Berlin 2018 – scientific programme

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O: Fachverband Oberflächenphysik

O 45: Poster: Solid-Liquid Interfaces - Structure, Spectroscopy, Reactions and Electrochemistry

O 45.20: Poster

Tuesday, March 13, 2018, 18:15–20:30, Poster A

Wetting properties of CuFeO2 delafossite for photo-catalytic processes — Diego Diaz, Robert Wheatley, Martín Roble, Marcelo Cisternas, Donovan Diaz, •Ulrich G. Volkmann, Alejandro Cabrera, Birger Seifert, and Sascha Wallentowitz — Institute of Physics and CIEN-UC, P. Univ. Catolica de Chile, Santiago, Chile

Metal oxides and ceramics are used universally as catalytic and photo-catalytic materials for a very wide range of chemical reaction processes. For water based reactions, hydroxylization, a process dependent upon the wettability of at the surface, can greatly influence catalytic activity of a metal oxide. In this work we present an investigation of the wetting properties CuFeO2 delafossite oxide synthesized using hydrothermal methods. We show how the "as grown" powder produces a strong hydrophobic effect which is described using the Cassie model for suspended droplets upon a rough surface comprised of two materials. Treatment of the powder via milling, pelletization and sintering reveals a hydrophobic surface which is then described by the Wenzel regime. However, in some cases we observe a rapid absorption of the water which we currently attribute to micro-capillaries present in the pellet sample. The material and its surface is characterized via XRD, AFM, FESEM and EDS methods. Acknowledgements: CONICYT Fellowships (MR, MC) and CONICYT-PIA ACT 1409.