Acetaldehyde Photocatalytic Decomposition over Nanostructured TiO2 Sol-Gel Catalysts

2010 ◽  
Vol 1279 ◽  
Author(s):  
S. Castillo ◽  
R. Camposeco ◽  
R. Carrera ◽  
M. Mujica ◽  
P.Del Ángel ◽  
...  
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Photocatalytic Decomposition ◽  
Test Results ◽  
Rietveld Refinements ◽  
Confined Spaces ◽  
Tio2 Sol ◽  
Uv Lamp ◽  
Organic Gases ◽  
Brookite Phase

AbstractTiO2nanoparticles were synthesized by the Sol-Gel method by using 2-propanol as solvent in acid medium (pH1). The samples were annealed at 200 and 500°C and were characterized by BET, XRD-Rietveld refinements, TEM and FTIR. The activity was evaluated by the acetaldehyde photodecomposition in an isolated chamber with an initial concentration of contaminant of 300 ppmv with oxygen (2%) assisted with a 365-nm UV lamp. The test results were compared with those obtained with a commercial catalyst (P25). Improved photoactivity (≍100 % of acetaldehyde in 150 min) was obtained with catalysts annealed at 200°C (TiO2-P-200°C), that showed nanoparticles (≍7 nm) and abundant anatase phase (≍ 63 %) coexist with the brookite phase (≍ 37 %), as well as irregular equiaxial morphology. The samples annealed at 500°C (TiO2-P-500°C), showed an increment in nanoparticles (≍22 nm), different ratio and phase composition (anatase-brookite-rutile), and therefore less activity (≍80 %). This high activity could be explained by the special ratio of anatase-brookite and the dimension of nanometric crystal size. The aforementioned characteristics could be useful in the degradation of reactive organic gases like acetaldehyde either in confined spaces or in the open air.

scholarly journals Primary Colors Red, Yellow, and Blue Use as Self-Cleaning Paints with Layer of Titanium Dioxide

2019 ◽  
Vol 16 (4) ◽  
pp. 0903
Author(s):  
Suma H. Al-Shaikh Hussin
Keyword(s):  
Titanium Dioxide ◽  
Anatase Phase ◽  
Sol Gel ◽  
Morphological Properties ◽  
Yellow Color ◽  
Nano Coating ◽  
Average Grain Size ◽  
Tio2 Sol ◽  
Self Cleaning ◽  
Oil Paints

Transparent nano- coating was prepared by Sol-Gel method from titanium dioxide TiO2 which has the ability to self-cleaning coating used for hospitals, laboratories, and places requiring permanent sterilization. Three primary colors are selected (red, blue, and yellow) as preliminary study to the effect of these colors on the nano-coating. Three traditional oil paints color were used as base, then coated by a layer of TiO2-Sol and deposited on the paints. The optical properties of TiO2-Sol were measured; the maximum absorption wavelength at (λmax=387 nm), the refractive index (n=1.4423) and the energy band gap (Eg=3.2 eV). The structure properties found by X-ray diffraction of TiO2-Sol illustrated that TiO2-Sol is polycrystalline nanoparticle have anatase phase also the morphological properties measured by Scanning Electron Microscopy (SEM) obetained the average grain size of TiO2-Sol was (50.427 nm). Self-cleaning properties measured by tensiometer dives. The best color gave the highest response to self-cleaning is the yellow color where the contact angle before exposure to UV ( = 101.47º ,at t = 0 min) and after exposure over time ( = 1.75º ,at t = 50 min), thus the water sheet of the surface and remove all contaminants.

