Interfacial Synergy in CeO₂-Decorated MgAl-LDH Heterostructures for Enhanced Oxygen Evolution Reaction

Designing efficient, durable, and cost-effective electrocatalysts for the oxygen evolution reaction (OER) remains a critical challenge in the development of advanced water-splitting technologies. Herein, a series of CeO₂-decorated MgAl-layered double hydroxide (LDH) heterostructures were rationally synthesized via a facile hydrothermal approach. Structural and morphological characterizations confirm the successful integration of CeO₂ nanoparticles onto the LDH nanosheets without compromising the layered architecture. Among the synthesized catalysts, the C-5L heterostructure exhibits superior OER performance in 1 M KOH, requiring an onset potential of 0.28 V and overpotential of only 0.32 V to deliver a current density of 10 mA cm^-2, significantly lower than its undoped and higher doped counterparts. The optimized catalyst also achieves the smallest Tafel slope (80 mV dec^-1), the lowest charge-transfer resistance (34 Ω), and the highest C_dl (4.21 mF cm^-2), indicating enhanced reaction kinetics and increased electrochemically active surface area. Furthermore, it demonstrates the highest mass activity (28 A g^-1 at 0.37 V vs. RHE) and exceptional operational stability over 100 h at 100 mA cm^-2. This study underscores the theme of interfacial engineering between CeO₂ and LDH, providing valuable insights into designing high-performance OER catalysts through controlled electronic coupling and defect modulation.