The Preparation of TiO2 Film Loaded on Fiberglass Mesh and the Experimental Study on Its Photocatalytic Properties

2010 ◽  
Vol 150-151 ◽  
pp. 1421-1424 ◽  
Author(s):  
Man Wang ◽  
Wei Chen ◽  
Cheng Liu

The TiO2 film loaded on fiberglass mesh was prepared by sol-gel method using butyl titanate as raw material, and the catalyst was characterized by scanning electron microscopy (SEM) and X-ray diffraction(XRD).The catalyst surface of loaded TiO2 can obviously observe solid particles and agglomeration to some extent, the crystalline phase was anatase, and no rutile was observed, the average particle diameter of TiO2 was 40nm,Under the ultraviolet light UV-C irradiation, the photocatalytic oxidation experiments of humic acid solution was conducted. The results showed that the prepared photocatalyst has a high photocatalytic activity, the UV254 degradation rate of humic acid solution in 60min reached 96.9%, but the degradation rate of TOC is only 57.3%, indicating that the organisms in humic acid can not be completely mineralized in photocatalytic oxidation process.

2013 ◽  
Vol 804 ◽  
pp. 62-66
Author(s):  
Hui Luo

Anodic oxidation processing titanium foil in an aqueous solution of hydrofluoric acid+ glacial acetic acid+polyethylene glycol constant pressure, Synthesized by high-density ordered TiO2nanotube arrays. Calculate the degradation rate of chloramine phosphorus, TiO2nanotubes catalytic performance test.The use of scanning electron microscopy (SEM) and X-ray diffraction (XRD) to characterize the morphology and structure of the nanotubes, Visits oxidation time on the morphology and size of the nanotube arrays, mapping and analysis of current - time curve. An average particle diameter d of the sample may be calculated the strongest diffraction peak of the plane FWHM ,So chloramine phosphorus selection of organic phosphorus drugs for the photocatalytic degradation object, Molybdenum blue spectrophotometry measured and calculated degradation rate, Study of heat treatment temperature and anodizing time photocatalytic degradation, And the sol - gel prepared TiO2 thin film and photocatalytic comparative experiments.


2019 ◽  
Vol 15 ◽  
pp. 6056-6077
Author(s):  
Ahmed Hassan Ibrahim ◽  
Yehia Mohammed Abbas ◽  
Shehab Esmail Mohammed ◽  
Ahmed Bakry Mansour

In this work, we studied the structural and magnetic properties of multiferroic La1-xYxFeO3 perovskites, (x= 0.0, 0.05, 0.1, 0.15, 0.25 and 0.3) which synthesized through Sol-gel auto-combustion technique using a citric acid as a fuel. The room temperature synchrotron X-ray diffraction (XRD) analysis revealed that the all the synthesized samples consisted of the polycrystalline orthorhombic structure perovskites(space group pnma), and tolerance factor confirmed the phase stability of the prepared perovskite system.The Williamson-Hall plot based on synchrotron XRD data were employed to estimate the average particle diameter and varies from 18 nmto 27.8 nm.For a deeper insight of the crystal structure, high resolution transmission microscopy imaging (HRTEM) was performed. The estimated values of crystallite size from HRTEM and synchrotron XRD data were coincident. Many of crystallographic parameters and electron density measurements were calculated by Rietveld refinement of synchrotron XRD data. La1-xYxFeO3 perovskite crystalsarecanted antiferromagnets with a weak ferromagnetism in room temperature.The magnetic properties were gotten through analyzing the magnetization versus temperature M(T) and M(H) hysteresis loop which characterized by a vibrating sample magnetometer (VSM). The molecular structure showed the decrease of the tilting of the octahedra <FeO6> with increasing Y content trying to strengthen the ferromagnetic character. Selected Area Electron Diffraction (SAED) patterns of the investigated samples exhibited spotty ring patterns,confirming the polycrystalline character.The orthoferrite La1-xYxFeO3 crystalsare a promising candidate for optical device applications in broad temperature range and high power system.


