Reminder TODAY: CMSP Seminar (Atomistic Simulation Seminar Series) 11:00hrs, G. Melani

[CMSP Seminars Secretariat]

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CMSP Seminar (Atomistic Simulation Seminar Series)
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*Friday, 29 September 2023, 11:00 hrs*
*/Oppenheimer Room (Leonardo Building, second floor)/*/Zoom registration 
link: 
/https://zoom.us/meeting/register/tJUkd-yvrDsiE9PBivfmapjVXdoaoDfpsFZ8//

Speaker:*  Giacomo Melani * (Pritzker School of Molecular Engineering, 
University of Chicago & Istituto CNR di Chimica dei Composti 
Organometallici, Pisa).

Title: *Structure and reactivity of bismuth vanadate-water interfaces*

Abstract:

Bismuth vanadate (BVO) is a promising photoanode for 
photoelectrochemical cells, due to its tunable band gap (~2.4 – 2.6 eV), 
favorable alignment of its valence band with the water oxidation 
potential, stability in aqueous environments, and its relative easiness 
of preparation ^[1] . In a recent study ^[2] , we showed that tuning 
surface termination/composition and hence surface energetics is critical 
to improve the efficiency of the oxygen evolution reaction (OER) ^[2] . 
In addition, we highlighted ^[3] the importance of surface defects in 
altering the reactivity of BVO toward water, concomitant to water 
modifications to the electronic structure of the photoanode. However, a 
complete atomistic description of the interface between defective facets 
of BVO and water is not yet available, and yet it is necessary for the 
optimization of the OER efficiency. Here we carry out first principles 
molecular dynamics simulations with the Qbox code (http://qboxcode.org/) 
of BVO-water interfaces with different composition, as well as 
measurements of the electronic (XPS) and vibrational (IRRAS) spectra of 
water-covered BVO thin films. We combine theoretical and experimental 
results on spectra and computed electronic properties to characterize 
the interplay between surface hydroxylation and metal oxidation states 
at the surface, and to understand their impact on surface reactivity.

^[1] T. W. Kim and K.-S. Choi, Science (2014).
^[2] D. Lee, W. Wang et al. Nat. Energy (2020).
^[3] W. Wang et al. J. Am. Chem. Soc., (2022).

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CMSP, Condensed Matter & Statistical Physics Section
http://www.ictp.it/research/cmsp.aspx

The Abdus Salam International Centre for Theoretical Physics
https://www.ictp.it/

    
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