scholarly journals Efficiency of TiO2 catalyst supported by modified waste fly ash during photodegradation of RR45 dye

2019 ◽  
Vol 26 (1) ◽  
pp. 292-300 ◽  
Author(s):  
Vanja Gilja ◽  
Zvonimir Katančić ◽  
Ljerka Kratofil Krehula ◽  
Vilko Mandić ◽  
Zlata Hrnjak-Murgić
Keyword(s):  
Fly Ash ◽  
Gas Adsorption ◽  
Sol Gel ◽  
Efficiency Evaluation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Adsorption Desorption

AbstractThe waste fly ash (FA) material was subjected to chemical treatment with HCl at elevated temperature for a different time to modify its porosity. Modified FA particles with highest surface area and pore volume were further used as a support for TiO2 catalyst during FA/TiO2 nanocomposite preparation. The nanocomposite photocatalysts were obtained by in situ sol–gel synthesis of titanium dioxide in the presence of FA particles. To perform accurate characterization of modified FA and FA/TiO2 nanocomposite photocatalysts, gas adsorption-desorption analysis, X-ray diffraction, scanning electron microscopy, UV/Vis and Infrared spectroscopy were used. Efficiency evaluation of the synthesized FA/TiO2 nanocomposites was performed by following the removal of Reactive Red 45 (RR45) azo dye during photocatalytic treatment under the UV-A irradiation. Photocatalysis has been carried out up to five cycles with the same catalysts to investigate their stability and the possible reuse. The FA/TiO2 photocatalyst showed very good photocatalytic activity and stability even after the fifth cycles. The obtained results show that successfully modified waste fly ash can be used as very good TiO2 support.

Sol-Gel Synthesis and Characterization of Nanocrystalline Bi4Ti3O12 Powders

2014 ◽  
Vol 997 ◽  
pp. 359-362 ◽  
Author(s):  
Chun Hong Ma ◽  
Xue Lin ◽  
Liang Wang ◽  
Yong Sheng Yan
Keyword(s):  
Phase Inversion ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Synthesis ◽  
Source Materials

Nanocrystalline bismuth titanate (Bi4Ti3O12; BTO) powders were successfully prepared by the sol-gel method, using bismuth nitrate (Bi(NO3)3·5H2O) and tetrabutyl titanate (Ti(OC4H9)4) as source materials, acetic anhydride and ethanediol as solvents. The thermal decomposition and phase inversion process of the gel precursors were studied by using differential thermal analysis (DTA). The crystal structures and microstructures of BTO powders were investigated by using x-ray diffraction (XRD), and transmission electron microscope (TEM). The crystallization of amorphous bismuth titanate has been discussed. The effect of sintering temperature on the structure and morphology of BTO was investigated. At 644 oC and above, BTO powder undergoes a phase transformation from tetragonal to orthorhombic. At 900 oC, the purified orthorhombic BTO nanocrystals were obtained.

Synthesis and Characterization of Nanocrystalline CeO2

2006 ◽  
Vol 306-308 ◽  
pp. 1103-1108
Author(s):  
Abdul Hadi ◽  
Iskandar Idris Yaacob
Keyword(s):  
Fine Particles ◽  
Gas Adsorption ◽  
Mesoporous Structure ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered ◽  
Adsorption Desorption

Nanocrystalline CeO2 has been synthesized at room temperature using water-in-oil (w/o) microemulsion technique. The structure and properties of the nanocrystalline CeO2 were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and gas adsorption desorption measurement. XRD results showed the synthesized CeO2 has a face centered cubic structure with crystallite size of about 5.2 nm. TEM observation also indicated the presence of nanometer sized particles of CeO2. Coarser particles were also observed due to agglomeration. Gas adsorption desorption isotherms showed the behavior of fine particles with mesoporous structure.

Sol–Gel Synthesis and in Situ X-ray Diffraction Study of Li3Nd3W2O12 as a Lithium Container

2018 ◽  
Vol 10 (15) ◽  
pp. 12716-12721 ◽  
Author(s):  
Minghe Luo ◽  
Haoxiang Yu ◽  
Xing Cheng ◽  
Wuquan Ye ◽  
Haojie Zhu ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Synthesis

scholarly journals An Ecofriendly Synthesis of 2-oxazolidinone From 2-aminoethanol and Urea Under Solvent-free Condition Using CeO2 Nanoparticles

2021 ◽  
Author(s):  
ALI NEMATI KHARAT ◽  
Mehrnaz Aliahmadi
Keyword(s):  
Gas Adsorption ◽  
Sol Gel ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Solvent Free Condition ◽  
Solvent Free Conditions ◽  
Adsorption Desorption ◽  
Desorption Method

Abstract Cerium dioxide nanoparticles were prepared by the sol-gel method using cellulose as a template and used in the synthesis of 2-oxazolidinone from urea and 2-aminoethanol under solvent-free conditions. All the reaction parameters were optimized to obtain the best selectivity and conversion. The selectivity of 100 % to 2-oxazolidinone with a pretty complete conversion of about 98.4 % was achieved. The prepared catalyst was characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and volumetric isothermal nitrogen gas adsorption-desorption method (BET).

