Fig. 1: Studied monolayer titania.
From: High proton conductivity through angstrom-porous titania
a Schematics of single-Ti-atom vacancies in monolayer titania. Left: top view with the shown lattice parameters; right: tilted 3D view. The blue and red balls denote Ti and O atoms, respectively. The green balls highlight vacancy positions. b AFM of a titania sheet placed on an oxidized silicon wafer. Scale bar, 10 µm. Yellow profile, height-trace along the yellow solid line indicating the titania thickness. Inset: same crystal after being transferred over a 3 μm diameter aperture etched in a silicon-nitride substrate. c HRTEM image of a titania monolayer. Scale bar, 1 nm. Dark spots are Ti atoms. They form an orthorhombic lattice that is often interrupted by brighter blurred rectangles, two of which are indicated by circles.
