Ultracompact Electrical Double Layers at TiO(110) Electrified Interfaces.

Metal-oxide aqueous interfaces are important in areas as varied as photocatalysis and mineral reforming. Crucial to the chemistry at these interfaces is the structure of the electrical double layer formed when anions or cations compensate for the charge arising from adsorbed H or OH. This has proven extremely challenging to determine at the atomic level.

Transition from monolayer-thick 2D to 3D nano-clusters on α-AlO(0001).

This paper reports on the long-standing puzzle of the atomic structure of the Ag/α-AlO(0001) interface by combining X-ray absorption spectroscopy, to determine Ag local environment [ average Ag-Ag () and Ag-O () interatomic distances and Ag coordination numbers (CN)], and numerical simulations on nanometric-sized particles. The experimental key was the capability of a structural study of clusters involving only a few atoms. The concomitant decrease of and CN with decreasing cluster size provides unambiguous fingerprints for the dimensionality of the Ag clusters in the subnanometric regime leading to a series of unexpected results regarding the size-dependent interface structures.

Core level shifts as indicators of Cr chemistry on hydroxylated α-AlO(0001): a combined photoemission and first-principles study.

The Cr/α-AlO(0001) interface has been explored by X-ray photoemission spectroscopy, X-ray absorption spectroscopy (XAS) and first-principles calculations of core level shifts including final state effects. After an initial oxidation a reaction with residual surface OH but no reduction of the alumina substrate, Cr grows in a metallic form without any chemical effect on the initially oxidized Cr. However, Cr metal lacks crystallinity.

Water-Induced Reversal of the TiO(011)-(2 × 1) Surface Reconstruction: Observed with in Situ Surface X-ray Diffraction.

The (011) termination of rutile TiO is reported to be particularly effective for photocatalysis. Here, the structure of the interface formed between this substrate and water is revealed using surface X-ray diffraction. While the TiO(011) surface exhibits a (2 × 1) reconstruction in ultra-high vacuum (UHV), this is lifted in the presence of a multilayer of water at room temperature.

Structure of a Superhydrophilic Surface: Wet Chemically Prepared Rutile-TiO(110)(1 × 1).

Surface X-ray diffraction has been employed to quantitatively determine the geometric structure of an X-ray-induced superhydrophilic rutile-TiO(110)(1 × 1) surface. A scatterer, assumed to be oxygen, is found at a distance of 1.90 ± 0.