2000 ◽  
Author(s):  
J. Jiang ◽  
Y. Hao ◽  
Y.-X. Tao

Abstract To improve the understanding of convective melting of packed solid particles in a fluid, an experimental investigation is conducted to study the melting characteristics of a packed bed by unmasking the buoyancy forces due to the density difference between the melt and solid particles. A close-loop apparatus, named the particle-melting-in-flow (PMF) module, is designed to allow a steady state liquid flow under a specified temperature. The module is on board NASA’s KC-135 reduced gravity aircraft for the experiments. In the test module, water is used as the fluid, and ice particles are fed to the test section at the beginning of the test. As the liquid flows though the bed, the solid grains melt. A perforate plate, through which liquid can flow while the ice particles are retained, bounds the downstream of the packed bed. From the digital video images the local packed bed thickness is measured under control flow rate, and the melting rate is determined. The temperature distribution along the horizontal direction and vertical direction is measured using 19 thermocouples. An infrared camera is mounted to record the local temperature variation between liquid and solid. The melting rates are presented as a function of upstream flow velocity, temperature and initial average particle size of the packed bed. It is found that the melting rate is influenced mainly by the ratio of the Reynolds number (Re, based on the initial particle diameter) to the square of the Froud number (Fr), and me Stefan number (Ste). In general, the dimensionless melting rate decreases as Re/Fr2 increases and increases as Ste increases. With the absence of gravity, i.e., Froud number approaches infinity, a maximum melting rate can be achieved for otherwise the same test conditions. The increase in the melting rate with the increase in Stephan number also becomes more pronounced under the zero gravity condition.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Niu Niu ◽  
Shu-Hua Teng ◽  
Hua-Jian Zhou ◽  
Hai-Sheng Qian

Chitosan-silica (CS-SiO2) hybrid microspheres were prepared through the combined process of sol-gel and emulsification-crosslinking. Their composition, morphology, in vitro bioactivity, and drug release behavior were investigated. The results showed that, when 20 wt% SiO2 was incorporated, the as-prepared CS-SiO2 hybrid microspheres exhibited a regular spherical shape, a high dispersity, and a uniform microstructure. Their average particle diameter was determined to be about 24.0 μm. The in situ deposited inorganic phase of the hybrid microspheres was identified as amorphous SiO2, and its actual content was determined by the TG analysis. As compared with the pure chitosan microspheres, the CS-SiO2 hybrid microspheres displayed a greatly improved in vitro bioactivity. Vancomycin hydrochloride (VH) was selected as a model drug. It was demonstrated that the CS-SiO2 hybrid microspheres presented a good capacity for both loading and sustained release of VH. Moreover, the increase of the SiO2 content efficiently slowed down the drug release rate of the CS-SiO2 hybrid microspheres.


2014 ◽  
Vol 608 ◽  
pp. 164-169
Author(s):  
Peerawas Kongsong ◽  
Lek Sikong ◽  
Sutham Niyomwas ◽  
Vishnu Rachpech

The Fe3+ and N–doped 3SnO2/TiO2 composite thin films and undoped films coated on glass fibers were prepared by sol–gel and dip–coating methods. The films were calcined at 600°C for 2 hour and characterized by XRD, SEM, EDS and XPS. The photocatalytic activity of the coated glass fibers was determined by means of degradation of a methylene blue (MB) solution and humic acid (HA). It was found that the optimized 20N/3SnO2/TiO2composite films exhibit a high photocatalytic activity and HA could be rapidly removed from water. The main factor affecting the HA degradation of 20N/3SnO2/TiO2 films is quantity of glass fibers loading, irradiation power of UV lamp and flow rate of water.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2834
Author(s):  
A.M. Vasconcelos da Silva ◽  
J.M.P.Q. Delgado ◽  
A.S. Guimarães ◽  
W.M.P. Barbosa de Lima ◽  
R. Soares Gomez ◽  
...  

The conformation of a ceramic piece follows the steps of preparing the raw material, molding, lamination, drying, and firing. Drying is a thermodynamic process of heat and mass transfer, with dimensional variations of the product that requires a large amount of energy. Ceramic materials when exposed to non-uniform drying may suffer cracks and deformations, reducing their post-drying quality. Thus, this work aimed to study the drying of industrial ceramic blocks in an oven with forced air circulation. Experiments were carried out to characterize the clay and drying of the ceramic block at temperatures ranging from 50 °C to 100 °C. Results of the chemical, mineralogical, granulometric, differential thermal, and thermogravimetric analysis of the clay, and heating kinetics, mass loss, and dimensional variation of the industrial ceramic block are presented and analyzed in detail. It was found that the clay is basically composed of silica and alumina (≈ 80.96%), with an average particle diameter of 13.36 μm. The study proved that drying at high temperature and low relative humidity of the air generates high rates of mass loss, heating, and volumetric shrinkage in the ceramic product, and high thermo-hydraulic stresses, which cause the appearance and propagation of cracks, gaps, and cleavages, compromising the final quality of the product.