Degradation of Volatile Acetone by a Photocatalytic Reactor with TiO2 Coated Sieve

2010 ◽  
Vol 123-125 ◽  
pp. 919-922
Author(s):  
Chen Yu Chang ◽  
Yao Chuan Lee ◽  
Ching Hsing Lin ◽  
Jyh Wei Lee ◽  
Yu Jie Chang ◽  
...  
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Amorphous Structure ◽  
Tio2 Thin Films ◽  
Sem Images ◽  
Photocatalytic Reactor ◽  
Gel Method ◽  
Sol Gel Method ◽  
Uv Lamp ◽  
Pass Through

The TiO2 thin films were coated on the 100 meshes stainless steel 304 (SS304) sieves by using the sol-gel method followed by a thermal treatment at 200oC. The prepared TiO2-coated sieves were then employed to setup a photocatalytic reactor for evaluating their abilities on the degradation of VOCs (volatile organic compounds). The UV lamp was enveloped with a cylinder TiO2-coated sieve and located in the center of the reactor. A VOCs diffusing tube was applied to yield acetone under water bath. The yielded gaseous acetone was enforced to pass through the TiO2-coated sieves and reacted by photocatalytic reaction. Both the inflow gas and off-gas were monitored by a PID (photoionization detector) sensor for calculating the treat efficiencies under various conditions. The results showed that the amorphous structure was observed on the TiO2 films after sol-gel method, whereas the crystalline anatase phase was found after annealing at 200oC. The SEM images showed that the surface morphology of TiO2 coated SS304 sieves was very similar to that of uncoated sieves, demonstrating a good uniformity and thin thickness of the sol-gel coating method derived in this work. It was observed that most volatile acetone (almost 100%) was removed after treated with the designed photocatalytic reactor under a high fed flow rate (0.5- 2.0 l/min). As compared with the control experiments (UV OFF test), the adequate photocatalytic abilities of this developed TiO2 coated sieves were demonstrated. With the advantages of high contacting area with VOCs, low headloss, durable substrate and easy maintenance, the TiO2-coated sieves possessed a high potential for applying on the photocatalytic degradation of indoor air pollutants.

scholarly journals Synthesis of anatase nanopowders by sol-gel method and influence of temperatures of calcination to their photocatalitic properties

2015 ◽  
Vol 47 (1) ◽  
pp. 41-49 ◽  
Author(s):  
A. Golubovic ◽  
B. Simovic ◽  
M. Scepanovic ◽  
D. Mijin ◽  
A. Matkovic ◽  
...  
Keyword(s):  
Photocatalytic Performance ◽  
Anatase Phase ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Textile Dye ◽  
Reactive Orange 16 ◽  
Tio2 Nanopowders ◽  
Gel Technique ◽  
Reactive Orange ◽  
Brookite Phase

The titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor, varying the temperature ?f calcination (from 500 to 550?C with the step of 10 ?C). XRPD results have shown that all synthesized nanopowders are dominantly in anatase phase. The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results and added the presence of small amount of highly disordered brookite phase in all samples. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 1.5 and 4.5 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16). The sample calcined at temperature of 510?C showed the best photocatalytic performance.

scholarly journals Effect of Thiourea as a Doping for Nanotitania

2019 ◽  
Vol 1 (2) ◽  
pp. 81-88
Author(s):  
Nabilah Rafidiyah
Keyword(s):  
Particle Size ◽  
Anatase Phase ◽  
Catalyst Activity ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Doped Tio2 ◽  
Photo Catalyst ◽  
Transmission Electron ◽  
Golden Yellow ◽  
Uv Lamp

Sulphur-doped TiO2 samples were prepared by sol gel method using thiourea as sulphur source. The amount of thiourea solutions are 0; 0.5; 1.0; 1.5 and 2 ml, respectively. Sulphur-doped TiO2 was calcinated at 450°C. Sulphur-doped TiO2 and pure TiO2 were characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM). Photo catalyst tests were carried out under sunlight and UV lamp. Based on XRD characterization, the samples are anatase phase. Furthermore, particle size was calculated using Scherrer equation and results of 8.94 and 12.98 nm, respectively for TBT-1.5 and TBT-0.5. TEM characterization showed that particle size of sulphur-doped TiO2 and pure TiO2 are 8.6 and 12.5 nm. Compared to TiO2 without doping, sulphur-doped TiO2 has a better photo catalyst activity for degradation of remazol golden yellow under visible light.

