Ab initio study of neutral ( TiO2 ) n clusters and their interactions with water and transition metal atoms

Simple item page
dc.citation.epage305301-13en_US
dc.citation.issueNumber30en_US
dc.citation.spage305301-1en_US
dc.citation.volumeNumber24en_US
dc.contributor.authorÇakır, D.en_US
dc.contributor.authorGülseren, O.en_US
dc.date.accessioned2015-07-28T12:05:19Z
dc.date.available2015-07-28T12:05:19Z
dc.date.issued2012-07-04en_US
dc.departmentDepartment of Physicsen_US
dc.description.abstractWe have systematically investigated the growth behavior and stability of small stoichiometric (TiO2)n (n = 1–10) clusters as well as their structural, electronic and magnetic properties by using the first-principles plane wave pseudopotential method within density functional theory. In order to find out the ground state geometries, a large number of initial cluster structures for each n has been searched via total energy calculations. Generally, the ground state structures for the case of n = 1–9 clusters have at least one monovalent O atom, which only binds to a single Ti atom. However, the most stable structure of the n = 10 cluster does not have any monovalent O atom. On the other hand, Ti atoms are at least fourfold coordinated for the ground state structures for n ≥ 4 clusters. Our calculations have revealed that clusters prefer to form three-dimensional structures. Furthermore, all these stoichiometric clusters have nonmagnetic ground state. The formation energy and the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap for the most stable structure of (TiO2)n clusters for each n have also been calculated. The formation energy and hence the stability increases as the cluster size grows. In addition, the interactions between the ground state structure of the (TiO2)n cluster and a single water molecule have been studied. The binding energy (Eb) of the H2O molecule exhibits an oscillatory behavior with the size of the clusters. A single water molecule preferably binds to the cluster Ti atom through its oxygen atom, resulting an average binding energy of 1.1 eV. We have also reported the interaction of the selected clusters (n = 3, 4, 10) with multiple water molecules. We have found that additional water molecules lead to a decrease in the binding energy of these molecules to the (TiO2)n clusters. Finally, the adsorption of transition metal (TM) atoms (V, Co and Pt) on the n = 10 cluster has been investigated for possible functionalization. All these elements interact strongly with this cluster, and a permanent magnetic moment is induced upon adsorption of Co and V atoms. We have observed gap localized TM states leading to significant HOMO–LUMO gap narrowing, which is essential to achieve visible light response for the efficient use of TiO2 based materials. In this way, electronic and optical as well as magnetic properties of TiO2 materials can be modulated by using the appropriate adsorbate atomsen_US
dc.identifier.doi10.1088/0953-8984/24/30/305301en_US
dc.identifier.issn0953-8984
dc.identifier.urihttp://hdl.handle.net/11693/13231
dc.language.isoEnglishen_US
dc.publisherIOP Publishingen_US
dc.relation.isversionofhttp://dx.doi.org/10.1088/0953-8984/24/30/305301en_US
dc.source.titleJournal of Physics: Condensed Matteren_US
dc.titleAb initio study of neutral ( TiO2 ) n clusters and their interactions with water and transition metal atomsen_US
dc.typeArticleen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
10.1088-0953-8984-24-30-305301.pdf
Size:
1.47 MB
Format:
Adobe Portable Document Format
Description:
Full printable version
Download

Collections

Department of Physics