Engineering active sites in ternary CuNiPd alloy electrocatalysts supported on nickel foam for improved electrochemical water splitting

The progress in electrochemical water splitting necessitates robust, efficient, and bifunctional catalysts to enable economical green hydrogen production. For this purpose, designing economically viable electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial for modern energy-conversion technology. In this work, we fabricated ternary CuNiPd (CNP) alloy on nickel foam (NF) as a support using a straightforward aerosol-assisted chemical vapor deposition method (AACVD). The deposition was carried out for varying durations of 1, 2, 3, and 4 h (CNP-1, CNP-2, CNP-3, and CNP-4) to tailor the fabricated catalyst into a range of nanostructures. Among all, the CNP-3 catalyst achieved a mulberry-like structure, demonstrating excellent catalytic performance for HER and OER. It reached 10 mA cm⁻² at overpotentials of 56 mV and 256 mV, with small Tafel slopes of 28 mV dec^-1 and 23 mV dec^-1, respectively. Meanwhile, this catalyst persistently performed HER and OER for 75 h under applied potentials of −1.75 V and 1.75 V (Vs RHE), respectively. The remarkable performance demonstrated by CNP-3 catalyst is credited to the synergy among the tri-metals (Cu, Ni, and Pd) on the surface of NF. This synergy resulted in enhanced activity, along with the mulberry morphology providing abundant active sites, rendering it highly efficient for catalyzing HER/OER and other potential electrochemical applications.