Cu3P/CuO Core‐Shell Nanorod Arrays as High‐Performance Electrocatalysts for Water Oxidation

Abstract Earth‐abundant transition‐metal‐based oxides are potential candidates to replace the state‐of‐the‐art noble‐metal‐based oxygen evolution catalysts (OECs) such as IrO 2 and RuO 2 . Despite the low cost and large abundance, copper‐based OER catalysts have been less frequently studied, mainly owing to the low electrical conductivity of copper oxides that results in large overpotential and sluggish kinetics for oxygen evolution. We report here the in situ fabrication of semi‐metallic Cu 3 P nanorod arrays on commercial copper foam via a template approach; the resulting self‐supported core‐shell Cu−Cu 3 P/CuO electrode has the merits of high electrical conductivity, large active area, and short diffusion paths for electrolyte and evolved oxygen, exhibiting a low overpotential of 315 mV and high durability over 50 h at a current density of 10 mA cm −2 for OER in 1.0 M KOH. The remarkable OER performance reported here is not only superior to that of analogous Cu−CuO foam electrode, but also outperforms those of copper‐based OER electrocatalysts in the literature.