Nickel-Coated Copper Foam Electrocatalytic Electrode for Energy-Saving Hydrogen Evolution and Value-Added Chemical Cogeneration.

Developing cost-effective, eco-friendly electrocatalysts is essential for enhanced water electrolysis. The efficient, affordable, and earth-abundant electrocatalysts like 3D copper foam (CuF) provide ideal porous structures for rapid ion transport during water electrolysis. In this study, a bimetallic foam architecture (CuF@Ni) is fabricated by electrodeposition of Ni on CuF. This structure acts as both conductive support and active catalyst during the water electrolysis process. The synthesized CuF@Ni demonstrated superior hydrogen evolution reaction (HER) activity with an overpotential of 0.18 V at 50 mA cm-2, while the methanol oxidation reaction (MOR) overpotential exhibits 0.14 V at 50 mA cm-2 current density. CuF@Ni electrocatalytic electrode achieved a Faradaic efficiency ≈100% during 150 C charge transfer. In a co-generation system, the onset potential is observed as lower 0.4 V, and CuF@Ni required only 0.92 V to sustain the current density of 50 mA cm-2, demonstrating significant energy savings. Furthermore, this device consumes less power than theoretical water electrolysis under higher current density. The electrochemical stability of 100 h and 120 h achieved for HER and MOR, respectively, confirmed minimal degradation under the harsh conditions. This study highlights CuF@Ni as a promising dual-functional electrocatalyst for efficient energy conversion and future renewable energy applications.