Ce-doping optimized interface synergy in Co-Ce alloy/NiFe layered double hydroxide/carbon fiber paper heterostructure for boosted oxygen evolution reaction

Electrocatalytic water splitting offers a sustainable route for converting renewable electricity into green hydrogen. Transition-metal-based layered double hydroxide (LDH) catalysts are considered attractive candidates for oxygen evolution reaction (OER) catalysis. Nevertheless, their catalytic performance remains constrained by poor conductivity, limited affinity for oxygen intermediates, and unsatisfactory durability. Here, we report a self-supported Ce-doped Co alloy/NiFe layered double hydroxide heterostructure on carbon fiber paper (CoCe/NiFe-LDH/CP) fabricated by two-step electrodeposition, which owns a hierarchical fiber-nanoflower-nanoparticle architecture, and provides a hydrophilic/aerophobic surface. The optimized electrode delivers overpotentials of 190 and 249 mV at 10 and 100 mA cm⁻² with stable operation for 120 h and a Tafel slope of 27.4 mV dec⁻¹. The characterization results show that the establishment of the alloy/NiFe-LDH heterostructure enhances electrical conductivity while Ce doping strengthens the electronic coupling at the heterointerface and induces lattice distortion in the Co phase, thereby optimizing the adsorption behavior of oxygenated intermediates during OER, achieving synergistic regulation of electrical conductivity and oxygen-intermediate adsorption. Density functional theory further shows a reduced barrier for the Gibbs free energy together with a more appropriate interfacial d -band center, suggesting optimized intermediate binding at the alloy/LDH interface. This rare-earth-enabled alloy/LDH interface strategy provides a reference for designing high-performance OER anodes through coupled alloying and heterointerface engineering, offering a more integrated route than conventional single-factor optimization in OER catalysts.