On the Sol-gel Synthesis and Characterization of Titanium Oxide Nanoparticles

2011 ◽  
Vol 1352 ◽  
Author(s):  
Varun Chaudhary ◽  
Amit K. Srivastava ◽  
Jitendra Kumar
Keyword(s):  
Band Gap ◽  
Crystallite Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
Finite Size ◽  
Average Crystallite Size ◽  
Photo Luminescence ◽  
Titanium Isopropoxide ◽  
Rutile Phase ◽  
Excitation Wavelength

ABSTRACTTiO2 nanoparticles have been prepared by sol-gel process using titanium isopropoxide as a precursor with ethanol and water as solvents. The synthesis involves gel formation, digestion for 24h, drying at 100oC for 10h, and calcination in air at 500-800oC for 2h. The resulting powder has been studied with respect to phase(s), morphology, optical absorption and photo -luminescence (PL) behaviour. The calcination of dried sol-gel product at 500oC for 2h leads to formation of anatase phase that possesses a tetragonal structure (a = 3.785 Å, c = 9.514 Å, Z = 4), average crystallite size ~ 11 nm and band gap of 3.34 eV. Further, increasing the time (t) of calcination causes crystallite growth that follows the relation d = α – β exp (-t/τ), α = 18.1 nm, β = 9.6 nm and τ = 6.9h. However, calcination of sol-gel product at 800oC for 2h gives rise to a rutile phase (tetragonal a = 4.593Å, c = 2.959Å, Z = 2), average crystallite size ~ 25 nm and band gap of 3.02 eV. The anatase phase exhibits strong PL emission peaks (excitation wavelength 405 nm) at 2.06 and 1.99 eV due to defect levels within the energy band gap. This observation has been attributed to finite size effects occurring in nanoparticles.

scholarly journals Influence of mild Cr3+ doping on the structural, optical, photochromic, and thermochromic reversibility of nano-titania systems

2019 ◽  
Vol 97 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Rizwin Khanam ◽  
Dambarudhar Mohanta
Keyword(s):  
Band Gap ◽  
Anatase Phase ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Incident Radiation ◽  
Optical Absorption Spectroscopy ◽  
Smart Windows ◽  
Cell Parameters ◽  
Doped Titania ◽  
Reversible Thermochromism

We report on the effect of chromium doping on the band gap lowering of nano-titania (TiO2) and subsequent implications as regards coloration characteristics mediated via photochromism and thermochromism processes. As can be found in the X-ray diffractograms, the sol-gel derived, Cr3+-doped nano-TiO2 systems have exhibited an anatase phase with the evidence of peak shifting towards a lower diffraction angle. The average crystallite size decreases, whereas lattice unit cell parameters and, consequently, cell volume, tend to increase with the inclusion of Cr3+ into the titania host. To be specific, 1% Cr-doped titania system showed nearly 5.8% cell expansion as compared to its un-doped counterpart. As revealed from the optical absorption spectroscopy, a narrowing of band gap is observed for the Cr doped nano-titania system: 3.18 eV for the un-doped system, and 2.61 and 2.41 eV for 0.3% and 1% Cr doping cases, respectively, considering direct band-to-band transitions. Moreover, doping led noticeable lowering of the exponent (n value), from its normal value, which suggests inclusion of adequate non-parabolicity feature to the energy band scheme. The photochromic feature, for a given incident radiation, demonstrates a lowered transmission response with increasing Cr content. A reversible thermochromism response has also been demonstrated for doped nano-titania systems subjected to heating with temperature varying between 0–55 °C. The Cr3+ doped nano-titania and similar systems would find scope in smart windows, display components, photocatalysis, etc., when a select coloration is desired.

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.

scholarly journals Preparation and Characterization of XRD Nano Cu-TiO2 using Sol-Gel Method

2018 ◽  
Author(s):  
Arizka Tamarani ◽  
Rahadian Zainul ◽  
Indang Dewata
Keyword(s):  
Crystallite Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Doping Agent ◽  
Gel Method ◽  
Sol Gel Method ◽  
Temperature Range

One of the reported doping agent to increase TiO2 activity is Cu. In this research, TiO2 was prepared by So-Gel method. Preparation was performed by calcinaton at the temperature range of 400, 500, 600ᵒC for 2 hours with a corresponding dopan concentration of 0%, 1%, 3%, 5% mol of TiO2. The nanoparticle materials was characterized using XRD. It is found that anatase phase occur in the calcinations temperature of 400ᵒC and transform to rutile phase at 500ᵒC. The crystallite size of Cudoped TiO2 with dopan concentration of 5% are found 4.63 nm, 8.70 nm, 6.09 nm respectively at 400ᵒC, 500ᵒC, 600ᵒC.

