The Fate of the Formic Acid Proton on the Anatase TiO(101) Surface.

As a prototype adsorption reaction of gas Brønsted acid on oxides, we study the adsorption of formic acid on anatase. We perform infrared spectroscopy measurements of adsorbed HCOOH and HCOOD on TiO nanopowders, from 13 K up to room temperature in an ultra-high vacuum chamber. We assign the IR signals via computed spectra from nuclear quantum dynamics simulations using our divide-and-conquer semiclassical ab initio molecular dynamics method.

Telecom single-photon emitters in GaN operating at room temperature: embedment into bullseye antennas.

The ideal single-photon source displaying high brightness and purity, emission on-demand, mature integration, practical communication wavelength (i.e., in the telecom range), and operating at room temperature does not exist yet.

Influence of Unsaturations on the Organization and Air Reactivity of Triglyceride Monolayers.

The behavior of Langmuir monolayers of saturated and unsaturated C18 triglycerides (TAGs) was studied as two-dimensional (2D) models for paint systems at the air-water interface or transferred onto solid films. The organization of saturated tristearin (C18:0) monolayer was probed thanks to grazing incidence X-ray diffraction: one observes a hexagonal packing of the chains perpendicular to the air-water interface, in contrast to what is described in the literature. Conversely, the mono- and polyunsaturated TAGs (triolein C18:1, trilinolein C18:2, and trilinolenin C18:3) monolayers do not present any organization at the air-water interface but do exhibit peculiar reactivity regarding the air atmosphere.

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.

Broadband decoupling of intensity and polarization with vectorial Fourier metasurfaces.

Intensity and polarization are two fundamental components of light. Independent control of them is of tremendous interest in many applications. In this paper, we propose a general vectorial encryption method, which enables arbitrary far-field light distribution with the local polarization, including orientations and ellipticities, decoupling intensity from polarization across a broad bandwidth using geometric phase metasurfaces.