First-principles study of atomic structure and electronic properties of Si and F doped anatase TiO₂

Abstract

Chemical doping represents one of the most effective ways in engineering electronic structures of anatase TiO 2 for practical applications. Here, we investigate formation energies, geometrical structures, and electronic properties of Si-, F-doped and Si/F co-doped anatase TiO 2 by using spin-polarized density functional theory calculation. We find that the co-doped TiO 2 is thermodynamically more favorable than the Si-and F-doped TiO 2 . Structural analysis shows that atomic impurity varies crystal constants slightly. Moreover, all the three doped systems show a pronounced narrowing of band gap by 0.33 eV for the F-doped TiO 2 , 0.17 eV for the Si-doped TiO 2 , and 0.28 eV for the Si/F-co-doped TiO 2 , which could account for the experimentally observed redshift of optical absorption edge. Our calculations suggest that the Si/F-co-doping represents an effective way in tailoring electronic structure and optical properties of anatase TiO 2 .

Understanding the synergistic effects, optical and electronic properties of ternary Fe/C/S‐doped TiO2 anatase within the DFT + U approach

“…For the undoped TiO 2 , the valence band minimum is dominated by O 2p state, while the conduction band maximum consists of Ti 3d state with some contribution from O 2p and Ti 4s states (Figure (A)). The PDOS analysis of the undoped TiO 2 is comparable to other results . This is one of the most significant factors to limit the photocatalytic activity of undoped TiO 2 .…”

Review—Recent Progress in Low Temperature Synthesis of Crystalline TiO2 Photocatalytic Films by Highly Controllable Electrodeposition

“…18,19 They can be deposited by several processes, and engineering possibilities at the micro-and nanoscale, either observed experimentally or theoretically, enable surface modifications in a chemical and physical way. [20][21][22][23][24][25][26] In this regard, sol-gel method has become a very common and simple experimental approach, which is effective and reliable. 27 However, since efficient photocatalytic performance is typically only observed for crystalline TiO 2 , most of the deposition methods must be followed by a heat treatment step in order to crystallize the amorphous phases.…”