A Study of Photocatalyst of the TiO2 Thin Film with Acid Dispersed CNT for Dye-Sensitized Solar Cell

2010 ◽  
Vol 297-301 ◽  
pp. 764-770
Author(s):  
Yong Woo Kim ◽  
Eun Nara Cho ◽  
Soo Chang Choi ◽  
Deug Woo Lee
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Tio2 Thin Film ◽  
Anatase Phase ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Rutile Phase ◽  
Dye Sensitized Solar Cell ◽  
Dye Sensitized ◽  
Carbon Nano Tubes

M-CNTs (Multiwall Carbon Nano Tubes) can be used as an electrode, transferring electrons and heat very easily. This property helps transfer electrons created in TiO2 layer of DSSC (Dye-sensitized Solar Cell). CNTs layer with TiO2 utilized for the photocatalyst is expected to contribute to improve the efficiency of the solar cell. The Photocatalyst of TiO2 thin film was manufactured from titanium isopropoxide, ethanol, and HCl by a sol-gel process. To determine the property of TiO2 thin film with CNT, we performed to mix acid dispersed CNT in TiO2 Sol-gel and make coating membranes using sol-gel with different densities of CNT. It was found that the crystal structure changed from the anatase phase to the rutile phase having higher efficiency by XRD measure after treatment of high temperature sintering. To demonstrate the property of each sample, the transmittance of the TiO2 thin film was measured by a spectrometer and dispersion of CNT of the thin film was measured by SEM. In conclusion, the capacitance as the parameter which can affect performance of DSSC was investigated.

Structure and Morphology of Sol-Gel Nanocrystalline TiO2 Films Coated on Glass Substrates

2010 ◽  
Vol 434-435 ◽  
pp. 565-567
Author(s):  
G.J. Ji ◽  
Zhi Ming Shi ◽  
G. Zhao
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Rutile Phase ◽  
Dip Coating ◽  
Tio2 Films ◽  
Nanocrystalline Tio2 ◽  
Doped Tio2 ◽  
Glass Substrates ◽  
Dip Coating Technique

The Ce3+-doped and undoped nanocrystalline TiO2 films were prepared on glass substrates surface by sol-gel dip coating technique. The crystal structure and surface morphology of TiO2 films were characterized by means of X-ray diffractometer (XRD), transmission electron microscopy (TEM) and atomic force microscope (AFM). The results indicated that the Ce3+-doped TiO2 films were solely composed of the anatase phase whereas in the undoped films small amount of the rutile phase of TiO2 were present. The average crystallite size of the undoped TiO2 films was about 30nm and was decreased with Ce3+-doping in the TiO2 films. Moreover, the grains distributed more uniform and the surface roughness was smaller in the Ce3+-doped TiO2 films than in the undoped one. The action mechanism of Ce3+-doping inhibits the crystallization of the rutile phase and decreases the anatase granularity of TiO2 films is associated with its physicochemical properties, as well as ionic diffusion and valance change of Ce3+ to Ce4+ in the sintering process.

STRUCTURAL TRANSITION OF NANOCRYSTALLINE TiO2

2011 ◽  
Vol 10 (01n02) ◽  
pp. 59-63 ◽  
Author(s):  
MANORANJAN KAR ◽  
N. RAMA KRISHNAN ◽  
INDRAJIT TALUKDAR ◽  
K. ACHARYYA
Keyword(s):  
Crystallite Size ◽  
Bulk Material ◽  
Anatase Phase ◽  
Average Crystallite Size ◽  
Rutile Phase ◽  
High Energy ◽  
Nanocrystalline Tio2 ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Xrd Patterns

Nanocrystalline TiO 2 sample was prepared by high-energy ball mill method. A known quantity of anatase phase- TiO 2 was milled for 83 h in air. The samples were collected at intervals of 5 h of milling. The XRD patterns were recorded for all the samples. The crystal structure changed from anatase phase for bulk material to rutile-rich phase for nanocrystalline material. Nanocrystalline TiO 2, which is a mixture of anatase, rutile, and srilankite phase, was prepared by milling for 60 h. The XRD pattern of unmilled anatase phase of TiO 2 could be refined with I41/amd space group. The crystallite size of the TiO 2 was found to decrease with milling time upto 50 h and then the size of rutile phase increases while the sizes of anatase and srilankite phases remain constant upto 60 h of milling. After 60 h, the sizes of all the phases remain constant. The average crystallite size for rutile phase is found to be 12 nm after 60 h of milling.

scholarly journals An Amalgam of Mg-Doped TiO2 Nanoparticles Prepared by Sol-Gel Method for Effective Antimicrobial and Photocatalytic Activity

2021 ◽  
Author(s):  
N NITHYA ◽  
S Gopi ◽  
G Bhoopathi
Keyword(s):  
Crystallite Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Gram Positive ◽  
Tem Analysis ◽  
Gram Negative ◽  
Gel Method ◽  
Sol Gel Method ◽  
And Shifts

