Ni₂P/CeO₂/rGO//AC Hybrid Nanocomposite with Electrostatic–faradaic Synergy for Bifunctional Energy Storage and Advanced Electrocatalytic Applications

With the rise of worldwide energy consumption and demands the researches are turning to sustainable and renewable energy technologies based on multifunctional material for energy conversion and storage. The most pivotal aspect of this transition is advancing the electrocatalytic systems to efficient, economical, and more durable technologies. In the present study, we have focused on the synthesis of multifunctional Ni₂P/CeO₂/rGO-based nanocomposite as advanced electrode material, and systematically evaluated its structural, morphological, and electrochemical properties. The crystalline structure, phase purity, oxidation states of constituent elements, and chemical bonding environments of the prepared material were studied. The Ni₂P/CeO₂/rGO-electrode demonstrated the highest specific capacity (Cs) of 1638 C/g, excellent rate performance, and outstanding stable cycling response. Ni₂P/CeO₂/rGO//AC assembled asymmetric battery hybrid supercapacitor (BHSC), system exhibited energy and power (Ed, Pd) densities of 45 Wh kg−1 and 2613 W kg−1, with the highest specific capacity of 378 C g−1, while maintaining excellent long-term operational stability. The Ni₂P/CeO₂/rGO-electrode was further studied for its applicability in overall water splitting, presenting the low overpotentials of 1.51 V, and −0.192 V, and Tafel slopes of 69 mV dec−1 and 91 mV dec−1, for hydrogen evolution (HER) and oxygen evolution (OER) reactions, along with durable catalytic performance. The present detailed study highlights the strong potential of the Ni₂P/CeO₂/rGO electrode for advanced energy storage and conversion systems with excellent efficiency, reproducibility, stability, and scalability applications.