Efficient rGO-supported CeO₂–Y₂O₃–Nd₂O₃ nanocomposite electrocatalyst for water splitting (HER/OER) in alkaline medium

Increasing demand for hydrogen as fuel from the electrolysis of water, along with the immense use of alternative energy strategies, is vital to meet future energy demands. Herein, we report the very first time that a quaternary composite CeO₂–Y₂O₃–Nd₂O₃ modified with rGO support on nickel foam substrate demonstrated excellent catalyst behavior. Systematic structural and morphological studies are performed to understand the effects of the rare-earth-based elements on hydrogen and oxygen evolution reactions in an alkaline (1.0 M KOH) electrolyzer. X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of multiple valence states, synergistic interaction, and electronic effects between the prepared nanocomposite components, resulting in excellent catalytic activity. The quaternary composite has excellent OER/HER characteristics than individual oxides with low overpotential 272 mV (OER) and 303 mV (HER) to produce standard 10 mAcm⁻² current density. Moreover, the quaternary composite catalyst with more active sites also displayed a larger surface area (9.03 cm²) and double-layered capacitance (36.12 mF). The corresponding electrode is efficient and maintains its stability over 50 h toward OER/HER, which can greatly contribute to practical operation. Graphical abstract: (Figure presented.).