Free-Standing Porous Cu-Based Nanowires as Robust Electrocatalyst for Alkaline Oxygen Evolution Reaction

Cu-based catalysts have emerged as important candidates for oxygen evolution reaction (OER) electrocatalysts. Based on Mg72Cu28 alloy ribbon, a free-standing porous Cu hydroxide/oxide nanowires (p-CuNWs) was fabricated by a combined method of chemical dealloying and electrochemical treatment. The structure and chemical state of p-CuNWs were characterized by X-ray diffraction pattern analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy. The p-CuNWs were identified as mixed Cu(OH)2 and CuO with a high active surface area, which exhibit robust activity for OER in alkaline solution with an overpotential of only 377 mV to offer current density of 50 mA cm−2, small Tafel slope of 85 mV dec−1. The catalytic durability of p-CuNWs was also evaluated by cyclic voltammetry cycles and a small decay of activity was observed.