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 CeO2 nanorods (Ce0.05-NiFe@CeO2) 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 CeO2 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 Ce0.05-NiFe@CeO2 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.