Optimizing Gas Desorption and Mass Transfer Kinetics of OER Electrodes via Patterned Engineering

Abstract

Efficient and stable water electrolysis electrodes are of great significance for sustainable energy conversion. However, conventional catalysts still suffer from bottlenecks such as insufficient utilization of active sites and mass transfer limitations caused by bubble blockage. In this work, a synergistic optimization strategy is proposed by integrating a high-performance NiFe layered double hydroxide (NiFe-LDH) catalyst with controllable patterned structures. Through a brush-plating technique, localized deposition and stripe-patterned construction of the catalyst were achieved on a metallic substrate. The resulting electrode exhibits good crystallinity, uniform elemental distribution, and super-aerophobic interfacial properties. In 1 M KOH, the patterned NiFe-LDH electrode delivers a low overpotential of approximately 210 mV at 10 mA cm⁻² for the oxygen evolution reaction (OER) and maintains an extremely low degradation rate of 26.69 μV h⁻¹ over more than 1000 h of continuous operation, significantly outperforming commercial Raney nickel and noble-metal RuO₂ catalysts. By further tuning the dimensions of the striped structure, directional migration of gas bubbles between “catalyst–blank” regions was realized, forming effective “bubble pathways” that markedly enhance bubble mass transfer and restore the intrinsic catalytic activity. High-speed imaging combined with bubble contact angle analysis reveals the underlying mechanism by which patterned structures regulate bubble detachment kinetics. Overall, this study highlights the critical role of efficient bubble mass transfer in water electrolysis systems and provides a cost-effective, scalable interfacial patterning strategy for electrode design, offering new insights into the structural engineering of future electrochemical energy conversion devices.