BaTiO 3 -driven kinetic enhancement in NiCuMn-LDH for advanced oxygen evolution catalysis

Abstract

Developing efficient and stable electrocatalysts for the oxygen evolution reaction (OER) is crucial for advancing water splitting technology. While layered double hydroxides (LDHs) are promising non-precious materials, they are often limited by modest conductivity and active site accessibility. To address this, we synthesize a novel hybrid electrocatalyst by combining a ternary nickel-copper-manganese LDH (NiCuMn-LDH) with ferroelectric barium titanate (BaTiO 3 ) nanorods. The prepared composite was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The synergistic interplay between the multimetal LDH, which provides highly active sites and rich redox chemistry, and the polarized BaTiO 3 , which enhances charge transfer via its internal electric field, results in high OER performance. The NiCuMn-LDH@BaTiO 3 composite exhibited a low overpotential of 305 mV at 50 mA cm -2 and a small Tafel slope of 40.9 mV dec -1 in 1.0 M KOH, outperforming both the pristine LDH and a benchmark RuO 2 catalyst. Furthermore, it exhibited good long-term stability for 96 h at a high current density of 250 mA cm -2 with minimal degradation. This work highlighted the potential of ferroelectric-enhanced electrocatalysis to overcome the activity-stability-conductivity trade-off, presenting a highly viable earth-abundant anode for industrial water electrolysis.