scholarly journals POTENTIAL OF ILMENITE AS A SOLAR ABSORBER

2020 ◽  
Vol 19 (2) ◽  
pp. 59
Author(s):  
G. C. P. Sousa ◽  
K. C. Gomes ◽  
W. F. A. Júnior ◽  
R. N. C. Duarte

Titanium is considered the fourth most widely used material in industry worldwide. Titanium minerals are currently being applied in various branches of industry, mainly in the field of pigmentation. Ilmenite (FeTiO3) is an iron and titanium oxide of more common and abundant occurrence, with theoretical composition of Fe (36.8%), Ti (31.6%) and O (31.6%). Having regard to the potential of titanium minerals and the abundance of ilmenite, together with the importance of validating direct applications of this ore, since the processing of titanium is still complex and expensive, it is necessary to study this mineral and the knowledge of its main characteristics. This work brings thermal, chemical and mineralogical characterizations of ilmenite, in order to know the potential of application of this ore as a solar absorbing material. The characterization techniques used were: X-ray diffraction (XRD) and Rietveld refinement for phase quantification, X-ray fluorescence (XRF), optical spectroscopy in the middle infrared region with Fourier Transformation by Transmittance (FTIR) and thermogravimetric thermal analysis (TGA). The analyzed sample obtained X-ray diffractogram, ilmenite (80.6%) and rutile (19.4%) as significant phases, corroborating the FRX results that indicated greater presence of Fe and titanium oxide in the ilmenite chemical composition under study. The TGA, DTA and DSC analyses indicated good thermal stability of the material in medium and high temperatures. The integration of the obtained data shows that the application of this ore as a precursor material of absorber films for selective purposes is considerable.

2000 ◽  
Vol 55 (1-2) ◽  
pp. 291-297 ◽  
Author(s):  
T. J. Bastow

Some recent progress in solid state 47,49Ti NMR is described and reviewed. The metallic-state work described covers metals such as hep titanium, TiB2 , a number of intermetallics such as TiAl2 and TiAl3· The inorganic work covers the various titanium oxide based materials including the TiO2 polymorphs, anatase, rutile and brookite. The gel work covers the evolution of crystalline titania from gels formed by hydrolysis of titanium isopropoxide. Some complementary data from 17O and 13C NMR and powder X-ray diffraction is also included.


2015 ◽  
Vol 245 ◽  
pp. 200-203 ◽  
Author(s):  
Maxim Alexandrovich Pugachevskii ◽  
Viktor Igorevich Panfilov

The conditions of formation of the ZrO2 and HfO2 high-temperature (tetragonal and cubic) phases in the ablated nanoparticles were investigated. X-ray diffraction and transmission electron microscopy data demonstrate that laser intensities above 109 W/m2 ensure the formation of the ZrO2 high-temperature phases, while intensities above 5·109 W/m2 do the formation of the HfO2 high-temperature phases. Quantitative content of the high-temperature phases in layers of the ablated nanoparticles increases with raising the intensity. The obtained nanoparticles exhibit good thermal stability.


2019 ◽  
Vol 75 (5) ◽  
pp. 508-513 ◽  
Author(s):  
Bin Xu ◽  
Fuming Luo ◽  
Guodong Tang ◽  
Jinfang Zhang

The title coordination polymer, poly[bis[μ3-4-(3,2′:6′,3′′-terpyridin-4′-yl)benzoato]cadmium(II)], [Cd(C22H14N3O2)2] n or [Cd(3-cptpy)2] n , (I), has been synthesized solvothermally and characterized by IR spectroscopy, thermogravimetric analysis, and single-crystal and powder X-ray diffraction. The structure is composed of 3-cptpy− ligands bridging Cd atoms, with each Cd atom coordinated by six ligands and each ligand coordinating to three Cd atoms. Each Cd atom is in a slightly distorted trans-N2O4 octahedral environment, forming a two-dimensional layer structure with a (3,6)-connected topology. Layers are linked to each other by π–π stacking, resulting in a three-dimensional supramolecular framework. The strong luminescence and good thermal stability of (I) indicate that it can potentially be used as a luminescence sensor. The compound also shows a highly selective and sensitive response to 2,4,6-trinitrophenol through the luminescence quenching effect.


2014 ◽  
Vol 67 (10) ◽  
pp. 1387 ◽  
Author(s):  
Shi-Qiang Bai ◽  
Lu Jiang ◽  
Sheng-Li Huang ◽  
Ming Lin ◽  
Shuang-Yuan Zhang ◽  
...  

Composite Pd/Fe3O4 (1) was designed and synthesised by immobilization of tridentate pincer ligands with triethoxysilane groups on Fe3O4 nanoparticles, PdII complexation, and in-situ reduction process. The composite was characterised by transmission electron microscopy, scanning electron microscopy energy-dispersive X-ray spectroscopy, powder X-ray diffraction, vibrating sample magnetometer, Fourier transform infrared spectroscopy, thermogravimetric analysis, and Brunauer–Emmett–Teller analysis. The composite featured Pd nanoparticles of ~2–4 nm, exhibited good thermal stability and hydrophilic property as well as excellent catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol in water.


2015 ◽  
Vol 08 (05) ◽  
pp. 1550063 ◽  
Author(s):  
Sara Hoomi ◽  
Ramin Yousefi ◽  
Farid Jamali-Sheini ◽  
Abdolhossein Sáaedi ◽  
Mohsen Cheraghizade ◽  
...  

