Synthesis of Titania coated Alumina Particles by a Hybrid Sol-gel Method

2002 ◽  
Vol 740 ◽  
Author(s):  
A.D. Schmidt ◽  
S.B. Majumder ◽  
P.S. Dobal ◽  
R.S. Katiyar ◽  
D.C. Agrawal
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Microscopy Imaging ◽  
Nano Crystalline ◽  
Heat Treated ◽  
Alumina Particles ◽  
Gel Technique ◽  
Titania Coatings ◽  
Titania Coating

ABSTRACTModifying their surface with a coating of another ceramic material can dramatically alter the properties of ceramic particles. In the present work we have demonstrated that the Al2O3 particles can be successfully coated by TiO2 using a novel sol-gel technique. The nature of these coatings was predicted on the basis of scanning electron microscopy imaging in conjunction with the micro-Raman scattering measurements. The surface morphology of these particles shows that either individual or group of sub-micron alumina particles are coated with the nano-crystalline titania particles. The thickness of the titania coating could be varied by changing the precursor sol concentration. Amorphous titania was converted to anatase phase at 400°C and upon further heating it started transforming to rutile phase, and both these phases coexisted in the coated particles that were heat treated up to 800°C. The mechanical strength of the titania coating was measured qualitatively by ultrasonicating the coated powders for longer duration to observe that titania coatings are strongly adhered with the alumina particles.

Growth of TiO2 Nanotube Arrays using Porous Anodic Alumina Templates

2013 ◽  
Vol 1601 ◽  
Author(s):  
A. Shoja ◽  
A. Nourmohammadi ◽  
M. H. Feiz
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Nanotube Arrays ◽  
Nanoporous Alumina ◽  
Heat Treated ◽  
Semiconductor Behavior ◽  
Dc Electric Field ◽  
Nanoporous Alumina Templates ◽  
Anodic Alumina Templates

ABSTRACTThe aim of this research study is to produce high quality TiO2 nanotube arrays. It is shown that sol-gel electrophoresis is a suitable one to obtain vast-area TiO2 nanotube arrays when nanoporous alumina templates are used. To fabricate TiO2 nanotube arrays, alumina templates were produced via a two-step anodizing by a homemade anodizing cell using high purity phosphoric acid as the electrolyte with aluminum and platinum as electrodes. The semiconductor behavior of these templates can also be employed when producing conducting substrates for the grown TiO2 nanotubes. Stabilized titanium sol was prepared by modified hydrolysis of the titanium precursor using acetic acid. In order to produce TiO2 nanotube arrays, the template pores were filled with the precursor sol by applying a DC electric field. Then, the filled template was heat treated to crystallize the desired TiO2 phase. Scanning electron microscopy of TiO2 nanotube arrays showed that the nanotubes have been deposited in the channels of the nanoporous alumina template. X-ray diffraction data confirmed phase structure and composition of TiO2 nanotube arrays after heat treatment. To reach pure anatase phase, the samples were heated at 320°C and 400°C for two hours. To obtain pure rutile phase, the samples were heated at 320°C and 750°C for two hours.

Modification of the phase transition temperatures in titania doped with various cations

1997 ◽  
Vol 12 (2) ◽  
pp. 439-443 ◽  
Author(s):  
R. Rodríguez-Talavera ◽  
S. Vargas ◽  
R. Arroyo-Murillo ◽  
R. Montiel-Campos ◽  
E. Haro-Poniatowski
Keyword(s):  
Phase Transition ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Transition Temperatures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Transition Temperatures ◽  
Gel Technique ◽  
Almost All

Titania matrices prepared by a sol-gel technique were doped with several cations (La, Zn, Al, K, Na, Ca, Ba, and Co). The effect of the dopants on the thermal and structural properties of the materials is analyzed. The dopant concentration was 2% mol with respect to titanium, and in all cases the same anion (nitrate) was used. The transition temperatures from amorphous to anatase and from anatase to rutile were measured using x-ray diffraction. The amorphous-anatase transition is independent, for almost all samples, of the type of dopant used; however, the anatase-to-rutile phase transition depends strongly on the kind of cation. This means that the temperature range where the anatase phase exists can be controlled by choosing the appropriate dopant. We have found a correlation between the anatase-rutile phase transition temperature and the radius of the cations and their electric charge.

scholarly journals Investigation of Photocatalytic Activity of TiO2 Nanoparticles Synthesized By Sol-Gel Technique

2021 ◽  
Author(s):  
R. S. Gedam ◽  
G. K. Sukhadeve ◽  
S.Y. Janbandhu ◽  
S. Upadhyay
Keyword(s):  
Photocatalytic Activity ◽  
Anatase Phase ◽  
Sol Gel ◽  
Optical Absorption Spectra ◽  
Energy Band Gap ◽  
Tem Analysis ◽  
Xrd Study ◽  
Heat Treated ◽  
Gel Technique ◽  
Scanning Electron

