Influence of Experimental Installation on Photocatalytic Activity of Sputtered Nb-Doped TiO 2 Thin Film (original) (raw)
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Vacuum, 2005
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international journal of nano dimension, 2017
In this study, different samples of Niobium and Vanadium co-doped titania thin films (5-10-15 mol% Nb and 5-10-15 mol% V) were prepared via sol−gel dip coating method, using niobium chloride as niobium precursor, ammonium metavanadate as vanadium precursor, and titanium (IV) butoxide (TBT) as titanium precursor. The effects of doping amount on the structural, optical, and photo-catalytic properties of formed thin films have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis absorption and transmission electron microscopy (TEM). XRD patterns showed a decrease in peak intensities of the anatase crystalline phase by increasing the Nb/V dopant and doping inhibition effect on the grain growth, and revealed that all samples contained only anatase phase (T= 475 º C). The photo-catalytic activity of the thin film was measured on degradation rate of methylene blue (MB) solution under UV irradiation. Highest photo-catalytic activity of doped TiO 2 thin films were measured in the TiO 2-5 mol% Nb-15 mol% V sample (TNV4). Small granular crystallites of 10-15 nm 2D diameter were observed in electron microscope micrographs.
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A nitrogen doped TiO 2 thin lm was deposited by a DC reactive magnetron sputtering on glass and SiO2 substrates, and then annealed at 400 C. Deposition was performed in a Ar + O2+N2 gas mixture of 1.0 Pa, and oxygen and nitrogen with constant pressures of 0.2 Pa and 0.1 Pa, respectively. The thicknesses of deposited layers, TiO (2 x) N x /TiO 2 /ZnO, were approximately 200 nm, 800 nm and 80 nm, respectively. ZnO was used as a bu er layer. The structure and morphology of the deposited lms were evaluated by X-Ray Di raction (XRD) and scanning electron microscopy (SEM). The average grain sizes of TiO2 and nitrogen doped annealed thin lms were 25 and 18 nm, respectively. The microstructure of the annealed lms was anatase. The optical transmittance of the lms was measured using ultravioletvisible light (UV-vis) spectrophotometer. The photocatalytic activity of the samples was evaluated by the degradation of Methylene Blue (MB) dye.
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Polish Journal of Chemical Technology, 2015
Titanium dioxide thin films doped with the same amount of neodymium were prepared using two different magnetron sputtering methods. Thin films of anatase structure were deposited with the aid of Low Pressure Hot Target Magnetron Sputtering, while rutile coatings were manufactured using High Energy Reactive Magnetron Sputtering process. The thin films composition was determined by energy dispersive spectroscopy and the amount of the dopant was equal to 1 at. %. Structural properties were evaluated using transmission electron microscopy and revealed that anatase films had fibrous structure, while rutile had densely packed columnar structure. Atomic force microscopy investigations showed that the surface of both films was homogenous and consisted of nanocrystalline grains. Photocatalytic activity was assessed based on the phenol decomposition. Results showed that both thin films were photocatalytically active, however coating with anatase phase decomposed higher amount of phenol. The t...
Photocatalytic activity of sprayed TiO2 films deposited on different substrates
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Photocatalytic properties of nanocrystalline TiO 2 thin films doped with Tb
Cent Eur J Phys, 2011
In this work photocatalytic properties of TiO 2 thin films doped with different amount of Tb have been described. Thin films were prepared by high energy reactive magnetron sputtering process. Comparable photocatalytic activity has been found for all doped TiO 2 thin films, while different amounts of Tb dopant (0.4 and 2.6 at. %) results in either an anatase or rutile structure. It was found that the terbium dopant incorporated into TiO 2 was also responsible for the amount of hydroxyl groups and water particles adsorbed on the thin film surfaces and thus photocatalytic activity was few times higher in comparison with results collected for undoped TiO 2 thin films.
Visible and infrared photocatalytic activity of TiOx thin films prepared by reactive sputtering
TiO x thin films have been deposited on corning glass substrates, using RF magnetron reactive sputtering from a Ti target. The effect of oxygen mass flow (OMF) used during the growth of the films on their physical and photocatalytic properties was investigated. The properties of the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The films presented a stratified structure with the surface layer having the stoichiometric characteristics of TiO 2 while the inner layer contained a mixture of TiO 2 , Ti 2 O 3 and TiO oxides. The photocatalytic efficiency was evaluated by the photodegradation of a methylene blue aqueous solution. The samples showed a photocatalytic activity in the visible and visible-NIR light spectrum, depending on the phases of titanium oxides present in the film.
Influence of Nb dopant on the structural and optical properties of nanocrystalline TiO2 thin films
Materials Chemistry and Physics, 2012
In this study, preparation of Nb-doped (0-20 mol% Nb) TiO 2 dip-coated thin films on glazed porcelain substrates via sol-gel process has been investigated. The effects of Nb on the structural, optical, and photocatalytic properties of applied thin films have been studied by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Surface topography and surface chemical state of thin films was examined by atomic force microscope and X-ray photoelectron spectroscopy. XRD and Raman study showed that the Nb doping inhibited the grain growth. The photo-catalytic activity of the film was tested on degradation of methylene blue. Best photo-catalytic activity of Nb-doped TiO 2 thin films were measured in the TiO 2 -1 mol% Nb sample. The average optical transmittance of about 47% in the visible range and the band gap of films became wider with increasing Nb doping concentration. The Nb 5+ dopant presented substitutional Ti 4+ into TiO 2 lattice.
Titanium dioxide thin films: the effect of the preparation method in their photocatalytic properties
Journal of Molecular Catalysis A-chemical, 2005
Titanium dioxide thin films were deposited by DC reactive magnetron sputtering and spray pyrolysis methods on glass and glass coated with fluorine tin oxide (FTO). The films were characterized by X-ray diffraction, scanning and transmission electron microscopy, atomic force microscopy and UV–vis spectroscopy. The influence of a reactive atmosphere: a 50/50 Ar–O2 mixture on TiO2 thin films deposited by sputtering has been studied following the evolution of surface and structural properties and has been correlated, when possible, with photocatalytic properties under UV illumination. Also transparent TiO2 thin films have been prepared by spray pyrolysis using a low concentration of titanium precursor and different substrates temperatures. At higher substrate temperatures the films were polycrystalline in anatase phase; at lower substrate temperatures the films presented amorphous configuration. The best photocatalytic activity was found for films deposited by spray pyrolysis at Ts = 450 °C and for those deposited by magnetron sputtering those deposited at 16 mTorr gave the higher photodegradation rates.The behavior of photodegradation of methylene blue on TiO2 thin films when illuminated with UV radiation can be observed in the graphic. For films deposited by magnetron sputtering the variation is followed for pressure increasing in the sputtering chamber. For films deposited by spray pyrolysis the influence of substrate temperature on the photocatalytic activity of TiO2 thin films can be followed from the graphic. The best results are obtained in films deposited at 16 mTorr and with Ts = 400 °C, respectively.