CeO₂/mixed transition metal oxide nanostructures immobilized on Ti₃C₂T_X MXene for boosting electrochemical water oxidation

Metal oxides on MXene layers are used as efficient electrode materials for water oxidation. In this study, CeO₂/NiO/Co₃O₄@MXene (CNCM) nanocomposites were synthesized and investigated as modified nickel foam (NF) electrodes for water oxidation. In a 1.0 M KOH electrolyte solution, the CNCM(5:1) nanocomposite achieved a low overpotential of 365 mV at a current density of 100 mA cm⁻², a Tafel slope of 57 mV dec⁻¹, and a charge transfer resistance of 0.39 Ω cm². It demonstrated significantly improved performance compared to its constituents and other combinations with the same weight ratio of nanoparticles to MXene. CNCM(5:1) also exhibited high stability during chronopotentiometry at a current density of 25 mA cm⁻² over 24 h. Furthermore, it effectively served as both anode and cathode materials in an overall water splitting (OWS) system, achieving a cell voltage of 1.83 V and maintaining stability for at least 10 h.