Titanium dioxide nanostructures for photocatalytic and photovoltaic applications

Abstract

Titanyum dioksit cesitli ortamlarda kimyasal olarak dayanikli, cevre dostu ve uretilmesi kolay ve ucuz olan bir metal oksittir.Titanyum dioksitin bir cok uygulamalari onun genellikle optik ozellikleriyle ilgilidir. Biz bu tezde,titanyum-dioksit tabanli nanotel, nanoparcacik ve yuzeyler ilebu nano yapilarin fotokatalitik ve fotovoltaik uygulamalari yogunluk fonksiyoneli teorisine dayanan temel prensipler yontemi kullanilarak inceledik.

TiO2 is widely used in various applications, since it is chemically stable in different conditions, firm under illumination, non toxic, and relatively easy and cheap to produce. Most of the technological applications such as photovoltaic and photocatalytic of TiO2 are mainly related to its optical properties. In this thesis, TiO2 nanostructures and their photocatalytic and photovoltaic applications have been investigated by using the first-principles calculations based on density functional theory. We have concentrated on three different systems, namely small (TiO2)n (n=1-10) clusters, atomically thin TiOx (x=1,2) nanowires and surfaces. Their structural and electronic properties and possible implantations of these titania structures to photovoltaic and photocatalytic applications have been investigated by plane-wave pseudopotential calculations. In addition, Anatase (001) and rutile (110) titania surfaces and their interactions with perylene-based dye molecules (BrPDI, BrGly, and BrAsp) as well as Pt and bimetallic PtAu clusters have been studied. We believe that our results are fundamental and useful for the photovoltaic and photocatalytic applications of titania nanostructures.