Ultrathin Free-Standing Oxide Membranes for Electron and Photon Spectroscopy Studies of Solid-Gas and Solid-Liquid Interfaces

Free-standing ultrathin (similar to 2 nm) films of several oxides (Al2O3,TiO2, and others) have been developed, which are mechanically robust and transparent to electrons with E-kin >= 200 eV and to photons. We demonstrate their applicability in environmental X-ray photoelectron and infrared spectroscopy for molecular level studies of solidgas (>= 1 bar) and solid-liquid interfaces. These films act as membranes closing a reaction cell and as substrates and electrodes for electrochemical reactions. The remarkable properties of such ultrathin oxides membranes enable atomic/molecular level studies of interfacial phenomena, such as corrosion, catalysis, electrochemical reactions, energy storage, geochemistry, and biology, in a broad range of environmental conditions.