Modulating the Local Electronic Structure of NiFe LDH by Ce-Doping and Interfacial Coupling of CeO₂ Nanorods for Efficient Water Oxidation

Transition metal layered double hydroxides (LDHs) are widely used catalysts for the alkaline oxygen evolution reaction (OER), yet their catalytic activity and long-term stability remain challenging. Herein, we report a cerium-doped NiFe LDH nanosheet supported on CeO 2 nanorods (Ce 0.05 -NiFe@CeO 2 ) successfully synthesized by hydrothermal and simple co-precipitation methods for water oxidation. We demonstrate that Ce-doping promotes the oxygen vacancies and modifies the electronic structure of NiFe LDH, leading to improved adsorption and desorption of reaction intermediates. Crystalline CeO 2 NR provides structural stability, increases the active surface area, and facilitates the interfacial interaction between the LDH layer and substrate, enhancing catalytic performance. As a result, the Ce 0.05 -NiFe@CeO 2 heterostructure exhibits remarkable OER performance in basic media, requiring an overpotential of only 217 mV to drive a current density of 100 mA cm –2 with excellent durability over 96 h at a large current density of 250 mA cm –2 . Moreover, the heterostructure exhibited a very low Tafel slope of 15.56 mV dec –1, being 5 times lower than that of pristine NiFe LDH. Our work effectively advances the catalytic activity of the well-studied NiFe LDH well beyond its current limit in the OER catalysis, further creating a path for the rational design of the OER electrocatalysts.