Ultrathin Amorphous Silica Membrane Enhances Proton Transfer across Solid‐to‐Solid Interfaces of Stacked Metal Oxide Nanolayers While Blocking Oxygen

A large jump of proton transfer rates across solid-to-solid interfaces by inserting an ultrathin amorphous silica layer into stacked metal oxide nanolayers is discovered using electrochemical impedance spectroscopy and FT-IRRAS. The triple stacked nanolayers of Co3O4, SiO2, and TiO2 prepared by atomic layer deposition (ALD) enable a proton flux of 2,400 + 60 s -1 nm -2 (pH 4, room temperature), while a single TiO2 (5 nm) layer exhibits a 3-fold lower flux of 830 s -1 nm -2 .