Spectroscopic Study of Rod-Like Mesoporous ZnO-SiO2 Composites

2007 ◽  
Vol 336-338 ◽  
pp. 2267-2270
Author(s):  
Chun Xia Zhao ◽  
Wen Chen ◽  
Qi Liu ◽  
Li Qiang Mai

Novel mesoporous ZnO-SiO2 (MZS) composites with rod-like morphology were synthesized from coprecipitation method, which was the first time to apply this method in the successful synthesis of ordered mesoporous composites to our knowledge. This direct-synthesis method was more simple, convenient and efficient, compared with the post-synthesis ones. Structural characterization and spectroscopic study were discussed.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Azam Marjani ◽  
Reza Khan Mohammadi

AbstractHg(II) has been identified to be one of the extremely toxic heavy metals because of its hazardous effects and this fact that it is even more hazardous to animals than other pollutants such as Ag, Au, Cd, Ni, Pb, Co, Cu, and Zn. Accordingly, for the first time, tetrasulfide-functionalized fibrous silica KCC-1 (TS-KCC-1) spheres were synthesized by a facile, conventional ultrasonic-assisted, sol–gel-hydrothermal preparation approach to adsorb Hg(II) from aqueous solution. Tetrasulfide groups (–S–S–S–S–) were chosen as binding sites due to the strong and effective interaction of mercury ions (Hg(II)) with sulfur atoms. Hg(II) uptake onto TS-KCC-1 in a batch system has been carried out. Isotherm and kinetic results showed a very agreed agreement with Langmuir and pseudo-first-order models, respectively, with a Langmuir maximum uptake capacity of 132.55 mg g–1 (volume of the solution = 20.0 mL; adsorbent dose = 5.0 mg; pH = 5.0; temperature: 198 K; contact time = 40 min; shaking speed = 180 rpm). TS-KCC-1was shown to be a promising functional nanoporous material for the uptake of Hg(II) cations from aqueous media. To the best of our knowledge, there has been no report on the uptake of toxic Hg(II) cations by tetrasulfide-functionalized KCC-1 prepared by a conventional ultrasonic-assisted sol–gel-hydrothermal synthesis method.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3854
Author(s):  
Hugo Martínez Sánchez ◽  
George Hadjipanayis ◽  
Germán Antonio Pérez Alcázar ◽  
Ligia Edith Zamora Alfonso ◽  
Juan Sebastián Trujillo Hernández

In this work, the mechanochemical synthesis method was used for the first time to produce powders of the nanocrystalline Nd1.1Fe10CoTi compound from Nd2O3, Fe2O3, Co and TiO2. High-energy-milled powders were heat treated at 1000 °C for 10 min to obtain the ThMn12-type structure. Volume fraction of the 1:12 phase was found to be as high as 95.7% with 4.3% of a bcc phase also present. The nitrogenation process of the sample was carried out at 350 °C during 3, 6, 9 and 12 h using a static pressure of 80 kPa of N2. The magnetic properties Mr, µ0Hc, and (BH)max were enhanced after nitrogenation, despite finding some residual nitrogen-free 1:12 phase. The magnetic values of a nitrogenated sample after 3 h were Mr = 75 Am2 kg–1, µ0Hc = 0.500 T and (BH)max = 58 kJ·m–3. Samples were aligned under an applied field of 2 T after washing and were measured in a direction parallel to the applied field. The best value of (BH)max~114 kJ·m–3 was obtained for 3 h and the highest µ0Hc = 0.518 T for 6 h nitrogenation. SEM characterization revealed that the particles have a mean particle size around 360 nm and a rounded shape.


2021 ◽  
Author(s):  
Lulin Wang ◽  
Guangyi Li ◽  
Cong Yu ◽  
Ai-Qin Wang ◽  
Xiaodong Wang ◽  
...  

For the first time, propane-2,2-diyldicyclohexane, a jet fuel range C15 dicycloalkane was directly produced by the aqueous-phase hydrodeoxygenation (APHDO) of polycarbonate (PC). Among the investigated catalyst systems, a mixture of...


