Adsorption of gold atoms on anatase TiO2(100)-1x1 surface


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2009

Öğrenci: KIVILCIM BAŞAK VURAL

Danışman: SÜLEYMAN ŞİNASİ ELLİALTIOĞLU

Özet:

In this work the electronic and structural properties of anatase TiO2 (100) surface and gold adsorption have been investigated by using the first-principles calculations based on density functional theory (DFT). TiO2 is a wide band-gap material and to this effects it finds numerous applications in technology such as, cleaning of water, self-cleaning, coating, solar cells and so on. Primarily, the relation between the surface energy of the anatase (100)-1x1 phase and the TiO2-layers is examined. After an appropriate atomic layer has been chosen according to the stationary state of the TiO2 slab, the adsorption behavior of the Au atom and in the different combinations are searched for both the surface and the surface which is supported by a single Au atom/atoms. It has been observed that a single Au atom tends to adsorb to the surface which has an impurity of Au atom or atoms. Although, the high metal concentration on the surface have increased the strength of the adsorption, it is indicated that the system gains a metallic property which is believed to cause problems in the applications. In addition, the gold clusters of the dimer (Au2) and the trimer (Au3) have been adsorbed on the surface and their behavior on the surface is investigate. It is observed that the interaction between Au atoms in the atomic cluster each other is stronger than that of gold clusters and the surface.