Microstructures and Visible Photoluminescence of TiO2 Nanocrystals

Abstract

Nanocrystalline titanium dioxide (TiO 2 ) of anatase structure was prepared by a hydrolysis process of tetrabutyl titanate. The microstructures were examined by X-ray diffraction and Raman spectroscopy. The TiO 2 nanocrystals with particle sizes from 6.8 to 27.9 nm were obtained through an annealing treatment of the as-prepared nanocrystals at various temperatures. Photoluminescence (PL) properties of TiO 2 nanocrystals were investigated at various annealing temperatures (particle sizes), exciting powers, and exciting photon energies, respectively. The strongest visible emission was observed in the nanocrystals annealed at 300 C, with a particle size of 7.9 nm. The experimental results manifested that the visible PL arises from a radiative recombination of electrons via intrinsic surface states of TiO 2 nanoparticles.

Synthesis characterization and luminescence studies of 100MeV Si8+ ion irradiated sol gel derived nanocrystalline Y2O3

“…The radiation source may be infrared, visible, ultraviolet or X-ray. PL is an extremely useful tool for obtaining information about the electronic, optical and photoelectric properties of materials [12].…”

Effects of crystallization and dopant concentration on the emission behavior of TiO2:Eu nanophosphors

“…As TiO 2 is a strongly ionic metal oxide, the filled valance band is mainly composed of the outermost 2 p orbitals of oxygen atoms, and the lowest conduction band is derived from titanium 3 d orbitals. When some titanium atoms are exposed to the surface of nanoparticles, they get oxidized into Ti +3 , Ti +2 , or Ti + oxidation states, and localized energy levels are introduced within the forbidden gap [38]. These intrinsic surface states act as luminescence centers under an appropriate excitation as can be seen in the present work.…”

Synthesis characterization and luminescence studies of gamma irradiated nanocrystalline yttrium oxide

“…The average crystallite size is found to be in the range [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] during combustion [19]. The lattice strain and crystallite size are estimated using Williamson-Hall (W-H) equation [20],…”

“…However, efforts are still being made for improving the TL dosimetric properties by using different fuels. TL technique has attracted many researchers from all over the world since this technique is simple and finds wide applications in various fields such as radiation therapy, space research, geology, archeology and other related areas [14][15][16]. Yttrium oxide (yttria) finds potential application because of its high corrosion resistivity and thermal stability.…”