DFT study of bare and dye-sensitized TiO2 clusters and nanocrystals
2006 (English)In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 106, no 15, 3214-3234 p.Article in journal (Refereed) Published
Structural and electronic properties of bare and dye-sensitized TiO2 clusters and nanoparticles with sizes of ?2 nm have been studied by density functional theory (DFT) calculations. Starting from truncated bulk lattice structures, the degree of structural reorganization, including the formation of Ti dbond O surface species, of bare TiO2 anatase nanocrystals, is found to be sensitive to the quality of the computational method. The electronic structures of optimized 1-2 nm nanoparticles show well-developed band structures with essentially no electronic bandgap defect states. Significant bandgap broadening due to quantum size effects is observed as the size of the nanocrystals is reduced from 2 nm to 1 nm in diameter, but further bandgap widening is limited by increasingly severe competing surface defect sites as the particles become smaller than ?1 nm in diameter. The applicability of the TiO2 nanocrystals in modeling the electronic structure and electronic coupling at dye-sensitized TiO2 nanocrystal interfaces has been investigated by attachment of pyridine to one of the nanoparticle models via phosphonic or carboxylic acid anchor groups.
Place, publisher, year, edition, pages
2006. Vol. 106, no 15, 3214-3234 p.
DFT, TiO2, cluster, nanocrystal, surface electron transfer
IdentifiersURN: urn:nbn:se:uu:diva-94854DOI: 10.1002/qua.21088OAI: oai:DiVA.org:uu-94854DiVA: diva2:168854