Maluta, N. E.Maphanga, R. R.Nemudzivhadi, Hulisani2019-06-052019-06-052019-05-18Nemudzivhadi, Hulisani (2019) Computational study of low index surface of an anatase TiO2 doped with ruthenium (Ru) and strontium (sr) for application in Dye sensitized solar cells, University of Venda, South Africa,<http://hdl.handle.net/11602/1341>.http://hdl.handle.net/11602/1341MSc (Physics)Department of PhysicsTitanium dioxide (TiO2) is considered to be an ideal semiconductor for photocatalysis because of its high stability, low cost and safety towards both humans and the environment. Doping TiO2 with different elements has attracted much attention as the most important way of enhancing the visible light absorption, in order to improve the efficiency of the dye sensitized solar cells (DSSCs). In this study, first principle density functional theory was used to investigate electronic and optical properties of bulk anatase TiO2, undoped, and ruthenium (Ru) and strontium (Sr) doped anatase TiO2 (1 0 0) surface. Two different doping approaches i.e., substitutional and adsorption mechanisms were considered in this study. The results showed that absorption band edges of Ru and Sr-doped anatase TiO2 (1 0 0) surface shift to the long wavelength region compared to the bulk anatase TiO2 and undoped anatase TiO2 (1 0 0) surface. Also, the results revealed that the band gap values and the carrier mobility in the valence band, conduction band and impurity energy levels have a synergetic influence on the visible-light absorption and photocatalytic activity of the doped anatase TiO2 (1 0 0) surface. Furthermore, according to the calculated results, we propose the optical transition mechanisms of Ru and Sr-doped anatase TiO2 (1 0 0) surface. Thus, we conclude that the visible light response of TiO2 can be modulated by doping with both Ru and Sr. However, Sr-doped system shows higher photocatalytic activity than the Ru-doped system. The study has successfully probed the interesting optical response mechanism of TiO2 (1 0 0) surface.1 online resource (x, 74 leaves : color illustrations)enUniversity of VendaDopingUCTDAnataseTiO2Low index surfaceFirst principle densityfunctional theoryElectronic propertiesOptical propertiesPhotocatalytic activity621.31244Titanium dioxideSolar cellsSolar radiationSolar energy -- Climatic factorsSolar greenhousesDissertationNemudzivhadi H. Computational study of low index surface of an anatase TiO2 doped with ruthenium (Ru) and strontium (sr) for application in Dye sensitized solar cells. []. , 2019 [cited yyyy month dd]. Available from: http://hdl.handle.net/11602/1341Nemudzivhadi, H. (2019). <i>Computational study of low index surface of an anatase TiO2 doped with ruthenium (Ru) and strontium (sr) for application in Dye sensitized solar cells</i>. (). . Retrieved from http://hdl.handle.net/11602/1341Nemudzivhadi, Hulisani. <i>"Computational study of low index surface of an anatase TiO2 doped with ruthenium (Ru) and strontium (sr) for application in Dye sensitized solar cells."</i> ., , 2019. http://hdl.handle.net/11602/1341TY - Dissertation AU - Nemudzivhadi, Hulisani AB - Titanium dioxide (TiO2) is considered to be an ideal semiconductor for photocatalysis because of its high stability, low cost and safety towards both humans and the environment. Doping TiO2 with different elements has attracted much attention as the most important way of enhancing the visible light absorption, in order to improve the efficiency of the dye sensitized solar cells (DSSCs). In this study, first principle density functional theory was used to investigate electronic and optical properties of bulk anatase TiO2, undoped, and ruthenium (Ru) and strontium (Sr) doped anatase TiO2 (1 0 0) surface. Two different doping approaches i.e., substitutional and adsorption mechanisms were considered in this study. The results showed that absorption band edges of Ru and Sr-doped anatase TiO2 (1 0 0) surface shift to the long wavelength region compared to the bulk anatase TiO2 and undoped anatase TiO2 (1 0 0) surface. Also, the results revealed that the band gap values and the carrier mobility in the valence band, conduction band and impurity energy levels have a synergetic influence on the visible-light absorption and photocatalytic activity of the doped anatase TiO2 (1 0 0) surface. Furthermore, according to the calculated results, we propose the optical transition mechanisms of Ru and Sr-doped anatase TiO2 (1 0 0) surface. Thus, we conclude that the visible light response of TiO2 can be modulated by doping with both Ru and Sr. However, Sr-doped system shows higher photocatalytic activity than the Ru-doped system. The study has successfully probed the interesting optical response mechanism of TiO2 (1 0 0) surface. DA - 2019-05-18 DB - ResearchSpace DP - Univen KW - Doping KW - Anatase KW - TiO2 KW - Low index surface KW - First principle densityfunctional theory KW - Electronic properties KW - Optical properties KW - Photocatalytic activity LK - https://univendspace.univen.ac.za PY - 2019 T1 - Computational study of low index surface of an anatase TiO2 doped with ruthenium (Ru) and strontium (sr) for application in Dye sensitized solar cells TI - Computational study of low index surface of an anatase TiO2 doped with ruthenium (Ru) and strontium (sr) for application in Dye sensitized solar cells UR - http://hdl.handle.net/11602/1341 ER -