Modulating interfacial electronic structure of CoNi LDH nanosheets with Ti3C2Tx MXene for enhancing water oxidation catalysis

Abstract

Developing efficient nonprecious metal electrocatalysts is urgently needed to promote the sluggish kinetics of oxygen evolution reaction (OER). Transition metals-based layered double hydroxides (LDH) have been considered as highly active OER catalysts, while low conductivity and limited active site exposures hinder their further applications. Herein, CoNi LDH/Ti3C2Tx MXene is facilely constructed by using Ti3C2Tx coated nickel foam as support to load CoNi LDH through electrodeposition. Surprisingly, a significant enhancement in OER activity of pristine CoNi LDH is achieved due to the metallic conductivity and hydrophilic and electronegative surface of Ti3C2Tx. Importantly, CoNi LDH/Ti3C2Tx displays prominent OER performance and stability in alkaline medium, which exhibits a low overpotential of 257.4 mV to reach current density of 100 mA/cm2 and a small Tafel slope of 68 mV/dec. The experimental and calculated results demonstrate electron transfer from CoNi LDH to Ti3C2Tx plays a significant role in boosting OER activity by lowering the binding strength of intermediates.