Abstract In this study, undoped and Magnesium doped TiO2 nanoparticles (Mg-TiO2 NPs) were successfully synthesized via a simple sol-gel method cost-effectively. The prepared Mg- TiO2 NPs were characterized by UV-Vis, FTIR, PL, XRD, FESEM, TEM, and EDAX. UV – Visible Spectroscopy showed that an increase in the optical bandgap concerning the concentration of dopant Mg increases. The bandgap values were found to be 3.57-3.54 eV. FTIR spectra showed that the presence of the characteristic stretching and bending vibrational band of Ti – O bonding at 468 cm-1 and shifts in vibrational bands were observed for Mg-TiO2 NPs. PL spectra of Mg- TiO2 NPs at different concentrations exhibit a strong UV emission band. X-ray diffraction confirmed the formation of the tetragonal anatase phase. The average crystallite size of prepared samples was found to be 22-19 nm. The average crystallite size of Mg- TiO2 NPs decreases with increasing the concentration of dopant Mg. The FESEM and TEM analysis confirmed that the spherical morphology for both TiO2 and Mg-TiO2 NPs. SAED pattern confirms the crystalline nature of prepared samples. EDAX spectra confirm the presence of Ti, O, and Mg and confirm that Mg2+ ions are present in the TiO2 lattices. The prepared samples were investigated against gram-positive (B. subtilis and S. aureus) and gram-negative (P. eugenia and K. Pneumonia) bacteria. The prepared samples showed potent antibacterial activity against gram-negative bacteria than the gram-positive bacteria. The prepared samples show the excellent photocatalytic degradation for Methylene blue.

The effect of the withdrawal speed on properties of nickel oxide thin films

2019 ◽  
Vol 234 (10) ◽  
pp. 647-655
Author(s):  
Zohra Nazir Kayani ◽  
Atiqa Aslam ◽  
Rabia Ishaque ◽  
Syeda Nosheen Zahra ◽  
Hifza Hanif ◽  
...  
Keyword(s):  
Thin Films ◽  
Nickel Oxide ◽  
Band Gap ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Dip Coating ◽  
Oxide Thin Films ◽  
Withdrawal Speed ◽  
Sem Micrograph ◽  
Nickel Oxide Thin Films

Abstract Nickel oxide thin films have been prepared by sol-gel dip-coating technique on glass substrate. It is shown that nickel oxide thin films have poly crystalline nature. Nickel oxide thin films exhibit high transmission (39–85%) in the wavelength range of 400–900 nm, strong absorption between 300 and 400 nm wavelengths and decrease of band gap values are in the range 3.69–3.27 eV with increase of withdrawal speed. High band gap at low withdrawal speed is because of the small average crystallite size, which decreases with increase in withdrawal speed. The SEM micrograph shows cubic crystallites and surface of thin films become dense, smooth and homogeneous with an increase in withdrawal speed. Assessment of nickel oxide deposition conditions provides gateway for effective and cheap solar cells.

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.

Synthesis, characterization, and photocatalytic activity of silver and zinc co-doped TiO2 nanoparticle for photodegradation of methyl orange dye in aqueous solution

2019 ◽  
Vol 97 (9) ◽  
pp. 642-650 ◽  
Author(s):  
Gabriel O. Oladipo ◽  
Akinola K. Akinlabi ◽  
Samson O. Alayande ◽  
Titus A.M. Msagati ◽  
Hlengilizwe H. Nyoni ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Pore Size ◽  
Average Pore Size ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Rutile Phase ◽  
Absorption Bands ◽  
Average Pore ◽  
Methyl Orange Dye ◽  
Co Doped

In this study, TiO2 nanocrystals, 1 mol% Ag-doped TiO2, and 1 mol% Ag and 0.6 mol% Zn co-doped TiO2 powders were synthesized by the sol–gel route. Their photocatalytic activities on methyl orange dye under visible irradiation were investigated. The powders were characterized by X-ray diffraction (XRD), UV–visible spectroscopy (UV–vis), Brunauer–Emmett–Teller (BET), and Fourier transform infrared spectroscopy (FTIR). The XRD results revealed the presence of a rutile phase with an average crystallite size of 9 and 11 nm. The UV–vis spectra showed a red-shift towards a longer wavelength with the corresponding decrease in band gap from 2.9 to 2.5 eV. The BET surface areas of the nanoparticles ranged from 4.7 to 11.8 m2 g−1 with an average pore size between 18.9 and 56.6 nm. The Ag-doped TiO2 has the largest surface area of 11.8 m2 g−1, whereas the Ag–Zn co-doped TiO2 was found to have the highest pore size and volume. The absorption bands at 750–500 cm−1 were attributed to the –O–Ti–O– bond in the TiO2 lattice. The photocatalytic efficiency was highest at an optimum pH of 4.1 for Ag–Zn co-doped TiO2. The results confirmed that Ag-doped and Ag–Zn co-doped TiO2 were more effective than pure TiO2. The kinetic data were fitted into a pseudo first-order equation using a Langmuir–Hinshelwood kinetic model.

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