Altering electronic structure of nickel foam supported CoNi-based oxide through Al ions modulation for efficient oxygen evolution reaction.

Developing highly active and durable non-precious metal-based electrocatalysts for the oxygen evolution reaction (OER) is crucial in achieving efficient energy conversion. Herein, we reported a CoNiAl _0.5 O/NF nanofilament that exhibits higher OER activity than previously reported IrO ₂ -based catalysts in alkaline solution. The as-synthesized CoNiAl _0.5 O/NF catalyst demonstrates a low overpotential of 230 mV at a current density of 100 mA cm ^-2 , indicating its high catalytic efficiency. Furthermore, the catalyst exhibits a Tafel slope of 26 mV dec ^-1 , suggesting favorable reaction kinetics. The CoNiAl _0.5 O/NF catalyst exhibits impressive stability, ensuring its potential for practical applications. Detailed characterizations reveal that the enhanced activity of CoNiAl _0.5 O/NF can be attributed to the electronic modulation achieved through Al ³⁺ incorporation, which promotes the emergence of higher-valence Ni metal, facilitating nanofilament formation and improving mass transport and charge transfer processes. The synergistic effect between nanofilaments and porous nickel foam (NF) substrate significantly enhances the electrical conductivity of this catalyst material. This study highlights the significance of electronic structures for improving the activity of cost-effective and non-precious metal-based electrocatalysts for the OER.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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