Self-Supported Co₃S₄/Ni₃S₂@Carbon Cloth Electrocatalysts Derived from Metal–Organic Frameworks for Efficient Urea and Ethanol Electrooxidation in Alkaline and Seawater Electrolysis

Metal-organic framework (MOF) materials have been extensively utilized in water electrolysis owing to their versatile chemical configurations and three-dimensional porous and exceptional surface areas characteristics. This study implemented an MOF-derived synthesis approach to develop a self-supporting electrocatalytic system. Initially depositing nanostructures on flexible carbon cloth through controlled growth, subsequent thermal treatment, and solution-phase sulfurization processes generated the Co3S4/Ni3S2@CC composite. The engineered material demonstrates hierarchical porosity and synergistic interfacial effects between components, facilitating numerous catalytic centers and optimized electron transport pathways. Strategic sulfur incorporation successfully tailors the electronic environment, substantially boosting the reaction kinetics. The integrated heterointerface electrode manifests superior dual-functional performance in alkaline freshwater electrolysis, demonstrating remarkably low overpotentials of 169 mV (HER) and 294 mV (OER), respectively, to attain a 10 mA cm-2 current density, while maintaining excellent durability under continuous operation. When operating in saline environments, the catalyst demonstrates remarkable catalytic activity, exhibiting overpotentials of 177 mV for the HER and 323 mV for the OER under identical current density conditions. Introducing ethanol or methanol into the electrolyte system significantly reduces the activation potential and lowers the overall energy requirements. These findings provide crucial guidance for developing advanced MOF-derived transition metal electrocatalysts optimized for efficient water splitting applications.