PbSe nanostructures were synthesized by selenization of lead sheets in a chemical vapor deposition (CVD) set-up under a selenium ambiance. The lead sheets were placed in the different temperature zones, between 300°C and 450°C. Field emission scanning electron microscope (FESEM) images showed that, PbSe nanostructures grown on the lead sheets with different morphologies. PbSe nanostructures with flakes shape were grown on the lead sheets that were placed in the lower temperature, while PbSe nanocubes and nanorods, which were grown on the nanocubes, were grown on the lead sheets in the higher temperature. The phase and composition of the product were identified by X-ray diffraction (XRD) pattern and X-ray photoelectron spectra (XPS). The XRD and XPS results showed that, the PbSe phase was started to form after 350°C and completed at 450°C. However, the XPS results showed that the Se concentration was different in the samples. In addition, Raman measurements confirmed the XRD and XPS results and indicated three Raman active modes, which belonged to PbSe phase for the nanostructures. The optical properties of the products were characterized by UV–Vis. The optical characterization results showed a band gap for the PbSe nanostructures in the infrared region.


2005 ◽  
Vol 900 ◽  
Author(s):  
A. Deptuła ◽  
Kenneth C Goretta ◽  
Tadeusz Olczak ◽  
Wieslawa Lada ◽  
Andrzej G. Chmielewski ◽  
...  

ABSTRACTTitanium oxide and titanates based on Ba, Sr and Ca were prepared from commercial solutions of TiCl4 and HNO3. The main preparation steps for the sols consisted of elimination of chloride anions by distillation with nitric acid and addition of metal hydroxides for the titanates. Resulting sols were gelled and used to (1) prepare irregularly shaped powders by evaporation; (2) produce by a dipping technique thin films on glass, Ag, or Ti substrates; and (3) produce spherical powders (diameters <100 μm) by solvent extraction. Results of thermal and X-ray-diffraction analyses indicated that the temperatures required to form the various compounds were lower than those necessary to form the compounds by conventional solid-state reactions and comparable to those required with use of organometallic based sol-gel methods. Temperatures of formation could be further reduced by addition of ascorbic acid to the sols.


1992 ◽  
Vol 70 (7) ◽  
pp. 1927-1931 ◽  
Author(s):  
N. K. Labhsetwar ◽  
O. P. Shrivastava

Montmorillonite is a natural layered clay mineral having myriad applications due mainly to its remarkable ion exchange, intercalation, and swelling properties. It can act as a good host for several compounds. Two intercalated coordination compounds of Cu(II) and Ni(II) with 2,2′-bipyridyl have been prepared in the interlayer spaces of montmorillonite structure. They are characterized on the basis of elemental analysis, infrared spectroscopy, magnetic studies, and X-ray diffraction. Both compounds show similarity in their structure and properties with the respective normal complexes of similar composition. These compounds show good thermal stability. The present intercalated compounds might be useful for their nitrogen-immobilizing properties and high-temperature applications.


2015 ◽  
Vol 1118 ◽  
pp. 20-27
Author(s):  
Jing Yang ◽  
Bao Song Li ◽  
Xiang Huo ◽  
Hao Xu ◽  
Hai Yun Hou

Pd/SiO2 organic-inorganic hybrid materials were prepared by adding PdCl2 into methyl-modified silica sol. The Pd/SiO2 hybrid materials were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of calcination temperature and Pd-doping on the phase transition of Pd element and the thermal stability of CH3 group in the Pd/SiO2 organic-inorganic hybrid materials were investigated. The results showed that the reduced metallic Pd0 exhibits good thermal stability under H2 atmosphere in the calcination process. Pd element in noncalcined Pd/SiO2 materials exists in PdCl2 form, calcination at 200 °C in a H2 atmosphere produces some metallic Pd0 and calcinations at 350 °C results in the complete transformation of Pd2+ to metallic Pd0. With the increase of calcination temperature, the Pd0 particle sizes increase and the hydrophobic Si−CH3 bands decrease in intensity. As the calcination temperature is greater than or equal to 350 °C, the loading of metallic Pd0 nearly has no influence on the chemical structure but, with the increase of Pd content, the formed Pd0 particle size increases. To keep the hydrophobicity of Pd/SiO2 membrane materials, the optimal calcination temperature is about 350 °C under H2 atmosphere.


2016 ◽  
Vol 70 (3) ◽  
Author(s):  
Ming-Feng Song ◽  
Zhong-Fang Li ◽  
Guo-Hong Liu ◽  
Su-Wen Wang ◽  
Xiao-Yan Yin ◽  
...  

AbstractLanthanum sulfophenyl phosphate (LaSPP) was synthesized by m-sulfophenyl phosphonic acid and lanthanum nitrate. UV-Vis spectrophotometry and Fourier-transform infrared spectroscopy indicate that the desired product was obtained and its elementary composition and typical layered structure were determined by energy dispersive X-ray spectroscopy and scanning electron microscopy. Transmission electron microscopy (TEM) proved its typical layered structure and X-ray diffraction spectroscopy indicated its good crystallinity and the interlayer distance of about 15.67 Å , which matches the value obtained by TEM (2.0 nm). Thermogravimetry and differential thermal analysis revealed good thermal stability of LaSPP. Proton conductivity of LaSPP was measured at different temperatures and relative humidities (RH), reaching values of 0.123 S cm


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