Interface engineering of porous Co(OH)2/La(OH)3@Cu nanowire heterostructures for high efficiency hydrogen evolution and overall water splitting

Abstract

Transition metal hydroxide heterostructures have exhibited great potential to substitute precious metal catalysts for electrocatalytic water splitting due to their tunable electronic structures and boosted catalytic performance. However, exploring heterostructure catalysts composed of transition metal hydroxides and rare earth hydroxides with excellent catalytic behavior and durability still remains a great challenge. Herein, the porous cobalt hydroxide and lanthanum hydroxide heterostructure is constructed on copper nanowires (Co(OH)₂/La(OH)₃@Cu NWs, denoted as CH/LH@Cu NWs in the text). Benefitting from the two dimensional morphology, pore-rich feature and substantial heterointerfaces of CH/LH as well as the hierarchical Cu NW substrate, the CH/LH@Cu NW catalyst shows outstanding hydrogen evolution reaction (HER) activities with an ultralow overpotential of 36 mV at 10 mA cm⁻², together with excellent alkaline oxygen evolution reaction (OER) performance with an overpotential of 273 mV at 100 mA cm⁻². Using the CH/LH@Cu NW catalyst as the anode and cathode, the electrolytic cell requires only 1.56 V to attain the current density of 20 mA cm⁻² together with a preferable long-term stability. This work offers new understanding into the development of high-efficiency water splitting electrocatalysts via heterostructural and interfacial strategies.