Anomaly in thermal characterization of CaxMg1-xNb2O6 (x =0,0.4,0.6,1) towards LTCC applications

2012 ◽  
Vol 36 (1) ◽  
pp. 13-19
Author(s):  
Jyotirmayee Satapathy ◽  
M.V.Ramana Reddy
Keyword(s):  
Thermal Instability ◽  
Dielectric Material ◽  
Raw Materials ◽  
Sol Gel ◽  
Thermal Characterization ◽  
Extensive Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Synthesis

Abstract Low temperature co-fired ceramics (LTCC), being the most advantageous technology related to the multilayer substrates for various applications, demands an extensive study of raw materials. In the present work, a series of CaxMg1−xNb2O6 (x =0, 0.4, 0.6, 1.0) were prepared using sol-gel synthesis route and sintered at a temperature of 900°C to study its applicability for LTCC technology. The phase formation has been confirmed using X-ray diffraction. Thermal properties like thermal conductivity and thermal expansion, which are very important aspects as the former defines the heat flow to avoid thermal instability in the layers and the latter provides the dimensional congruency of the dielectric material and the conductors, are studied here over high temperature range up to the firing temperature. Although the values are quite satisfactory from the application point view, the results have showed an anomaly over temperature. The anomalous thermal behavior was further analyzed using TG-DTA.

scholarly journals Sol-gel synthesis and study of neodymium substitution effects in Co-Al-Nd-O system with possible applications as novel inorganic pigments

2012 ◽  
Vol 10 (5) ◽  
pp. 1574-1583 ◽  
Author(s):  
Dalia Jonynaite ◽  
Darius Jasaitis ◽  
Rimantas Raudonis ◽  
Algirdas Selskis ◽  
Remigijus Juskenas ◽  
...  
Keyword(s):  
Sol Gel ◽  
Substitution Effects ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sol Gel Process ◽  
New Compounds ◽  
Sol Gel Synthesis

AbstractIn the present work, the formation of cobalt aluminium spinel (CoAl2O4) as well as novel cobalt neodymium-aluminates with nominal compositions of CoAl1.75Nd0.25O4, CoAl1.5Nd0.5O4 and CoAlNdO4 by an aqueous sol-gel process and the sinterability of the products are investigated. The metal ions, generated by dissolving starting materials of metals in the diluted acetic acid were complexed by 1,2-ethanediol to obtain the precursors for the mixed metal ceramics. The phase purity of the synthesized compounds was characterized by powder X-ray diffraction analysis and infrared spectroscopy. The microstructural evolution and morphological features of the products were studied by scanning electron microscopy and atomic force microscopy, which together with the optical characterization of these new compounds showed that the sol-gel-derived materials could be successfully used as effective cobalt-based ceramic pigments.

Sol-gel Synthesis, Magnetic and Structural Characterization of BaFe11.6–2xMxTixO19 (M=Co, Zn, Sn) Compounds.

2002 ◽  
Vol 755 ◽  
Author(s):  
G. Mendoza-Suárez ◽  
A.F. Fuentes ◽  
J.I. Escalante-García ◽  
O.E. Ayala-Valenzuela
Keyword(s):  
Magnetocrystalline Anisotropy ◽  
Sol Gel ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Barium Ferrites ◽  
Crystallite Sizes ◽  
Sol Gel Synthesis

ABSTRACTSubstituted barium ferrites powders with Ti4+-M2+ (M = Co, Zn, Sn) cationic mixtures were prepared by a sol-gel route. The materials were heat-treated in the range 925–1000 °C and characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The results showed that the effect of the substitution, x was to lower the coercivity (Hc), owing to the decrease of the magnetocrystalline anisotropy of the magnetoplumbite structure of the BaM. In this regard Sn-Ti substitutions tended to decrease Hc more rapidly than Zn-Ti and Ti-Co substitutions, in that order. Regarding the saturation magnetization (Ms), Zn-Ti mixtures showed slightly better Ms than Ti-Co substitutions; however, the Sn-Ti showed a more marked decrease as x increased. As revealed by SEM, the effect of the heat-treatment temperature was to increase the volume of multi-domain particles, following a Hc decrease due to grain coarsening. Contrarily, as a result of the improved crystallinity of the samples, as observed from the XRD peaks, Ms enhancement was recorded. Crystallite sizes decreased below 100 nm as x increased, although it was also dependent on the cationic mixture. In this respect Sn-Ti substitutions needed higher treatment temperatures to yield materials with adequate crystallinity and phase constitution.

In Situ Synchrotron X-ray Diffraction Study of the Sol–Gel Synthesis of Fe3N and Fe3C

2015 ◽  
Vol 27 (14) ◽  
pp. 5094-5099 ◽  
Author(s):  
Zoe Schnepp ◽  
Ashleigh E. Danks ◽  
Martin J. Hollamby ◽  
Brian R. Pauw ◽  
Claire A. Murray ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Synthesis

In-Situ Sol–Gel Synthesis of Nanophosphors M2Y8(SiO4)6O2:Eu3+(M = Ca, Sr) Derived from Novel Crosslinking Reagents as Silicon Sources

2008 ◽  
Vol 8 (3) ◽  
pp. 1261-1265 ◽  
Author(s):  
Lei Zhou ◽  
Bing Yan
Keyword(s):  
High Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Strong Emission ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Silicon Sources

M2Y8(SiO4)6O2:Eu3+(M = Ca, Sr) nanophosphors were synthesized using sol–gel technology by adopting eight different kinds of silicon sources of novel crosslinging reagents. X-ray diffraction and scanning electronic microscopy show that these materials have sizes of 20–80 nm with different configurations due to the diversity of the silicate sources. Some nanophosphors present the regular microstructure despite high temperature thermolysis. In addition, all these nanophosphors exhibit strong emission at 618 nm.

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