Rapid synthesis of ultralong Fe(OH) 3 :Cu(OH) 2 core-shell nanowires self-supported on copper foam as a highly efficient 3D electrode for water oxidation.

One-dimensional core-shell nanowire materials have recently received great attention as durable catalysts for water splitting. Herein we report the facile and rapid synthesis of ultralong Fe(OH)3 :Cu(OH)2 core-shell nanowires grown in situ on an open 3D electrode to function as a highly efficient electrocatalyst for water oxidation. It only requires an overpotential of ∼365 mV to reach a 10 mA cm-2 current density in 1.0 M KOH. As far as we know, this shows the best result amongst Cu-based heterogeneous OER systems reported to date.