Specialized iNANO Lecture: Cerium oxide ultrathin films and nanoparticles as model reducible oxide systems
Dr. Paola Luches, Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Modena, Italy
Info about event
Time
Location
iNANO meeting room 1590-213, Gustav Wieds Vej 14, 8000 Aarhus C
Dr. Paola Luches
Istituto Nanoscienze
Consiglio Nazionale delle Ricerche
Modena, Italy
Cerium oxide ultrathin films and nanoparticles as model reducible oxide systems
Reducible oxides are materials in which the cations can easily and reversibly switch between two or more oxidation states, leading to the possibility of quickly storing, releasing and transporting oxygen ions. In spite of the wide application of reducible oxides - for example in catalysis, energy conversion and biomedicine – efforts are still required to comprehensively understand and optimize their functionality.
I will present the results of our studies of cerium oxide ultrathin films epitaxially supported on a Pt(111) single crystal. The use of model reducible oxide systems allows to clarify important aspects of reducibility related to dimensionality and to the mutual interaction between the oxide and the metal [1]. I will discuss the evolution of the oxide stoichiometry, morphology and surface structure induced by reducing thermal treatments and the reversibility of the observed processes [2]. The modifications of the 4f level and of the 5d band with reduction/oxidation will also be described [3]. Our studies demonstrate a higher reducibility in films of subnanometric thickness compared to the surface of thicker films, which is ascribed to the influence of the charge transferred from the platinum substrate on the surface oxygen vacancy formation energy [3].
The results will be critically compared with the ones obtained on mass-selected cerium oxide nanoparticles prepared by physical methods [4].
- P. Luches, L. Giordano, V. Grillo, G. C. Gazzadi, S. Prada, M. Campanini, G. Bertoni, C. Magen, F. Pagliuca, G. Pacchioni, S. Valeri, Adv. Mater. Interfaces 2, 1500375 (2015).
- P. Luches, F. Pagliuca, S. Valeri, Phys. Chem. Chem. Phys. 16, 18848 (2014).
- G. Gasperi, L. Amidani, F. Benedetti, F. Boscherini, P. Glatzel, S. Valeri, P. Luches, Phys. Chem. Chem. Phys. 18, 20511 (2016).
- M. C. Spadaro, P. Luches, G. Bertoni, V. Grillo, S. Turner, G. Van Tendeloo, S. Valeri, S. D'Addato, Nanotechnology 27, 425705 (2016).
Host: Associate professor Jeppe Vang Lauritsen,iNANO &6 Dept. of Physics and Astronomy, AU