Cerium modified NiFe-LDH as bifunctional electrocatalyst for efficient OER and UOR

Rare-earth doping serves as an effective strategy to tune the catalytic behavior of layered double hydroxides (LDHs). Herein, Ce-doped NiFe-LDH was grown on nickel foam via a facile one-step hydrothermal method as a high-performance bifunctional electrocatalyst toward oxygen evolution reaction (OER) and urea oxidation reaction (UOR). Structural, compositional, electronic characterizations and DFT calculations reveal that reveal that the Ce 3+ doping regulates the d ‑band center of metal centers to optimize intermediate adsorption strength and lower reaction energy barriers, simultaneously triggers reversible Ce 3+ /Ce δ+ (δ＞3) redox cycles for accelerated interfacial electron transfer and generation of high‑valent Ni 3+ . As a result, the CeNiFe‑LDH delivers an OER overpotential of 257 mV at 100 mA cm -2 with a Tafel slope of 51.4 mV dec -1 , and maintains stable OER current for 28 h at 1.8 V vs. RHE with no obvious decay. For UOR, it achieves 100 mA cm -2 at 1.36 V vs. RHE in 1 M KOH containing 0.33 M urea. Assembled into a two-electrode electrolyzer, the device achieves cell voltage of 1.82 V at 100 mA cm -2 . This work provides a simple and effective route for constructing rare-earth modified LDH-based bifunctional electrocatalysts for energy-saving electrolysis systems.