Interfacial charge transfer modulation in laser-synthesized catalysts for efficient oxygen evolution†

Abstract

Advancements in laser-based material development have enabled precise engineering of catalysts, thus promoting efficient and sustainable water-splitting reactions. This study presents a green approach for synthesizing a layered double hydroxide (LDH)-based catalyst on nickel foam (NF) using pulse-laser irradiation in liquids and microwave processes. The enhanced catalytic efficiency of NiFe-based LDH compared to IrO₂/NF is demonstrated by its low overpotential (η ∼ 292 mV), high current density, and enhanced charge transfer kinetics. Density functional theory calculations reveal the tailoring phenomenon of Fe on the material's electronic structure, significantly enhancing its performance in the oxygen evolution reaction (OER). Spin-polarized electrons contribute to spin-aligned oxygen generation via quantum spin–exchange interactions, accelerating the OER kinetics. Electrochemical and analytical techniques demonstrated that the surface of the NiFe LDH/Ni(OH)₂/NF transforms into high-valent Ni/FeOOH active species, optimizing the adsorption energy of *OH intermediates during OER. Furthermore, this study investigates the effective tuning of Fe incorporation on the structural, electronic, and catalytic properties of Ni(OH)₂ and NiFe LDHs, demonstrating a change in the band gap (from 1.77 eV to 1.81 eV) and an increase in the intrinsic magnetic moment (from 8 μ_B to 20.3 μ_B). Additionally, catalytic assessments revealed superior OER performance, a reduction in η, and a 57% improvement in efficiency for NiFe LDH, consistent with experimental findings and confirming the enhanced catalytic effects of NiFe LDH/Ni(OH)₂/NF in OER. These results highlight the promising potential of laser-mediated techniques in fabricating efficient and cost-effective OER catalysts for sustainable energy production.