2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Quanjie Wang ◽  
Yanqing Wang ◽  
Baorong Duan ◽  
Mengmeng Zhang

Multiwalled carbon nanotube (MWCNT) enhanced MWCNT/TiO2nanocomposites were synthesized by surface coating of carbon nanotube with mixed phase of anatase and rutile TiO2through a modified sol-gel approach using tetrabutyl titanate as raw material. The morphological structures and physicochemical properties of the nanocomposites were characterized by FT-IR, XRD, DTA-TG, TEM, and UV-Vis spectra. The results show that TiO2nanoparticles with size of around 15 nm are closely attached on the sidewall of MWCNT. The nanocomposites possess good absorption properties not only in the ultraviolet but also in the visible light region. Under irradiation of ultraviolet lamp, the prepared composites have the highest photodegradation efficiency of 83% within 4 hours towards the degradation of Methyl Orange (MO) aqueous solution. The results indicate that the carbon nanotubes supported TiO2nanocomposites exhibit high photocatalytic activity and stability, showing great potentials in the treatment of wastewater.


2011 ◽  
Vol 287-290 ◽  
pp. 1731-1734 ◽  
Author(s):  
Han Sheng Li ◽  
Hang Xu ◽  
Shi Ying Wang ◽  
Ya Lin Pan ◽  
Qin Wu ◽  
...  

Anatase nano-titania (nano-TiO2) was prepared by using a sol-gel process mediated in reverse microemulsion combined with a solvent thermal technique. The results show that the anatase structure appears in the calcination temperature range of 400-510°C, while the transformation of anatase into rutile takes place above 510°C. The average particle size (dP) of the nano-TiO2 increases with the rise of water/Triton X-100 molar ratio (ω) but decreases with the rise of acetyl acetone/n-TBT molar ratio (p) and n-hexanol/Triton X-100 molar ratio (m). The obtained TiO2 particles with a small size have high photocatalytic activity.


2010 ◽  
Vol 105-106 ◽  
pp. 815-818
Author(s):  
Hai Da Liao ◽  
Jin Lie Ma ◽  
Jian Dai

Metatitanic acid was adopted as the raw material to prepare Fe-doped TiO2 nanocrystalline composite particles using suspension polymerization and sol-gel method, which were then characterized with XRD, TEM, TG-DTA and IR, etc.. The results showed the samples were nanocrystal accumulated porous particles, with average particle size of 29nm. Through doping of Fe3+ ion, the photo catalytic activities of particles under Xe lamp were investigated by photodegrading the methyl orange. It was found that, the TiO2 nanocrystal doped with 0.5% Fe3+ ion (accounted as mass fraction) had the highest catalytic activity. The Fe-doped TiO2 nanocrystalline composite particles prepared in this study has high activity, is easy for separation, recovery and reuse.


2013 ◽  
Vol 805-806 ◽  
pp. 247-250
Author(s):  
Zhen Xing Liu ◽  
Xiao An Nie ◽  
Yi Gang Wang

Styrax confusus Hemsl., a promising energy plant, was used as raw material for biodiesel preparation in this paper. The transesterification was catalyzed by magnetic catalyst S2O82--ZrO2/Fe3O4, prepared by chemical co-precipitation method. TEM images indicat that the average particle diameter of magnetic core Fe3O4 and catalyst carrier ZrO2/Fe3O4 are 5-20 nm and 30-50 nm respectively. Because of its unique porous structure the BET surface area could up to 140.75 m2/g. The results show that a best catalytic activity is obtained when the solid catalyst impregnated in 2.5 mol·L-1 (NH4)2S2O8, calcined at 400 °C for 3 h, and a high methyl ester yield could be obtained under the optimal reaction conditions of catalyst amount 4.5 % (wt/wt oil), molar ratio of methanol/oil 6:1, reaction temperature 65 °C and time 2.0 h.


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