CuO@CoFe Layered Double Hydroxide Core–Shell Heterostructure as an Efficient Water Oxidation Electrocatalyst under Mild Alkaline Conditions

Designing hierarchical electrocatalysts with superior water oxidation performance is highly desirable for the production of renewable chemical fuels. Here, we report the development of a CuO@CoFe layered double hydroxide core–shell heterostructure supported on Cu foil (CuO@CoFe-LDH/CF) as a highly active catalyst electrode for water oxidation under mild alkaline conditions. In a 0.2 M carbonate buffer solution (pH 11), it only needs a small overpotential of 213 mV to achieve 10 mA cm^–2, outperforming all reported electrocatalysts at comparable testing conditions. It also shows outstanding long-term durability.