ZnO powders as multi-facet single crystals

Francia Haque (1, 2, 3) , Stéphane Chenot (4, 2, 3) , Francesc Viñes (5) , Francesc Illas (5) , Slavica Stankic (6, 2, 3) , Jacques Jupille (6, 2)

1 INSP - Institut des Nanosciences de Paris
2 INSP-E9 - Oxydes en basses dimensions
3 INSP - Institut des Nanosciences de Paris
4 INSP-E8 - Croissance et propriétés de systèmes hybrides en couches minces
5 UB - Universitat de Barcelona
6 INSP-E9 - Oxydes en basses dimensions

Oxides are most commonly found in divided forms with properties difficult to control since their crystallographic orientations usually escape analysis. To overcome this an appropriate model system can be provided by ZnO smoke which, obtained by combustion of Zn in air, exhibits nanoparticles with well-defined surface facets. The present work focuses on the interaction of water with ZnO smokes by combining density functional theory based simulations and infrared spectroscopy measurements with applied pressures from 10 À7 to 1 mbar. We demonstrate that the use of ultra-high vacuum allows the analysis of the very first stages of the adsorption, and report on water structures on ZnO(11 % 20) for the first time. We further show that ZnO powders behave as multi-facet single crystals involving (10 % 10), (11 % 20), (0001), and (000 % 1) surfaces with the polar orientations corresponding to 25% of the total surface area. A great deal of cross-agreements between experimental results and simulation provides a simple approach for the examination of hydroxylated/hydrated ZnO smokes and can be widely applied on other ZnO-related powders.

Domaines: Chimie théorique et/ou physique; Chimie-Physique [physics.chem-ph]

Francia Haque, Stéphane Chenot, Francesc Viñes, Francesc Illas, Slavica Stankic, et al.. ZnO powders as multi-facet single crystals. Physical Chemistry Chemical Physics, 2017, 605, pp.10622-10628. ⟨10.1039/C7CP01635B⟩. ⟨hal-01518347⟩