scholarly journals Photocatalytic degradation of tartrazine dye using CuO straw-sheaf-like nanostructures

2017 ◽  
Vol 75 (6) ◽  
pp. 1421-1430 ◽  
Author(s):  
Martha Purnachander Rao ◽  
Jerry J. Wu ◽  
Abdullah M. Asiri ◽  
Sambandam Anandan

Straw-sheaf-like CuO nanostructures were fruitfully synthesized using a chemical precipitation approach for the photocatalytic degradation assessment of tartrazine. Phase identification, composition, and morphological outlook of prepared CuO nanostructures were established by X-ray diffraction and scanning electron microscopy analysis. The photocatalytic performance of the synthesized CuO nanostructures was appraised in the presence of visible light and the possible intermediates formed during the photocatalytic degradation were analyzed by gas chromatography–mass spectrometry. A suitable degradation pathway has also been proposed.

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Yang Lu ◽  
Meihuan Yao ◽  
Aiguo Zhou ◽  
Qianku Hu ◽  
Libo Wang

Ti3C2/TiO2/CuO nanocomposites were synthesized via the decomposition of a mixture of Ti3C2 (a novel two-dimensional carbide) and cupric nitrate under an argon atmosphere. The morphology and structures of the obtained samples were characterized. X-ray diffraction and energy dispersive spectrometer analysis indicate that the sample is composed of Ti3C2, anatase-TiO2, and CuO. Scanning electron microscopy images show that CuO and TiO2 nanoparticles were evenly distributed on the surface of Ti3C2. The particles size increased with an increase in the cupric nitrate content. Photocatalytic degradation of methyl orange shows that the Ti3C2/TiO2/CuO nanocomposite has good photocatalytic degradation efficiency. A possible photocatalytic mechanism of the Ti3C2/TiO2/CuO nanocomposites was proposed. The data indicated that CuO and Ti3C2 effectively promote the separation of photoelectrons from vacancies.


2015 ◽  
Vol 68 (6) ◽  
pp. 981 ◽  
Author(s):  
Sara Zamanian ◽  
Ali Nemati Kharat

The catalytic hydroalkoxylation of α,β-unsaturated esters, nitriles, and ethers with aliphatic and aromatic alcohols over pollucite using thermal and microwave-assisted methods was investigated. To study the effect of the alcohol structures on the mechanism of the hydroalkoxylation reaction, different alcohols, such as methanol to butanol, cyclohexanol, phenol, and 2-ethylhexanol were used. The activities of pollucite, in contrast to other basic solids, were scarcely affected by the presence of air and moisture. The correlation between alcohol acidity and reaction activity is discussed. The prepared pollucite was characterized by X‐ray diffraction, volumetric nitrogen adsorption surface area analysis, and CO2 temperature‐programmed desorption. Scanning electron microscopy analysis revealed that the size of the modified nano catalyst particles was under 40 nm.


2020 ◽  
Vol 38 (4A) ◽  
pp. 586-593
Author(s):  
Hayder A. Sallal ◽  
Alla A. Abdul-Hameed ◽  
Farhad. M. Othman

This study describes the preparation and study of the properties of Nano composite particles prepared in a sol-gel method which consists of two materials (Αl2Ο3-MgΟ). The powder was evaluated by x-ray diffraction analysis, scanning electron microscopy analysis (SEM), particle size analysis, and energy dispersive x-ray analysis (EDX) and antibacterial test. The evaluation results of the nanocomposite particles shows a good distribution of the chemical composition between aluminum oxide and magnesium oxide, smoothness in particles  size where it reached to (54.9, 59.8) nm at calcination in (550 0C and 850 0C) respectively, formation of different shapes of nanoparticles and different  phases of the Αl2Ο3 particles (kappa and gamma) and nanopowder have well antibacterial action, Therefore, this reflects the efficiency of the proposed method to manufacture the nanocomposite powder and the possibility of using this powder as a strengthening material for the composite materials and using these composite materials in bio applications, especially in the fabrication of artificial limbs.


2000 ◽  
Vol 14 (25n27) ◽  
pp. 2731-2736 ◽  
Author(s):  
M. BINDI ◽  
F. FUSO ◽  
N. PUCCINI ◽  
E. ARIMONDO ◽  
A. TAMPIERI ◽  
...  

Correctly c-axis oriented HgBa 2 CaCu 2 O 6+δ thin films have been produced on (100) MgO single crystal substrates and characterized. Pulsed laser deposition has been exploited to deposit Hg-free Re-doped precursor which then underwent synthesis in evacuated and sealed quartz tubes. X-ray diffraction pattern of the precursor target shows the expected composition of oxides. Scanning electron microscopy analysis have been performed on the surface of the precursor film. Hg-1212 films have been analyzed by θ-2θ Bragg-Brentano X-ray diffractometry. The patterns show little contributions in composition of Hg-1223 phase. The films exhibit a transition temperature >120 K with zero-resistance at around 115 K.


2012 ◽  
Vol 44 (3) ◽  
pp. 307-321 ◽  
Author(s):  
M.V. Nikolic ◽  
M.P. Slankamenac ◽  
N. Nikolic ◽  
D.L. Sekulic ◽  
O.S. Aleksic ◽  
...  

