Chemically Deposited Amorphous Zn-Doped NiFeO _xH _y for Enhanced Water Oxidation

Although NiFeO_xH_y 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 NiFeO_xH_y (Zn;NiFeO_xH_y) that has advanced electrocatalytic activity and stability in comparison to pure NiFeO_xH_y in the OER via simple chemical bath deposition and electrochemical activation. The improvement with Zn;NiFeO_xH_y 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 NiFeO_xH_y-based electrocatalysts and improves our understanding of redox tuning through inductive effects, thereby leading to advanced OER catalyst developments.