Improved water oxidation with metal oxide catalysts via a regenerable and redox-inactive ZnOxHy overlayer

Abstract

We report a regenerable and redox-inactive ZnO_xH_y layer that was in situ deposited onto metal oxides MO_z (M = Co, Fe, and Ni) in alkaline media containing [Zn(OH)₄]²⁻ species during water oxidation. An interface dipole was developed at the MO_z/Zn interface, resulting in a decrease of the OER overpotential. Exemplified by the CoO_z/ZnO_xH_y bilayer structure, it presented a 155 mV lower overpotential to deliver 10 mA cm⁻² and long-term stability relative to the unmodified CoO_z film.