Average metal ion electronegativity as a general descriptor for screening Ni-based double hydroxides with high electrocatalytic water oxidation activity

Due to the multiclass complex processes in the oxygen evolution reaction (OER) by Ni-based double hydroxides (DHs) electrocatalysts, it is necessary to seek a comprehensive assessment to uncover the electrochemical nat-ure. Here, Ni0.8M0.2 DHs and Ni0.7M0.3 DHs nanowires (M = Zn, Co, Fe, Cu) were prepared by a hydrothermal method. As the intrinsic chemical property, metal ion electronegativity (MIE) as the descriptor, the struc-ture-activity relationship between MIE and OER reaction intermediates' adsorption and desorption capacity was researched by the electrochemical impedance analysis. At the top of the volcano trend (MIE = 1.39, Ni0.8Co0.2 DHs), it is screened and exhibits the lowest interfacial charge transfer resistance and the adsorption and desorption resistance of intermediates. This work provides a cost-effective method based on the theory of electronegativity equilibrium for the precise screening and design of high-active OER electrocatalysts.