scholarly journals Photodegradation of Methylene Blue by TiO2-Fe3O4-Bentonite Magnetic Nanocomposite

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Wei Chen ◽  
Hongyao Xiao ◽  
Hang Xu ◽  
Tonggang Ding ◽  
Yanmei Gu
Keyword(s):  
Methylene Blue ◽  
Aqueous Suspension ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Nitrogen Atmosphere ◽  
Morphological Observation ◽  
X Ray Diffraction ◽  
Uv Illumination ◽  
Coprecipitation Technique ◽  
Good Photocatalytic Performance

Fe3O4-bentonite nanoparticles have been prepared by a coprecipitation technique under a nitrogen atmosphere. An aqueous suspension of bentonite was first modified with FeCl2and FeCl3. TiO2was then loaded onto the surface of theFe3O4-bentonite by a sol-gel method. After sufficient drying, the colloidal solution was placed in a muffle furnace at 773 K to obtain theTiO2-Fe3O4-bentonite composite. The material has been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and vibrating sample magnetometry (VSM). Morphological observation showed thatFe3O4and TiO2nanoparticles had been adsorbed on the surface of bentonite nanoneedles. The material was then applied for the photodegradation of the azo dye methylene blue (MB). It was found that the removal efficiency of MB exceeded 90% under UV illumination, and that only a 20% mass loss was incurred after six cycles. The composite material thus showed good photocatalytic performance and recycling properties.

Preparation and Photocatalytic Property of TiO2/NiFe2O4 Composite Photocatalysts

2012 ◽  
Vol 518-523 ◽  
pp. 775-779 ◽  
Author(s):  
Dong Dong Tan ◽  
De Fu Bi ◽  
Peng Hui Shi ◽  
Shi Hong Xu
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Methyl Orange Solution ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Uv Illumination ◽  
Composite Photocatalysts ◽  
Orange Solution

The TiO2/NiFe2O4 (TN) composite nanoparticles with different mass ratios of NiFe2O4 to TiO2 were prepared via sol-gel method. X-ray diffraction was used to characterize the phase structure of TN. The results indicated that adulterating a smidgen of NiFe2O4 into the TiO2 (about 0.1%) can promote the phase transformation of TiO2, however, when the doping amount of NiFe2O4 surpasses 1%, the introduction of NiFe2O4 can inhibit the growth of TiO2 crystal grain and reduce the size of TiO2 crystal grain. The degradation experiment of methyl orange solution under UV illumination (253.7 nm) showed that the content of NiFe2O4 in the TN was higher, the photocatalytic activity of TN was worse, and the 0.1% TiO2/NiFe2O4 calcined at 400 °C presented the best photocatalytic activity.

Structural, Magnetic and Dielectric Analysis of Higher Magnetic Mn Doped Zn-Cr Oxide Nanoparticles

2021 ◽  
Vol 9 (VI) ◽  
pp. 95-102
Author(s):  
S. D. Balsure
Keyword(s):  
Type Strain ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Xrd Analysis ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Microstructural Parameters ◽  
Auto Combustion ◽  
Mn Doped ◽  
Combustion Technique

Higher magnetic Mn doped Zn-Cr oxide nanoparticles with general compositional formula MxZn0.95-xCr0.05O have been synthesized by using sol-gel auto combustion technique. Room temperature X-ray diffraction (XRD) technique has been employed to study the structural and microstructural parameters of the as-prepared samples. XRD analysis confirms the phase purity and hexagonal wurtzite structure of all the samples. Replacement of Zn2+ ions by Mn2+ ions shifts peak positions slightly towards the lower angles which in turn expands the lattice lengths ‘a’ from 3.2487 to 3.2528 Å and ‘c’ from 5.2043 to 5.2118 Å. Crystallite size obtained from Scherrer equation was confirmed by Williamson – Hall (W-H) and size – strain plot methods (SSP). Both W-H and SSP methods reveals the tensile type strain for undoped sample and comprehensive type strain for Mn2+ doped samples. Magnetic properties were investigated by using vibrating sample magnetometer. Diluted ferromagnetic behaviour is observed for all the samples and saturation magnetization (MS) increases from 0.0514 to 0.1163 emu/gm. Two-probe technique was employed to understand the dielectric behaviour of the samples as a function of frequency. At lower frequency region, both dielectric constant () and dielectric loss tangent (tan ) shows higher values and decreases with the increasing applied frequency.

scholarly journals Effect of Re and Tm-site on morphology structure and optical band gap of ReTmO3 (Re: La, Ce, Nd, Gd, Dy, Y and Tm: Fe, Cr) prepared by sol-gel method

2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Auto Combustion ◽  
Uv Visible

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.