2011 ◽  
Vol 115 (5) ◽  
pp. 1375-1379 ◽  
Author(s):  
Alexej Chernikov ◽  
Swantje Horst ◽  
Thomas Waitz ◽  
Michael Tiemann ◽  
Sangam Chatterjee

2014 ◽  
Vol 1048 ◽  
pp. 452-455
Author(s):  
Qiang Wang ◽  
Shi Dong Wang ◽  
Ming Chen Qi ◽  
Shu Liang Zang

Two new imidazole ionic liquid salts, 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-allyl-3-methy-imidazolium hydrogen sulfate ([EMIM]HSO4), were synthesized with direct synthesis and two-step synthesis method, using a viscosity meter, PH meter, conductivity meter, densitometer, infrared spectrometer determined its chemical structure and properties. The results show that two ionic liquids in the range is slightly different, the trend is roughly same. As the temperature increases, the viscosity decreases, PH gradually increased, the density decreases slightly, can be regarded as constant, the conductivity gradually increased. Ionic liquids of the two IR spectra analysis show its structure and synthetic route consistent with the structure of matter.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. El-Sheikh

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40°C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25°C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1–21 nm and the highest counts % of these particles were for particles of 6–10 and 1–3 nm, respectively.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Akshay Rajeev Geetha ◽  
Elizabeth George ◽  
Akshay Srinivasan ◽  
Jameel Shaik

Production of silver nanoparticles from the leaf extracts ofPimenta dioicais reported for the first time in this paper. Three different sets of leaves were utilized for the synthesis of nanoparticles—fresh, hot-air oven dried, and sun-dried. These nanoparticles were characterized using UV-Vis spectroscopy and AFM. The results were diverse in that different sizes were seen for different leaf conditions. Nanoparticles synthesized using sun-dried leaves (produced using a particular ratio (1 : 0.5) of the leaf extract sample and silver nitrate (1 mM), resp.) possessed the smallest sizes. We believe that further optimization of the current green-synthesis method would help in the production of monodispersed silver nanoparticles having great potential in treating several diseases.


2011 ◽  
Vol 312-315 ◽  
pp. 20-26
Author(s):  
Zahra Fakhroueian ◽  
Pouriya Esmaeilzadeh ◽  
N. Afroukhteh Langroudi ◽  
H. Varmazyar ◽  
M. Ahmadirad ◽  
...  

The synthesis of nanostructures are very various, and the most of scientists always fabricate them by the coprecipitation method at pH = 10.5-11. If we prepare these nanocatalysts for partial oxidation of methane (POM), processes to transforme methane gas into hydrogen or synthesis gas (H2 + CO) for obtaining exact green fuel H2 gas at different pH, what will be occurring?, and what is the influence of pH on nanoemulsion, nanofluids, nanostructures, and finally the application in syngas process? In this study we prepared many different nanoparticles containing % x (w/w) Co, Ni, Ru and La oxides over the various supports e.g. Ce-ZrO2, MgO-CeO2, AlCeO2, SiO2, SiAl2O3, SiMgO, SiO2Al-MCM-41 nano mixed oxides sized (1-2 nm) at various pH (7, 8, 9, 11) by new coprecipitation and combine with nanofluids method using different direct agent surfactant, stabilizer, binder, alcohol solvent, dispersant and variable chemical pH controllers. The prepared nanostructures were characterized by common techniques such as SEM, TEM, XRD, Raman, FTIR, BET and TPR analysis at various pH. Also many marvellous and new mixture of nanotubes-nanoclay and nanotubes-nanocomposites with high % H2 selectivity and methane conversion were fabricated by CuOx and NiOx sputtering test followed coprecipitation method at pH 9, for POM reactions used in petrochemical industry for the first time.


2020 ◽  
Vol 850 ◽  
pp. 144-150
Author(s):  
Agija Stanke ◽  
Valdis Kampars ◽  
Oana A. Lazar ◽  
Marius Enachescu

In this study Fe2O3/SBA-15 catalyst was synthesized via direct synthesis method under acidic conditions using triblock copolymer Pluronic P123 as template, tetraethyl orthosilicate as a silica source and Fe (NO3)3∙9H2O as iron source. Template was removed using extraction and calcination. The obtained catalyst was characterized using XRD analysis, WDXRF spectroscopy, N2 adsorption-desorption analysis and STEM–EDX measurements. Results of catalyst characterization showed that the synthesized Fe2O3/SBA-15 is mesoporous silica with 2D p6mm hexagonal mesostructure loaded with 15.6 wt.% Fe2O3. Average pore size was 6.95 nm, homogeneous immobilized Fe2O3 nanoparticles do not disrupt the porous hexagonal structure of the support.


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