Abstract Anatase phase TiO2 nanoparticles were synthesized by sol-gel method using titanium(IV) butoxide as a starting material. The pH of solution was maintained by adding HNO3 and NaOH. The obtained powder was heat treated at 350̊ C for 2 hours. The XRD study shows that the crystalline size and crystalinity of samples increases with pH of solution. Raman spectra confirm the dominance of anatase phase of TiO2. Morphology study of samples was done by scanning electron microscope (SEM). The size of prepared samples was calculated by XRD and confirmed by TEM analysis. The energy band gap was calculated by optical absorption spectra and it was found to decrease by increasing pH of the solution. The photodegration activity of IC dye under visible light irradiation was carried out by synthesized TiO2 Nanoparticles.

Probing the Phase Transition in Nanocrystalline TiO2 Powders by Positron Lifetime (PAL) Technique

2011 ◽  
Vol 319-320 ◽  
pp. 151-159 ◽  
Author(s):  
E.M. Hassan ◽  
Basma A.A. Balboul ◽  
M.A. Abdel-Rahman
Keyword(s):  
Positron Annihilation ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Positron Annihilation Lifetime ◽  
Nanocrystallite Size ◽  
Heat Treated ◽  
Degussa P25

Positron annihilation techniques (PAT) have recently been successfully employed for the characterization of phase transitions in metals and compounds. In the present study, positron annihilation lifetime (PAL) measurements have been carried out on a nanocrystalline titania (TiO2) in the form of powders that had been heat-treated at temperatures ranging from 300 to 1273K. The PAL spectra were analyzed into two lifetime components. The shorter lifetime τ1 (185-300 ps) is attributed to positron annihilation in vacancies and the longer lifetime τ1 (400-580 ps) to positrons in microviods at interfaces. The rutile phase of TiO2 powders was utilized as a reference in order to compare their behavior with the commercially supplied and widely available anatase phase (Degussa P25). The influence of the heat-treatment upon the nanostructure during the transition of the anatase to rutile phase were also investigated by X-ray diffraction (XRD), TEM and BET surface area methods. Understanding of this effect is expected to enhance our knowledge of the morphology and nanocrystallite size of TiO2 powders and their T-dependence, and hence their physical properties.

Structural and Optical Characterization of Synthesized TiO2 Nanopowder Using Sol–Gel Technique

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650002 ◽  
Author(s):  
S. Lourduraj ◽  
R. Victor Williams
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Visible Spectrum ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Morphological Studies ◽  
Atomic Force ◽  
Gel Technique

The nanocrystalline TiO2 powder was synthesized by sol–gel method. The XRD analysis reveals that TiO2 powder was highly crystalline (anatase phase) and nanostructured with tetragonal system. The average crystallite size after calcined at 673[Formula: see text]K is found to be 7.7[Formula: see text]nm. The surface morphological studies using scanning electron microscopy (SEM) exhibit that the formation of nanosized TiO2 particles with less densification nature. Atomic force microscopy (AFM) topography exhibits the uniform distribution of spherical-shaped particles. The energy dispersive X-ray spectroscopy (EDX) confirms the presence of Titanium and Oxygen in synthesized TiO2 nanopowder. The value of optical bandgap of TiO2 nanopowder calculated from UV-Visible spectrum is 3.45[Formula: see text]eV. The presence of TiO2 particles is confirmed from the dominant fourier transform infrared (FTIR) peaks at 621[Formula: see text]cm[Formula: see text] and 412[Formula: see text]cm[Formula: see text].

Sol-Gel Synthesis of SnO2-TiO2 System - Morphologic, Photocatalytic and Antibacterial Properties

2018 ◽  
Vol 762 ◽  
pp. 273-277
Author(s):  
Anzelms Zukuls ◽  
Gundars Mežinskis ◽  
Aigars Reinis ◽  
Ingus Skadins ◽  
Juta Kroica ◽  
...  
Keyword(s):  
Sol Gel ◽  
Antibacterial Properties ◽  
Soda Lime ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
Oxide Coatings ◽  
Atomic Force ◽  
Heat Treated ◽  
Soda Lime Silicate Glass ◽  
Sol Gel Synthesis

SnO2-TiO2 sol-gel coatings on soda-lime silicate glass heat treated at 500 °C and xerogel specimens also heat treated at 500 °C were investigated in this study. The morphology of 1, 3, 5 and 7 mol% SnO2 doped titanium oxide coatings were evaluated with a scanning electron microscope (SEM), an atomic force microscope (AFM) and an UV-VIS light spectrophotometer, whilst xerogel structure was analysed with X-ray diffraction spectroscopy (XRD). The physicochemical properties of the TiO2-SnO2 systems depended mainly on the Sn-to-Ti ratio. The surface morphology of the layer was compact and homogeneous with no visible cracks. Anatase and rutile phase was found in the tested 1, 3, 5, 7 and 10 mol% SnO2 doped and heat treated xerogel specimens. Rutile phase content in the heat treated xerogel was reduced, if Sn4+ content was increased. Photocatalytic activity and antibacterial properties were evaluated as well.

