Nickel foam supported CuCo-MOF/g-C₃N₄ composite electrode for efficient overall water splitting

Developing electrocatalysts that are efficient, durable, and economically viable is essential for promoting sustainable hydrogen generation via water splitting. In the present study, a novel CuCo-MOF/g-C₃N₄ composite electrode supported on three-dimensional nickel foam (CuCo-MOF/g-C₃N₄-NF) was fabricated via a straightforward in situ synthesis approach for bifunctional electrocatalytic applications. The integration of a bimetallic copper–cobalt metal–organic framework (CuCo-MOF) with graphitic carbon nitride (g-C₃N₄) on a 3D nickel foam substrate results in a highly porous architecture with abundant electroactive sites, enhanced electrical conductivity, and improved mass transport characteristics. The CuCo-MOF/g-C₃N₄ composites, synthesized through a solvothermal route, exhibited remarkable bifunctional electrocatalytic activity toward overall water splitting. The CuCo-MOF/g-C₃N₄-NF electrode exhibited low onset potentials of 1.47 V for OER and − 0.10 V for HER at a current density of 10 mAcm⁻², showing superior performance compared to the individual Cu-MOF, Co-MOF, and CuCo-MOF catalysts in 1 M KOH solution. Furthermore, the composite displayed low Tafel slopes (87.9 mV dec⁻¹ for OER and 159 mV dec⁻¹ for HER), minimal charge-transfer resistance, and excellent stability over 60 h of continuous operation. These results demonstrate that the CuCo-MOF/g-C₃N₄-NF composite is a highly promising, scalable, and cost-effective electrocatalyst for green hydrogen generation via overall water splitting.