning the d-band position of Co/Mn active sites. This enhanced activation-desorption balance markedly increases HER and UOR catalytic performance. This study provides new strategies and insights for the synthesis of active and stable electrocatalysts in energy conversion systems.

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