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

Y.-H. Lu, C. Morales, X. Zhao, M. A. van Spronsen, A. Baskin, D. Prendergast, P. Yang, H. A. Bechtel, E. S. Barnard, D. Frank Ogletree, V. Altoe, L. Soriano, A. M. Schwartzberg and M. Salmeron

Nano Letters 20, 6364 (2020)
Free-standing ultrathin (∼2 nm) films of several oxides (Al2O3,TiO2, and others) have been developed, which are mechanically robust and transparent to electrons with Ekin ≥ 200 eV and to photons. We demonstrate their applicability in environmental X-ray photoelectron and infrared spectroscopy for molecular level studies of solid–gas (≥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.