Duo-functional Ce-NiFe LDH/graphene oxide catalyst for high-performance water electrolysis

The oxygen evolution reaction (OER) is widely recognised as the rate-determining step for water electrolysis reactions. Here, we report a transition-metal-based Ce-NiFe layered double hydroxides supported on graphene oxide (Ce-NiFe LDH/GO) electrocatalyst that exhibits promising OER activity, high conductivity and enhanced hydrogen evolution reaction (HER) performance. The electronic structure is tuned via Ce doping-induced lattice distortion. Furthermore, the GO serves as a conductive scaffold that suppresses nanosheet agglomeration, enabling the construction of the highly integrated Ce-NiFe LDH/GO architecture. The optimized catalyst shows ultralow overpotentials of 189 mV for HER and 126 mV for OER at 10 mA cm −2 , with corresponding Tafel slopes of 80.1 mV dec −1 and 49.3 mV dec −1 . When employed as a bifunctional electrocatalyst in an alkaline electrolyser, the system requires only 1.74 V to achieve 10 mA cm −2 , and retains more than 98% of its initial activity after 24 h of continuous operation, demonstrating excellent durability. Combined XPS and EIS analyses reveal a synergistic enhancement mechanism. Specifically, XPS analysis validates that Ce incorporation tunes the electronic structure of Ni/Fe centres to optimise intermediate adsorption, whereas EIS results indicate that the GO scaffold minimises charge transfer resistance, ensuring superior conductivity and structural integrity.