Nickel-based layered double hydroxide oxygen evolution electrocatalysts: From reaction mechanisms to design strategies and material modification

Given the global energy crisis and environmental challenges, water electrolysis for hydrogen production is critical for the low-carbon energy transition. However, the anodic oxygen evolution reaction (OER), suffering from sluggish kinetics and high overpotential, remains the key bottleneck restricting the overall efficiency of water electrolysis. Nickel-based layered double hydroxides (Ni-LDH) are promising non-noble metal OER electrocatalysts owing to their earth abundance, tunable structure, and abundant active sites. This review systematically summarizes recent advances in Ni-LDH-based OER electrocatalysts. It first elaborates on the core characteristics, structure-activity relationships, advantages and limitations of five representative OER mechanisms: the adsorbate evolution mechanism (AEM), the lattice oxygen-mediated mechanism (LOM), the oxide path mechanism (OPM), the coupled oxygen evolution mechanism (COM), and the emerging valence oscillation mechanism. Subsequently, it discusses the fundamental structure, synthesis methods, and characterization techniques of Ni-LDH. Then it summarizes six design strategies for Ni-LDH and discusses the structural optimization and OER performance of undoped and doped (metal/non-metal) Ni-LDH systems. Finally, it analyzes the key industrial application challenges of Ni-LDH electrocatalysts and outlines promising directions for future research, aiming to offer guidance for the rational design of high-performance Ni-LDH OER electrocatalysts.