Electrodeposition of NiCo Layered Double Hydroxide on Diverse Substrates: Structural, Morphological, and Electrochemical Insights into OER Performance in Alkaline Medium

Developing highly efficient and stable electrocatalysts for the oxygen evolution reaction (OER) is crucial for enhancing the performance of water-splitting systems. This work explores the electrodeposition of nickel–cobalt layered double hydroxide (NiCo LDH) on three distinct substrates such as nickel foam (NF), graphite sheet (GS), and carbon cloth (CC) to assess the impact of substrate choice on catalytic performance. Structural and morphological analyses confirmed the uniform deposition of NiCo LDH with well-defined nanosheet-like structures. Electrochemical studies such as linear sweep voltammetry (LSV), Tafel slope determination, electrochemical double-layer capacitance ( C dl ), electrochemical impedance spectroscopy (EIS), and chronopotentiometry were used to assess the performance of the fabricated NiCo LDH electrodes toward the OER activity. Among the tested substrates, NiCo LDH/NF demonstrated the best catalytic activity, demanding an overpotential of 260 mV to reach a current density of 50 mA/cm 2, with a Tafel slope of 57 mV/dec and a C dl value of 2.86 mF/cm 2, indicating favorable charge transfer characteristics. Moreover, long-term stability assessments revealed that NiCo LDH/NF retained 99% of its initial activity after 100 cycles of cyclic voltammetry. The overall cell potential resulted in 1.61 V at 10 mA/cm 2 . These results underscore the importance of choosing the appropriate substrate in optimizing the electrocatalytic efficiency of NiCo LDH for water-splitting applications.