Oxygen release and structural changes in TiO2 films during photocatalytic oxidation

Abstract

Changes in the crystal structure and grain modifications in titanium oxide ͑TiO 2 ͒ thin films were observed during the photocatalytic oxidation of hydrocarbons. When the hydrocarbon and collodion films were irradiated, single crystalline titanium oxide transformed into polycrystals. The titanium oxide films gradually became network aggregates. These changes were analyzed with a dedicated in situ transmission electron microscope and observed three dimensionally by electron tomography. A detailed analysis of electron energy loss spectra of the samples also revealed that the changes were associated with the loss of oxygen atoms in the TiO 2 crystal lattice. Correlations between the polycrystalline grain size of TiO 2 and its catalyst activity were discussed based on the measured data.

Preparation of strain-included rutile titanium oxide thin films and influence of the strain upon optical properties

“…1(b) is a HRTEM image of a film. The lattice fringes showed an interplanar spacing of 0.32 nm, which corresponded to the (110) planes of rutile TiO 2 structure [17]. The present films prepared by PLD were quite homogeneous, which mainly comprised of rutile type titanium dioxide crystallites.…”

Soft x-ray reflectometry, hard x-ray photoelectron spectroscopy and transmission electron microscopy investigations of the internal structure of TiO2(Ti)/SiO2/Si stacks

“…TiO 2 films are being extensively studied because of their interesting chemical, electrical and optical properties resulting in widespread applications, e.g., in catalysis, photocatalysis, dye-sensitized photovoltaic cells, gas sensors [6][7][8][9] and pharmaceuticals [10][11][12]. Besides, TiO 2 nanofilms are widely used as protective layers for very large-scale integrated (VLSI) circuits and as antireflective (AR) coatings for optical elements and planar waveguides.…”

Quantification of metallic nanoparticle morphology on TiO2 using HAADF-STEM tomography

“…The Au and Ag nanoparticles on TiO 2 are well known as high active oxidation catalysts, and much 3D research of these catalysts has been reported [26][27][28]. HAADF-STEM tomography has proven to be a quite effective tool for analyzing such catalytic nanomaterials [29][30][31].…”