Fe-TiO2 Nanoparticles by Hydrothermal Treatment with Photocatalytic Activity Enhancement

2014 ◽  
Vol 1024 ◽  
pp. 39-43 ◽  
Author(s):  
Siti Aida Ibrahim ◽  
Srimala Sreekantan
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Treatment ◽  
Anatase Phase ◽  
Sol Gel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Fe Content ◽  
Vis Spectroscopy ◽  
Activity Enhancement ◽  
Brookite Phase

Fe-TiO2nanoparticles with 5-9 nm sizes were prepared by sol gel method subsequently subjected to hydrothermal treatment at 150°C for 6 h. Titanium (IV) isopropoxide and iron (III) nitrate nonahydrate were used as precursor. The morphology, structure and composition of the Fe-TiO2were investigated by X-ray diffraction (XRD), Transmission emission microscopy (TEM) and UV-vis spectroscopy (UV-vis). XRD analysis revealed the prepared samples was dominated with anatase phase and a trace of brookite phase. The TiO2crystallite size was reduced as Fe content was increased. Compared with the pure TiO2nanoparticles, the Fe-TiO2nanoparticles exhibited higher photocatalytic activity in decolorizing methyl orange into non-toxic inorganic products under UV irradiation.

Glass Fibers Covered with TiO2 Thin Films by Sol-Gel Method as a Photocatalyst Reactor to Degradation Toluene

2009 ◽  
Vol 79-82 ◽  
pp. 927-930 ◽  
Author(s):  
Ching Hsing Lin ◽  
Chen Yu Chang ◽  
Yu Jie Chang ◽  
Jyh Wei Lee ◽  
Mei Yin Hwa ◽  
...  
Keyword(s):  
Thin Films ◽  
Glass Fibers ◽  
Sol Gel ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Photocatalytic Ability ◽  
Toluene Concentration ◽  
Tio2 Sol ◽  
Uv Lamp

TiO2 thin films obtained by sol-gel and dipping deposition on glass fibers substrates followed by thermal treatment was used in this works. In an attempt to understand the structure and the morphology of TiO2 sol-gel thin films, analysis by X-ray diffraction (XRD) and scanning electron microscopy (SEM) are reported. Degradation of toluene under 365 nm light illumination was conducted to evaluate the photocatalytic ability of the TiO2 thin films. A special design of glass reactor allowed the UV lamp to be located in the center of the reactor. The photocatalyst reactor was then filled with TiO2 thin films/glass fibers substrates to exams the photocatalysis of toluene vapor ranged from 10 to 1,000 ppmv. Toluene depletion was sampled by gas chromatography (GC). The results showed that the photocatalytic performance of the reactor had high toluene depletion efficiency of 99.9% under 20 ppmv, and the efficiency decreased when toluene concentration were 100 and 1,000 ppmv. The improvement of the photocatalytic activity was ascribed to the fibers-based reactor provides a significantly huge surface area of the TiO2 thin films. These results will be useful and assist engineers to design photocatalyst reactors for the VOCs removal.

scholarly journals Thermal study of the anatase–rutile structural transitions in sol-gel synthesized titanium dioxide powders

2005 ◽  
Vol 70 (4) ◽  
pp. 675-679 ◽  
Author(s):  
Farias de ◽  
Cecilia Silva ◽  
Thomaz Restivo
Keyword(s):  
Titanium Dioxide ◽  
Crystallite Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Metal Chlorides ◽  
Sol Gel Process ◽  
Dta Analysis ◽  
Diffraction Patterns ◽  
Brookite Phase

Titanium dioxide powders were synthesized by the sol?gel process using titanium tetrabutoxide as the precursor. The syntheses were performed in saturated aqueous solutions of KCl, CaCl2, NiCl2, CoCl2 and MnCl2, and in dimethylformamaide (DMF) and dimethylsulfoxide (DMSO) solutions. The obtained X-ray diffraction patterns show that all samples were crystalline (anatase phase) with some minor amounts of a brookite phase. It is worth noting that the anatase phase was obtained independent of any previous or further treatment of the synthesized powder, such as hydrothermal or heat treatment. For the titanium dioxide powders synthesized in saturated aqueous solution of metal chlorides (mean crystallite size = 11 nm), the anatase?rutile transition occurred in the range 455?570 ?C, depending on the considered sample, as verified by DTA analysis. In the powders synthesized in DMF or DMSO solutions (means crystallite size = 6 nm), the same structural transition occurred at 485 ?C.