The effects of Zn-doping on the dielectric behavior and electrical properties of bulk ?-Fe2O3 have been studied. X-ray diffraction analysis revealed the presence of two phases in all samples: hematite and spinel ZnFe2O4, with the amount of spinel phase increasing with increasing Zn content. Scanning electron microscopy analysis combined with energy dispersive X-ray spectroscopy showed that the Zn-bearing phase occurred in the form of individual spinel ZnFe2O4 grains in a hematite matrix. DC conductivity was measured in the temperature range 25-225oC (298-498 K). Impedance spectroscopy measurements in the same temperature range were carried out in the frequency range 100Hz to 10 MHz. Increase in the Zn content resulted in increased electrical conductivity and higher values of the dielectric constant. The resistance and capacitance of grains and grain boundaries were analyzed by modeling the experimental results using an equivalent circuit.


2013 ◽  
Vol 662 ◽  
pp. 163-166 ◽  
Author(s):  
Chu Bei Wang ◽  
Jian Wei Zhou ◽  
Liang Liang Chu ◽  
Jian Feng Liu

Abstract. The surface plasmon resonance photocatalysts of Ag-AgBr/RGO were synthesized by chemical precipitation and photochemical reduction method. The samples were characterized by X-ray diffraction and UV-Vis absorption spectroscopy. The photocatalytic activities of catalysts were studied using the photocatalytic degradation of helianthine as a probe reaction. The results showed that the degradation rate of 10 mg/L helianthine reached 95% after 60 min of visible light irradiation.


2014 ◽  
Vol 46 (3) ◽  
pp. 377-383
Author(s):  
R. Souag ◽  
N. Kamel ◽  
Y. Mouheb ◽  
M. Hammadi ◽  
Z. Kamel ◽  
...  

New nuclear glass-ceramics are extensively studied for the radioactive waste confinement, due to the double confinement conferred by the glass-ceramics. In this study, a glass-ceramic constituted by an aluminosilicate glass in the system: SiO2-Al2O3-CaO-MgOZrO2-TiO2, containing 2wt.% of Ca0.83Ce0.17ZrTi1.66Al0.34O7 zirconolite, has been synthesized by the discontinuous method. Cerium, an actinide surrogate is introduced both in the glass and ceramic phases. The synthesis is performed by a double melting at 1350?C, followed by a nucleation at 564?C, during 2 h, and a crystal growth at 1010?C during 3 h. Then effect of Ca/Mg ratio on the distribution of the crystalline network in the material was studied for Ca / Mg ratios ranging from 0.4 to 5.5. For the whole of the materials, Archimedes density is about 2.80 g/cm3. X-ray diffraction (XRD) analysis shows that the increase of Ca/Mg ratio leads to the increase of aluminosilicated crystalline phases with high Ca contents; the materials molar volumes remaining constant. The zirconolite phase is not affected by these additive aluminosilicated phases. The scanning electron microscopy analysis (SEM) coupled with energy dispersive X-ray (EDX) analysis confirmed these results; and shows the uniformity of distribution of the ceramics in the bulk of the materials.


2012 ◽  
Vol 620 ◽  
pp. 219-223 ◽  
Author(s):  
Mohd Fariz Ab Rahman ◽  
Julie Juliewatty Mohamed ◽  
Mohd Fadzil Ain ◽  
Sabar Derita Hutagalung

The properties of undoped and Mg-doped CaCu3Ti4O12 (CCTO) ceramics have been studied. The samples were calcined at 900°C for 12 hours, and sintered at 1030°C for 10 hours. X-ray diffraction analysis on calcined samples shown the formation of CCTO phase with trace of secondary phases meanwhile completed formation of CCTO single phase obtained for sintered pellets. The peak positions of Mg-doped CCTO were slightly left-shifted from the undoped CCTO, attributed to the lattice expansion. Scanning electron microscopy analysis showed that the grains size becomes larger with the increment of dopant amount. Enhanced dielectric constant was observed in the Ca1-xMgxCu3Ti4O12 ceramics with x = 0.05 for the frequency range from 1 MHz to 1 GHz. The dielectric loss seem to be at lowest value when Ca1-xMgxCu3Ti4O12 ceramics with x = 0.10 at the same frequency range. The results indicate that Mg ions have effectively changed the properties of CCTO.


2013 ◽  
Vol 807-809 ◽  
pp. 562-566
Author(s):  
Wei Dong Shi ◽  
Dan Yan ◽  
Wei Qiang Fan

Four kinds of Cu2O microcrystals with different morphologies are synthesized via low temperature hydrothermal synthetic method. The photocatalytic degradation of methylene blue (MB) of the above different Cu2O is preliminary explored based on this observation. 6-facet, 8-facet, 14-facet are prepared by PVP system and 26-facet is prepared by NaOH system. They are characterized by means of Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Diffuse Reflectance Spectra (DRS). Under 150 W xenon lamp irradiation, 0.5 gL1 catalyst and 0.1% (v/v) 30% H2O2 as co-catalyst are used to degrade 5% 100 mL MB solution. The reaction time is 80 min. 26-facet Cu2O polyhedral discolor about 89.48% of MB while 6-facet Cu2O microcrystal about discolor about 20.18% which is the lowest decolourization rate among all the samples. The photocatalytic performance of 8-facet Cu2O microcrystal is slight better than that of 14-facet. The decolourization rate of 8-facet and 14-facet are 56.00% and 41.08%, respectively. The main reason is that the planes of Cu2O microcrystal have a main influence on photocatalytic degradation of MB.


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