Ethanol-mediated electrochemical reconstruction for efficient catalysts for oxygen evolution reaction

Developing efficient and durable oxygen evolution reaction (OER) catalysts is of great significance for achieving industrial-scale production of green hydrogen. This study proposes an innovative ethanol-mediated electrochemical surface reconstruction strategy to significantly enhance the OER activity of nickel-based catalysts. This strategy effectively promotes the transformation of Ni(OH)₂ into the highly active γ-NiOOH phase, which greatly increases the density of surface Ni³⁺ active sites and optimizes the catalyst's microstructure and electronic properties. After electrochemical reconstruction, the Ni(OH)₂-R exhibits outstanding catalytic activity, requiring an overpotential of only 270 mV at 100 mA cm^-2. This represents a substantial reduction of 155 mV compared to the untreated sample. This strategy is also successfully applied to Mo-doped Ni(OH)₂ and commercial nickel mesh (NiAl-NM). Furthermore, the catalyst activity can be regenerated through simple electrolyte replacement and short-term reconstruction treatment after long-term operation, thereby extending catalyst's service life. This work presents promising prospects for industrial applications due to its simple process, low cost, and capability for in situ activity regeneration, which holds significant implications for advancing water electrolysis hydrogen production technology.