Search results for "Scanning electron microscope"
showing 10 items of 615 documents
Photoluminescence: A very sensitive tool to detect the presence of anatase in rutile phase electrospun TiO 2 nanofibers
2015
Abstract This paper reports on the synthesis and the characterization of titanium dioxide (TiO2) nanofibers prepared by electrospinning. The samples were annealed at various temperatures in air for 4 h. The as-spun and annealed TiO2/PVP composite nanofibers were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy analysis (EDX), X-ray diffraction (XRD), Raman spectroscopy and photoluminescence (PL). The results show that the heat treatment has an effect on the crystallization process. Even if the XRD data shows a complete anatase-to-rutile transition in the TiO2 nanofibers at 900 °C, photoluminescence reveals a small portion of anatase in rutile sample.…
Black carbon-doped TiO2 films: Synthesis, characterization and photocatalysis
2019
This research is funded by the European Social Fund according to the activity ‘Improvement of researchers’ qualification by implementing world-class R&D projects’ of Measure No. 09.3.3-LMT- K-712, project „Investigation of the application of TiO2 and ZnO for the visible light assisted photocatalytical disinfection of the biologically contaminated water“ (09.3.3-LMT-K-712-01-0175). The authors express gratitude for the S. Tuckute, M. Urbonavicius, G. Laukaitis and K. Bockute for their valuable input in current work. © 2019. This work is licensed under a CC BY-NC-ND 4.0 license.
Photocatalytic thin films of TiO2 formed by a sol-gel process using titanium tetraisopropoxide as the precursor
2008
Abstract Thin TiO 2 films were prepared with the dip-coating technique by using sols deriving from titanium tetraisopropoxide. TiO 2 films were formed on glass substrates previously covered by a SiO 2 layer obtained from a tetraethylortosilicate sol. The films, after a thermal treatment at 673 K, mainly consisted of TiO 2 anatase. The samples were characterised by X-ray diffraction, UV–Vis spectroscopy, scanning electron microscopy and atomic force microscopy. The photoactivity of the various films was tested by using as probe reaction the photo-oxidation of 2-propanol in gas-solid regime. The photoreactivity results indicated that the TiO 2 films were efficient for degrading 2-propanol und…
Sol-gel derived anatase TiO2: morphology and photoactivity
1994
Abstract High-surface area TiO 2 (anatase) was prepared by the sol-gel method and characterized by various instrumental and analytical methods, including X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, porosimetry, specific surface area measurements, scanning electron microscopy, and titration of surface hydroxyl groups. The specimen was tested for photodegradation of phenol and nitrophenols carried out in aqueous suspension at pH = 3; photoactivity was compared with that of commercially available anatase TiO 2 . Results are discussed in terms of porosity, surface area, and availability and population of surface OH groups, consequent upon the particular method used for…
Preparation and photoactivity of electrophoretic TiO2coating film
2012
TiO2 thin films have been obtained by a sol-electrophoretic deposition method on metallic Ti and Pt substrates. X-ray diffraction, Raman spectroscopy and scanning electron microscopy were used to investigate the structure and morphology of plated materials. Annealed TiO2 films mainly are formed in anatase structure with different morphology depending on substrate material. Light induced potential measurements indicate that the morphology substantially have an impact on photoactivity of TiO2 thin films.
Phase formation in mixed TiO2-ZrO2 oxides prepared by sol-gel method
2011
Pure titania, zirconia, and mixed oxides (3—37 mol.% of ZrO2) are prepared using the sol-gel method and calcined at different temperatures. The calcined samples are characterized by Raman spectroscopy, X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption porosimetry. Measurements reveal a thermal stability of the titania anatase phase that slightly increases in the presence of 3—13 mol.% of zirconia. Practically, the titania anatase-rutile phase transformation is hindered during the temperature increase above 700 C. The mixed oxide with 37 mol.% of ZrO2 treated at 550 C shows a new single amorphous phase with a surface area of the…
High photodegradation and antibacterial activity of BN–Ag/TiO 2 composite nanofibers under visible light
2018
To develop material with good photocatalytic properties for organic compound degradation and bacterial removal, we produced Ag/TiO2 and BN–Ag/TiO2 composite nanofibers that included controlled amounts of boron nitride (BN) nanosheets and silver (Ag). After annealing at 500 °C under air, we used scanning electron microscopy, transmission electron microscopy, Brunauer–Emmet–Teller analysis, X-ray diffraction, energy-dispersive X-ray spectroscopy, Raman spectroscopy, UV-visible reflectance spectroscopy and room temperature photoluminescence to investigate the morphological, structural and optical properties of all samples. The photocatalytic tests using methylene blue under visible light, in r…
New hydrogel matrices based on chemical crosslinked α,β -polyas parthydrazide: Synthesis, characterization and in vivo biocompatibility studies
1996
New swellable micromatrices of α,β-polyasparthydrazide (PAHy) crosslinked with glutaraldehyde were prepared. The effect of crosslinking agent concentration was evaluated. In particular, crosslinking density affected aqueous dynamic swelling and glass-transition temperature of the material. The structure of prepared networks was also studied by scanning electron microscopy and X-ray analysis. Finally, biocompatibility of PAHy derivatives was investigated in vivo by subcutaneous implantation and in oral administration to laboratory animals.
Cation and anion electrochemically assisted solid-state transformations of malachite green
2020
[EN] The possibility of the electrochemical promotion of different solid-to-solid transformations including the performance of successive cation and anion insertion processes has been tested using malachite green, a triphenylmethane dye, in contact with aqueous NaCl electrolyte. Electrochemical data using the voltammetry of microparticles methodology reveal significant differences with the solution phase electrochemistry of the dye. Voltammetric data, combined with atomic force microscopy, focusing ion beam-field emission scanning electron microscopy, and high-resolution field emission scanning electron microscopy permit characterization of the oxidative dissolution, oxidation with anion in…
Composite Thin Film by Hydrogen-Bonding Assembly of Polymer Brush and Poly(vinylpyrrolidone)
2005
Based on hydrogen-bonding layer-by-layer (LBL) assembly in aqueous solution, poly(vinylpyrrolidone) (PVPON) and a spherical polymer brush with a poly(methylsilsesquioxane) (PSQ) core and poly(acrylic acid) (PAA) hair chains were used to fabricate composite multilayer thin films. Hydrogen bonding as the driving force was confirmed by FT-IR spectrometry. A simple method (Filmetric F20) was introduced to determine the thickness and refractive index of the films. The film thickness was found to be a linear function of the number of bilayers. The average increase in thickness per bilayer is 28.3 nm. The film morphology was characterized with scanning electron microscopy and atomic force microsco…