Electrocatalytic water oxidation on CuO–Cu₂O modulated cobalt-manganese layered double hydroxide

Abstract

Layered double hydroxides (LDH) are potential electrocatalysts to address the sluggish oxygen evolution reaction (OER) of water splitting. In this work, copper oxide (CuO/Cu₂O) nanoparticles are integrated with cobalt-manganese layered double hydroxide (CoMn-LDH) to enhance their performance towards OER. The catalyst is synthesized by growing CoMn-LDH nanosheets in the presence of CuO/Cu₂O nanoparticles that were obtained by the calcination of the copper containing metal-organic framework (HKUST-1). The synthesized CoMn-LDH@CuO/Cu₂O electrocatalyst shows excellent activity towards OER with an overpotential of 297 mV at a catalytic current density of 10 mA cm^-2 and have a Tafel slope value of 89 mV dec^-1. Moreover, a slight decrease in the performance parameters is observed until the 15 h of continuous operation. We propose that the conductive strength of CuO/Cu₂O and its synergistic effect with the CoMn-LDH are responsible for the improved OER performance of the desired electrocatalyst.