Cryoaerogels and Cryohydrogels as Efficient Electrocatalysts

verfasst von: Dennis Müller, Dániel Zámbó, Dirk Dorfs, Nadja C. Bigall
Abstract: Additive-free cryoaerogel coatings from noble metal nanoparticles are prepared and electrochemically investigated. By using liquid nitrogen or isopentane as cooling medium, two different superstructures are created for each type of noble metal nanoparticle. These materials (made from the same amount of particles) have superior morphological and catalytic properties as compared to simply immobilized, densely packed nanoparticles. The morphology of all materials is investigated with scanning electron microscopy (SEM). Electrochemically active surface areas (ECSAs) are calculated from cyclic voltammetry measurements. The catalytic activity is studied for the ethanol oxidation reaction (EOR). Both are found to be increased for superstructured materials prepared by cryoaerogelation. Furthermore, cryoaerogels with cellular to dendritic structure that arise from freezing with isopentane show the best catalytic performance and highest ECSA. Moreover, as a new class of materials, cryohydrogels are created for the first time by thawing flash-frozen nanoparticle solutions. Structure and morphology of these materials match with the corresponding types of cryoaerogels and are confirmed via SEM. Even the catalytic activity in EOR is in accordance with the results from cryoaerogel coatings. As a proof of concept, this approach offers a novel platform towards the easier and faster production of cryogelated materials for wet-chemical applications.
Organisationseinheit(en): Institut für Physikalische Chemie und Elektrochemie
Laboratorium für Nano- und Quantenengineering
PhoenixD: Simulation, Fabrikation und Anwendung optischer Systeme
Typ: Artikel
Journal: SMALL
Band: 17
ISSN: 1613-6810
Publikationsdatum: 06.05.2021
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Biotechnologie, Biomaterialien, Chemie (insg.), Werkstoffwissenschaften (insg.)
Elektronische Version(en): https://doi.org/10.1002/smll.202007908 (Zugang: Offen)