scholarly journals Pengaruh Ethanolamina (MEA) dalam Pembentukan TiO2 dari Bahan Awal Ti Butoksida

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Rika Rahayu ◽  
◽  
Posman Manurung ◽  
Yanti Yulianti ◽  
◽  
...  
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tem Characterization ◽  
Transmission Electron ◽  
Imagej Software ◽  
Uv Lamps ◽  
Brookite Phase

Titanium dioxide has been prepared through the sol gel method using the addition of ethanolamine. The research was conducted to study the effect of MEA on the formation of TiO2. The amount of MEA was varied to 0; 0.5; 1; 1.5; and 2 ml respectively. The samples were calcined at a temperature of 500 ºC. TiO2was characterized using X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and photocatalyst tests using UV lamps. The XRD characterization results showed that in the A sample an anatase phase was formed whereas in the Csample an anatase phase and a brookite phase were formed. The resultof TEM characterization using ImageJ software show that the particle size of TiO2 is26,1 nm, respectively. The results of the characterization of the fastest photocatalyst catalyst test occurred in sample C which the variation of MEA is 1 ml.

scholarly journals Analysis of Polymorphic Nanocrystals ofTiO2by X-Ray Rietveld Refinement and High-Resolution Transmission Electron Microscopy: Acetaldehyde Decomposition

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
R. Carrera ◽  
N. Castillo ◽  
E. Arce ◽  
A. L. Vázquez ◽  
M. Moran-Pineda ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rietveld Refinement ◽  
Sol Gel ◽  
Photocatalytic Decomposition ◽  
X Ray ◽  
Transmission Electron ◽  
Treated Sample ◽  
Crystallite Sizes ◽  
Brookite Phase ◽  
Small Crystallite

In this work,TiO2nanocrystals were synthesized by the sol-gel method. These materials were annealed at 200 and500∘C; and characterized by the XRD-Rietveld refinement; and by BET and TEM. As for the low-temperature-treated sample (200∘C), nanocrystals with small crystallite sizes (7 nm) and high abundance of anatase, coexisting with the brookite phase, were obtained. Meanwhile, the sample annealed at500∘C showed an increased crystallite size (22 nm) and an important polymorphic increment. The sample annealed at200∘C showed a high activity in the photocatalytic decomposition of acetaldehyde.

Synthesis, Structural, Optical, and Magnetic Properties of Fe Doped TiO2 along with Different Concentration

2013 ◽  
Vol 665 ◽  
pp. 118-126
Author(s):  
Kirit S. Siddhapara ◽  
D.V. Shah
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Photo Luminescence ◽  
Red Shift ◽  
Structural And Optical Properties ◽  
Xrd Pattern ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Gel Technique ◽  
Brookite Phase

Nanocrystalline Fe-doped TiO2 was prepared by Sol-Gel technique, which was followed by freeze at-30°C temperature for 12hrs. The obtained Gel was thermally treated at 200,400,600 and 800°C. X-ray Powder Diffraction (XRD), Scanning Electron microscopy (SEM), UV-Vis Spectroscopy, Photo luminescence (PL) and EDAX was used to study its Structural and Optical properties. All Fe-doped TiO2 nanostructures show an appearance of Red shift relative to the bulk TiO2. The XRD pattern show the coexistence of major anatase phase and minor brookite phase for samples treated up to 600°C. Whereas at 800°C rutile is the only phase observed. All Fe doped TiO2 nanostructures show an appearance of Red shift relative to bulk undoped TiO2. The magnetic property by Gouy Balance of Fe doped TiO2 exhibit Peramagnetism at room temperature.

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