Study on the Properties of Al-Al2O3 Composite Using Synthesized Alumina from Sol Gel Technique

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Hasmaliza Mohamad ◽  
Hanisah Abdul Rani
Keyword(s):  
Metal Matrix ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Comparison Study ◽  
Commercial Alumina ◽  
Al2o3 Composite ◽  
Alumina Particles ◽  
Gel Technique ◽  
Ideal Method ◽  
The Ideal

Alumina reinforced aluminum is one of metal matrix composite (MMC) systems that can maintain its properties although at high temperature. Among various processes to produce MMC, powder metallurgy is the best method because of its efficiency dispersion of fine alumina particles. In this study, alumina powders were synthesized through sol gel method which is known as one of the ideal method to produce good properties of powders. The performances of synthesized alumina powders were then observed through the fabrication of composite. The percentage of alumina (0wt%, 10wt%, 20wt% and 30wt %) and sintering temperature (500°C and 550°C) were varied in order to observed their effects on the produced composite. Result shows that by increasing the percentage of alumina and sintering temperature, mechanical properties were increased where 30wt% alumina and 550°C sintering temperature give the optimum results. Comparison study by using 30wt% alumina and 550°C sintering temperature on the composite using synthesize and commercial alumina shows similar/comparable properties of composite.

Structural, Optical and Magnetic Properties of Nanocrystalline Cobalt Doped TiO2 Prepared by Sol-Gel Route

2013 ◽  
Vol 24 ◽  
pp. 168-175
Author(s):  
Kirit S. Siddhapara ◽  
D.V. Shah
Keyword(s):  
Magnetic Properties ◽  
Anatase Phase ◽  
Sol Gel ◽  
Photo Luminescence ◽  
Rutile Phase ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Drying Treatment

Nanocrystalline Cobalt-doped TiO2was prepared by Sol-Gel technique, followed by freeze-drying treatment at-30°C temperature for 12hrs. The obtained Gel was thermally treated at 200,400,600, 800°C. 1%, 2% and 4% Cobalt doped TiO2nanopowder has been prepared X-ray Powder Diffraction (XRD), Scanning Electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), was used to study its structural properties. The XRD pattern shows the coexistence of anatase phase and rutile phase. Thermal gravimetric analysis shows Cobalt concentration affects thermal decomposition. UV-Vis Spectroscopy, Photo luminescence (PL), was used to study its Optical properties. Optical Bandgap were calculated with the incorporation of different concentration of cobalt. UV-Visible spectroscopy show variation in band gap for the sample treated at different temperature for same concentration. All Cobalt doped TiO2nanostructures shows an appearance of Red shift relative to the bulk TiO2. The determination of magnetic properties was also carried out by Vibrating Sample Magnetometer.

Effect of Vapor Pressure of H2O on the Formation of Nano-Crystalline TiO2 Ultrafine Powders

1999 ◽  
Vol 581 ◽  
Author(s):  
K. R. Lee ◽  
S. J. Kim ◽  
J. S. Song ◽  
S. Park
Keyword(s):  
Vapor Pressure ◽  
Reaction Rate ◽  
Ph Value ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Precipitation Process ◽  
Nano Crystalline ◽  
Natural Decrease ◽  
Spontaneous Hydrolysis ◽  
Hydrolysis Of

ABSTRACTMono-dispersed TiO2 ultrafme particles with diameters 40-400nm were obtained from aqueous TiOCl2 solution with 0.67M Ti4+ concentration prepared diluting TiCl4 by homogeneous precipitation process in the ranges of 17-230°C. With the spontaneous hydrolysis of TiOCl2, which means the natural decrease of pH value in the aqueous solution, all mono-dispersed precipitates were crystallized with the anatase or rutile TiO2 phase. TiO2 precipitate with the pure rutile phase was fully formed at the temperatures below 65 °C, not involving the evaporation of H2O, and above 155 °C, which were available by suppressing it. TiO2 precipitate with rutile phase including a small amount of the anatase phase started to be formed in the intermediate temperatures above 70 °C showing the full formation of the anatase above 95 °C under the free evaporation of H2O. However, in the case of completely suppressing H2O evaporation at the temperatures above 70°C, TiO2 precipitate with anatase phase was fully transformed into the precipitate with the rutile phase by the vapor pressure of H2O. Therefore, the formation of TiO2 precipitates with the rutile phase around room temperature would be caused due to the existence of the capillary pressure between the agglomerated needle-shaped particles or the ultrafme clusters, together with the slow reaction rate.

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