Tuning Surface Electronic Configuration of NiFe LDHs Nanosheets by Introducing Cation Vacancies (Fe or Ni) as Highly Efficient Electrocatalysts for Oxygen Evolution Reaction

Abstract

Intrinsically inferior electrocatalytic activity of NiFe layered double hydroxides (LDHs) nanosheets is considered as a limiting factor to inhibit the electrocatalytic properties for oxygen evolution reaction (OER). Proper defect engineering to tune the surface electronic configuration of electrocatalysts may significantly improve the intrinsic activity. In this work, the selective formation of cation vacancies in NiFe LDHs nanosheets is successfully realized. The as-synthesized NiFe LDHs-V and NiFe LDHs-V electrocatalysts show excellent activity for OER, mainly attributed to the introduction of rich iron or nickel vacancies in NiFe LDHs nanosheets, which efficiently tune the surface electronic structure increasing the adsorbing capacity of OER intermediates. Density functional theory (DFT) computational results also further indicate that the OER catalytic performance of NiFe LDHs can be pronouncedly improved by introducing Fe or Ni vacancies.

Tuning Surface Electronic Structure of Two‐Dimensional Cobalt‐Based Hydroxide Nanosheets for Highly Efficient Water Oxidation

“…Generally, tuning electronic structure of catalyst has proven to be an effective way to further enhance the OER performance through inducing oxygen and/or metal vacancies. [6,7] To decrease the free energy absorption of the OER intermediates (OH*, O*, and OOH*) and facilitate final product desorption is achievable for improving the overall OER performances. [8] Yanyong Wang et al reported that the NiFe LDHs-V Fe and NiFe LDHs-V Ni electrocatalysts with rich iron or nickel vacancies can show excellent OER activity, which is attributed to efficiently tuning surface electronic structure and increasing the adsorbing capacity of OER intermediates.…”

Design of Multi‐Metallic‐Based Electrocatalysts for Enhanced Water Oxidation

“…The generated defects on the surface or in the lattice generally provide more active sites and significantly improve the electrochemical surface area (ECSA). For instance, Zn and Al templates were introduced to LDH nanosheet structures and then partially etched to form abundant pores on LDH nanosheets and to generate rich active sites . Liu and co‐workers replaced CO 3 2− anions with COOH − in the intercalation of CoFe LDH to achieve defective CoFe composites with enhanced OER activity .…”

A Composite Bifunctional Oxygen Electrocatalyst for High‐Performance Rechargeable Zinc–Air Batteries

“…[1] Rechargeable batteries are considered av ital approach fors ustainable energy storage and conversion to meet the increasing requirements of consumer electronics, electric vehicles,a nd the related energy industry. [2] Amongt he various battery configurations, rechargeable zinc-airb atteries demonstrate great potentiala sn ext-generation energy storaged evices because of their ultrahight heoreticale nergyd ensity of 1086Whkg À1 (including oxygen), [3][4][5][6] inherents afety originating from the use of aqueous electrolyte, [7] and additional advantages including low cost, [8] naturala bundance, [9] ande nvironmental benignity. [10] Therefore, developingh igh-performancer echargeable zinc-airbatteries has received extensive attention worldwide.…”