Ferrocene Formic Acid Surface Modified Ni(OH)2 for Highly Efficient Alkaline Oxygen Evolution

Abstract

FeNi-based hybrid materials are among the most representative catalysts for alkaline oxygen evolution reaction (OER), but the modulation of their surface atoms to achieve the optimal catalytic properties is still a big challenge. Here, we report the surface modification of Ni(OH)2/nickel foam (NF)-based electrocatalyst with a trace amount of ferrocene formic acid (FFA) (FFA-Ni(OH)2/NF) for highly efficient OER. Owing to the strong electron interaction and synergistic effects of Fe-Ni heteroatoms, FFA-Ni(OH)2/NF exhibits an overpotential of 311 mV at a current density of 100 mA cm−2. Impressively, the overpotential of FFA-Ni(OH)2/NF at 100 mA cm−2 is 108 mV less than that of bulk phase doped Ni/FFA(OH)2/NF, demonstrating the surprising effect of heteroatomic surface modification. In addition, by introducing a small amount of surface modifier into the electrolyte, the weak surface reconstruction process in the electrochemical process can be fully utilized to achieve obvious modification effects. Therefore, this work fully proves the feasibility of improving catalytic activities of FeNi-based catalysts by modifying surface heterogeneous atom pairs.