ZnO-SiO2/Laponite Photocatalyst: Kinetic Study on Photocatalytic Decolorization of Methylene Blue

2014 ◽  
Vol 896 ◽  
pp. 541-544
Author(s):  
Is Fatimah ◽  
N. Nunani Yuyun
Keyword(s):  
Methylene Blue ◽  
Energy Dispersive Spectrometry ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photocatalytic Decolorization ◽  
Uv Visible ◽  
Gel Preparation ◽  
Adsorption Desorption

ZnO-SiO2/Laponite was prepared by sol-gel preparation procedure consit of SiO2 pillarization to laponite followed by ZnO dispersion by using zinc acetate as precursor. The obtained material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), diffuse reflectance UV-Visible (DRUV-Vis) and N2 adsorption-desorption analysis. The photocatalytic performance of the amterial in methylene blue decolorization was also investigated. Compared with ZnO-SiO2 nanoparticles, it is concluded that ZnO-SiO2/Laponite possess higher photocatalytic activity which obey Temkin isotherm model.

scholarly journals A Novel Approach for Accelerated Fabrication of Calcium Hydroxyapatite Thin Films

2019 ◽  
Vol 25 (4) ◽  
pp. 365-368
Author(s):  
Pranas USINSKAS ◽  
Živilė STANKEVIČIŪTĖ ◽  
Gediminas NIAURA ◽  
Justinas ČEPONKUS ◽  
Aivaras KAREIVA
Keyword(s):  
Sol Gel ◽  
Calcium Hydroxyapatite ◽  
Xrd Analysis ◽  
Dip Coating ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Angle Measurements ◽  
Novel Approach ◽  
Contact Angle Measurements ◽  
Dip Coating Technique

In this study we demonstrate, that sol–gel route is suitable to quicker obtain calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp) coatings on crystalline Si substrate by modified dip-coating technique. The substrate was dip-coated by precursor and dried for 10 minutes at 200 °C with following cooling using the heating block for 110 min and annealing at 650 °C. Ethylendiamintetraacetic acid and 1,2-ethandiol, and triethanolamine and polyvinyl alcohol were used as complexing agents and as gel network forming agents, respectively. The obtained coatings were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), FTIR spectroscopy and contact angle measurements (CAM).

Formation of Cobalt Doped Zinc Oxide Photocatalyst for Methyl Orange Degradation

2017 ◽  
Vol 264 ◽  
pp. 211-214 ◽  
Author(s):  
Farah Iddayu Abu Bakar ◽  
Katerina Anak Birang ◽  
Mohd Azam Mohd Adnan ◽  
Jeefferie Abd Razak ◽  
Syahriza Ismail
Keyword(s):  
Zinc Oxide ◽  
Methyl Orange ◽  
Sol Gel ◽  
Morphological Observation ◽  
X Ray Diffraction ◽  
Methyl Orange Degradation ◽  
Zno Nanostructure ◽  
Dopant Level ◽  
And Performance ◽  
Co Doped

The formation of cobalt (Co) doped zinc oxide (ZnO) as photocatalyst for photodegradation of methyl orange dye was investigated. The ZnO photocatalyst was produced with different concentration of Co by using sol gel method. The hexagonal wurtzite and zincite structure were successfully formed through this method. The morphological observation of nanorod and nanodisk structure formed was done by Field Emission Scanning Electron Microscope (FESEM). While, the structural properties of Co doped ZnO were identified by X-ray Diffraction (XRD) and Raman spectroscopy. The degradation performance of methyl orange was assessed and performance of photocatalytic activity was correlated to the amount of dopant level and oxygen vacancy of photocatalyst. There is an optimum amount of Co that can be doped into ZnO nanostructure in order to provide better degradation of methyl orange.

Effect of Iron (III)-Doping on the Photocatalytic Activity of Titanium Dioxide Catalysts for Methylene Blue Degradation

2011 ◽  
Vol 117-119 ◽  
pp. 1088-1091
Author(s):  
Wen Churng Lin ◽  
Rui Liu ◽  
Wein Duo Yang
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Effective Means ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Bet Specific Surface Area ◽  
Vis Spectroscopy

Iron-doped TiO2 photocatalyst powders were prepared by the sol–gel method and characterized by Brunauer–Emmett–Teller (BET)-specific surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Ultraviolet–Visible (UV-Vis) spectroscopy. Fe3+ doping in the TiO2 decreases the crystal grain size, increases the specific surface areas of powders, extends the absorption to visible light regions (400~500 nm), and lowers the photocatalytic activity for methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB in water was investigated as a function of the Fe3+ content in TiO2. It was found that under the irradiation of visible light, a small amount of Fe3+ dopant in TiO22 powders could obviously enhance the photocatalytic activity. When the Fe3+ content was in the range of 0.03–0.1 mol%, the photocatalytic activity of the samples was higher than that of undoped TiO2. Appropriate content of Fe-doping is an effective means to improve the photocatalytic activity of TiO2 for MB degradation under visible light irradiation.

