Tailoring the functionality of transition metal oxide surfaces and interfaces for energy conversion applications
19th. May. 2022, ICAMS IfM Seminar, online seminar via zoom
Time:
Start: 19th. May. 2022. 12:00
End: 19th. May. 2022. 01:00 p.m.
Author(s):
R. Pentcheva Duisburg-Essen University
Organizer(s):
A. Grünebohm ICAMS, Ruhr-Universität Bochum
Abstract:
Transition metal oxides are prospective candidates for energy conversion applications e.g. as thermoelectrics or catalysts for the (photo-) electrocatalytic water splitting due to their abundance, chemical and thermal stability and, in particular, to the interplay of orbital, spin and lattice degrees of freedom. Nanostructuring and reduced dimensionality can lead to further functionalities that are not available in the bulk compounds. By combining DFT+U calculations and Boltzmann transport theory we explore the effect of interface polarity, confinement and strain to tune the thermoelectric properties of oxide superlattices [1-4]. Moreover, several examples for the application of density functional theory (DFT) calculations with a Hubbard U term to model, understand and tailor the catalytic activity of anode materials for the oxygen evolution reaction (OER) will be addressed. The comparison between iron and cobalt spinels [5-6] vs. perovskites [7] allows us to disentangle the role of structural motifs, crystallographic orientation and dopants. Analysis of the underlying electronic and magnetic properties indicates dynamic variation of oxidation state during OER and points towards potential active sites.
Funding by the German Research Foundation DFT within CRC TRR80 (Projects G3, G8) and TRR247 (Project B04) as well as computational time at the Leibniz Rechenzentrum and the supercomputer MagnitUDE at UDE is gratefully acknowledged.