Ni Foam Supported Pd-Doped Zinc Spinel Oxide Nano-Electrocatalyst for Efficient Hydrogen Production Supported by DFT Study as Well Validated With Experimental Data

Abstract

An innovative palladium-doped zinc cobalt oxide nanoelectrocatalyst, ZnPd_xCo_2-xO₄ (0.00 ≤ x ≤ 0.08)@NF, is successfully synthesized using a hydrothermal method. The resulting material exhibits a spinel oxide phase, as confirmed by X-ray diffraction (XRD). The electrocatalytic performance of ZnPd_xCo_2-xO₄ (0.00 ≤ x ≤ 0.08)@NF is evaluated for the hydrogen evolution reaction (HER). The results show significant improvements in efficient hydrogen production, with an overpotential of 31 mV, a Tafel slope of 54.36 mV dec⁻¹, and sustained stability for over 72 h, using chronopotentiometry methods. Doping with 8.0% Pd concentration enhances the highest electrochemical performance of the nanoelectrocatalyst, supporting the idea that Pd doping improves HER activity. The results suggest that the increased electrochemical active surface area (ECSA) and faster charge transfer kinetics at the interface between the semiconductor and electrolyte contribute to enhanced performance. The DFT calculations performed in this work confirm the role of Pd in improving the catalytic activity of the ZnCo₂O₄ spinel catalyst. Overall, this study has made a significant contribution to the development of sustainable energy solutions, offering a promising path toward the efficient production of hydrogen fuel.