Sequentially Electrodeposited Fe6Ni/FeNi6 NiFe Hydroxide/LDH-Like Double-Layer Electrode for Efficient Oxygen Evolution Reaction

Abstract

In this work, we prepared a sequentially electrodeposited NiFe hydroxide/LDH-like double-layer electrode on nickel foam by using precursor solutions with different Fe/Ni feed ratios in two deposition steps. The resulting sample, denoted as Fe6Ni@FeNi6 for convenience, exhibited superior OER performance compared with the single-step deposited controls. Specifically, the Fe6Ni@FeNi6-labeled sample required overpotentials of 249 and 264 mV to deliver current densities of 20 and 50 mA cm−2, respectively, together with a Tafel slope of 41.4 mV dec−1. The catalyst also showed good stability under the present testing conditions. Overall, this work provides a simple and effective strategy for tuning NiFe hydroxide-based OER electrodes through sequential electrodeposition.