Interfacial Interaction between FeOOH and Ni–Fe LDH to Modulate the Local Electronic Structure for Enhanced OER Electrocatalysis

Abstract

Toward the pursuit of high-performance Ni2+/Co2+/Fe3+-relevant oxygen evolution reaction (OER) electrocatalysts, the modulation of local electronic structure of the active metal sites provides the fundamental motif, which could be achieved either through direct modifications of local chemical environment or interfacial interaction with a second metal substrate which possesses high electronegativity (typically noble metal Au). Herein, we report that the local electronic structure of Ni–Fe layered double hydroxide (LDH) could be favorably modulated through strong interfacial interactions with FeOOH nanoparticles (NPs). The biphasic and multiscale composites FeOOH/LDH demonstrated an increasingly pronounced synergy effect for OER catalysis when the average size of FeOOH NPs decreases from 18.0 to 2.0 nm. Particularly, the composite with average size of FeOOH NPs of 2.0 nm exhibited an overpotential of 174 mV at 10 mA cm–2 and a tafel slope of 27 mV dec–1 in 1.0 M KOH, outmatching all the noble and non-noble ...