Chemically Deposited Amorphous Zn-Doped NiFeOxHy for Enhanced Water Oxidation

Although NiFeOxHy has attracted enormous attention as an alkaline water electrolyzer owing to its high performance in the oxygen evolution reaction (OER), it still requires further improvement in terms of catalytic activity, durability, and an underlying understanding of the mechanism. Here we report the fabrication of Zn-doped NiFeOxHy (Zn;NiFeOxHy) that has advanced electrocatalytic activity and stability in comparison to pure NiFeOxHy in the OER via simple chemical bath deposition and electrochemical activation. The improvement with Zn;NiFeOxHy is due to the Zn2+ dopant, a strong Lewis acid that modulates its electronic property for better intermediate binding for the electrochemical process, resulting in the stabilization of the OER-active phase. This work opens up an opportunity to elucidate the detailed mechanism of NiFeOxHy-based electrocatalysts and improves our understanding of redox tuning through inductive effects, thereby leading to advanced OER catalyst developments.