Post-graduate theses
Current Record: 63 of 123
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Identifier |
000421865 |
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h |
Title |
First-principle Simulations for Photocatalytic Nanomaterials |
Alternative Title |
Προσωμοιώσεις πρώτων αρχών για φωτοκαταλυτικά νανοϋλικά |
Author
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Βριθιάς, Νικόλαος-Ραφαήλ
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Thesis advisor
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Ρεμεδιάκης, Ιωάννης
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Reviewer
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Κοπιδάκης, Γεώργιος
Κατσαράκης, Νικόλαος
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Abstract |
We investigate the structure and properties of photocatalytic nanomaterials by using ab initio calculations using Density-Functional Theory (DFT). We focus on nanostructures of ZnO with substitutional Mn doping of the outmost surface layers.
We begin by extensive preparatory benchmark calculations of the atomic and electronic structure of Zn, Ti, O2, wurtzite ZnO and anatase TiO2 in order to find the optimum computational parameters for our simulation. We simulate O- and metal-terminated slabs of ZnO(0001) and ZnO(000i) surfaces with five different concentrations of Mn on the surface Zn layer. For each case, we calculate the surface energy (γ), which is a measure of the stability, and the workfunction (φ), which is a descriptor of the photocatalytic activity.
We find that O-terminated surfaces are by far more stable than metal-terminated ones in all cases, and they always have higher workfunctions. Doping by Mn increases the stability while at the same time it lowers the workfunction. Therefore, Mn is the ideal dopant for this system and it can be used to fine-tune the photocatalytic activity of ZnO.
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Language |
English |
Subject |
Photocatalysis |
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Φωτοκατάλυση |
Issue date |
2019-03-29 |
Collection
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School/Department--School of Sciences and Engineering--Department of Materials Science and Technology--Post-graduate theses
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Type of Work--Post-graduate theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/3/0/7/metadata-dlib-1554106909-667687-25248.tkl
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Views |
288 |