Optimization of NiFe oxygen evolution reaction catalytic electrode based on characterization of onset potential distribution

Lower onset potential and uniform distribution of catalytic performance are crucial for catalytic electrodes. This study presents a method for characterizing the spatial distribution of the initial potential on the surface of the oxygen evolution reaction (OER) catalytic electrode using total internal reflection imaging (TIRi). By applying linear sweep voltammetry (LSV) with incremental positive potential to the electrode, the surface of the electrode generates micro-to-nanometer-sized O2 bubbles during the initial phase of OER, resulting in an increase in light intensity and a decrease in the effective refractive index (RI). By establishing the relationship between light intensity and potential, the spatial distribution of the OER onset potential can be quantified, enabling direct visualization of the electrode's surface and its catalytic activity. Furthermore, we applied the TIRi method to assess the influence of different substrates and electrodeposition conditions on the catalytic activity, repeat-ability, and durability of NiFe catalytic electrodes. This research contributes to the evaluation of various elec-trode deposition methods for large-scale catalytic electrodes and the rational manufacturing of efficient OER electrodes in industrial energy devices, promoting the development of the hydrogen energy field.