Noble Metal-Free Copper Hydroxide as an Active and Robust Electrocatalyst for Water Oxidation at Weakly Basic pH

Copper hydroxide (Cu(OH)(2)) is a quite inexpensive and abundant material, but the literature contains no reports of using it as a stable water oxidation catalyst (WOC). In this study, we report for the first time that Cu(OH)(2) material synthesized from a simple copper salt can be used as a WOC with good activity and stability. Under optimal conditions using Cu(OH)(2) as the electrocatalyst, a catalytic current density of 0.1 mA/cm(2) can be achieved under an applied potential of similar to 1.05 V relative to Ag/AgCl at pH 9.2. The slope of the Tafel plot is 78 mV/dec. The Tafel plot indicates that a current density of similar to 0.1 mA/cm(2) requires an overpotential of 550 mV. The Faradaic efficiency was measured to be similar to 95%. The as-synthesized Cu(OH)(2) material was characterized by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy.