Cu(OH)₂@CoCO₃(OH)₂·nH₂O Core–Shell Heterostructure Nanowire Array: An Efficient 3D Anodic Catalyst for Oxygen Evolution and Methanol Electrooxidation

A Cu(OH)2@CoCO3(OH)2·nH2O (CCHH) core–shell heterostructure nanowire array acts as robust 3D oxygen evolution reaction catalyst. It needs an overpotential of 270 mV to drive 50 mA cm−2 in 1.0 m KOH, outperforming CCHH nanowire arrays on copper foam and most reported Co-based oxygen evolution reaction catalysts in alkaline media. It is also efficient for methanol electrooxidation.