Synthesis and Characterization of Pd/Ag/SiO2 Nano-Composite Materials

2017 ◽  
Vol 726 ◽  
pp. 204-209 ◽  
Author(s):  
Jing Yang ◽  
Bao Song Li ◽  
Zhi Tong ◽  
Rui Hua Mu
Keyword(s):  
Zeta Potential ◽  
Size Distribution ◽  
Sol Gel ◽  
Linear Structure ◽  
Nitrogen Atmosphere ◽  
Molar Ratio ◽  
Powder Materials ◽  
X Ray Diffraction ◽  
Silica Network

Pd/Ag/SiO2 sols and powder materials were prepared by adding AgNO3 and Pd (NO3)2·2H2O into a methyl-modified silica sol. Tetraethylorthosilicate and methyltriethoxysilane were used as the silica precursor for the sol-gel reaction. The obtained SiO2 sols and powder materials were characterized by sol particle size distribution, zeta potential analysis, UV-Vis spectra, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurement. It was found that most of the particle sizes of the prepared Pd/Ag/SiO2 sols are about 2~10 nm with narrow size distribution. The zeta potential of Pd/Ag/SiO2 sol with Pd/Ag molar ratio of 7.5/2.5 presents the highest value. The FTIR analysis substantiates that the Si-CH3 groups exist in the silica network and the formed Pd/Ag/SiO2 sol particles possess linear structure. XRD characterization indicates that the Pd2+ and Ag+ in the Pd/Ag/SiO2 materials had be reduced to Pd0 and Ag0, respectively, after annealed in a nitrogen atmosphere at 350°C.

Synthesis of Ultra-Thin Superhydrophilic Titanium Oxide Film and its Effects on the Capillary of Microchannels

2010 ◽  
Author(s):  
Min Zhang ◽  
Bo Zhang ◽  
Tianhong Cui
Keyword(s):  
Titanium Oxide ◽  
Sol Gel ◽  
Nitrogen Atmosphere ◽  
Tio2 Films ◽  
Titanium Tetraisopropoxide ◽  
X Ray Diffraction ◽  
Before And After ◽  
Potential Applications ◽  
Temperature Surface

Ultra-thin superhydrophilic titanium oxide films were fabricated on silicon microchannels by an in situ reaction sol-gel method using titanium tetraisopropoxide as a starting material.. By changing the concentration of water in ethanol and reaction time, the thickness of synthesized TiO2 films can be controlled from around 10 nm to 80 nm. The contact angle of as-synthesized TiO2 films on flat silicon is around 20° and can be further decreased to zero by calcination at 700 °C in nitrogen atmosphere. X-ray diffraction spectra show the microstructure of the TiO2 films changed gradually from amorphous to anatase with the increase of calcination temperature. Surface morphology of the film before and after calcination also shows that a smoother coating with crystal structure was obtained by heat treatment. The flow velocity in the TiO2 coated channel reached around 0.03 m/s, almost ten times of that in PDDA/PSS coated channel and 4 times of that in SiO2 coated one. The ultra-thin superhydrophilic TiO2 films fabricated by this method show the ability to strongly increase the wettability of microchannels without affecting the morphology of the sidewall of the channels, indicating potential applications to biomolecule analysis and surface tension driven microfluidic systems.

Photoconversion of CO2 using copper-modified titanium dioxide nanoparticles

2011 ◽  
Vol 76 (11) ◽  
pp. 1335-1346 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao
Keyword(s):  
Titanium Dioxide ◽  
Photoelectron Spectroscopy ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Chemical Properties ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Illumination ◽  
One Step

A series of copper-modified titanium dioxide (Cu/TiO2) nanoparticles were synthesized via one-step sol-gel method. The crystal structure and chemical properties were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Cu/TiO2nanoparticles were applied to CO2photoconversion and the yield of formaldehyde was used to evaluate the photocatalytic performance. The optimum amount of copper modifying was 0.6 wt.% and the yield of formaldehyde was 946 μmol/gcatunder UV illumination for 6 h. 20 wt.% Cu/TiO2also performed a high photocatalytic activity, which yielded 433 μmol/gcatformaldehyde under UV illumination for 6 h.

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