Co-Doped CuO Nanoarray: An Efficient Oxygen Evolution Reaction Electrocatalyst with Enhanced Activity

It is highly desired to enhance the catalytic activity of oxygen evolution reaction (OER) electrocatalysts made of earth abundant elements. In this Letter, we report that the OER activity of a CuO nanoarray can be largely enhanced by Co doping. In 1.0 M KOH, the Co-CuO nanoarray on copper foam requires a current densities of 50 and 100 mA cm(-2) at overpotentials of only 299 and 330 mV, respectively. It also shows superior long-term durability over 15 h with a turnover frequency of 0.056 mol O-2 s(-1) at an overpotential of 300 mV.