Iron oxide-silica nanocomposites yielded by chemical route and sol–gel method

2016 ◽  
Vol 79 (3) ◽  
pp. 457-465 ◽  
Author(s):  
E. Puscasu ◽  
L. Sacarescu ◽  
N. Lupu ◽  
M. Grigoras ◽  
G. Oanca ◽  
...  
2019 ◽  
Vol 9 (3) ◽  
pp. 362-370 ◽  
Author(s):  
D. Vaya ◽  
Meena ◽  
B.K. Das

Background: The properties of the material are altered when material size shifted towards nano-regime. This feature could be used for wastewater treatment process using model pollutant such as dyes. Recently, nanoparticles are synthesized by a green chemical route using different capping agents. This is the reason we adopt starch as green capping agent along with sol-gel method. Objective: To synthesize cobalt oxide nanoparticles by green chemical route and utilized it in degradation of dyes. Methods: Synthesis of cobalt oxide nanoparticles by sol-gel method using starch as a capping agent. The characteristics of surface modifications were investigated by UV-VIS, TEM, SEM, XRD and FTIR techniques. Results: Cobalt oxide nanoparticles synthesized and inhibited photocatalytic activity. Conclusion: Deactivation of photocatalytic activity due to complex nature of starch. This property can be used elsewhere as in light shielding applications to coat and protect surfaces in order to keep them cool and safe from damage as in the painting of vehicles, roofs, buildings, water tanks, etc.


2007 ◽  
Vol 46 (1) ◽  
pp. 43-54 ◽  
Author(s):  
J. A. Gómez Tejedor ◽  
J. C. Rodríguez Hernández ◽  
J. L. Gómez Ribelles ◽  
M. Monleón Pradas

2018 ◽  
Vol 09 (04) ◽  
Author(s):  
Rasheed RT ◽  
Al-Algawi SD ◽  
Kareem HH ◽  
Mansoor HS
Keyword(s):  
Sol Gel ◽  

2002 ◽  
Vol 17 (3) ◽  
pp. 590-596 ◽  
Author(s):  
G. Ennas ◽  
M. F. Casula ◽  
G. Piccaluga ◽  
S. Solinas ◽  
M. P. Morales ◽  
...  

γ–Fe2O3/SiO2 and Fe/SiO2 nanocomposites, with a Fe/Si molar ratio of 0.25, were prepared by the sol-gel method starting from ethanolic solutions of tetraethoxysilane and iron (III) nitrate. After gelation the xerogels were oxidated or reduced. Samples were investigated by transmission electron microscopy, x-ray diffraction, differential scanning calorimetry, and thermogravimetry. Magnetic properties of the samples were investigated at room temperature (RT) and at 77 K. Nanometric particles supported in the silica matrix were obtained in all cases. Bigger particles (10 nm) were obtained in the case of Fe/SiO2 nanocomposites with respect to the γ–Fe2O3/SiO2 samples (5–8 nm). A slight effect of sol dilution on particle size was observed only in the case of γ–Fe2O3/SiO2 nanocomposites. A superparamagnetic behavior was shown at RT only by γ–Fe2O3/SiO2 nanocomposites. Iron-based composites exhibited coercivity values higher than 700 Oe at RT.


2010 ◽  
Vol 58 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Marcela Stoia ◽  
Costica Caizer ◽  
Mircea Ştefănescu ◽  
Paul Barvinschi ◽  
Lucian Barbu-Tudoran

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Marcela F. Silva ◽  
Luiz A. S. de Oliveira ◽  
Mariani A. Ciciliati ◽  
Michele K. Lima ◽  
Flávio F. Ivashita ◽  
...  

Fe2O3 nanoparticles (as maghemite and hematite mixtures) were prepared using adapted sol-gel method from a polyvinylpyrrolidone (PVP) aqueous solution in various Fe3+ : PVP monomer ratios. Analysis of X-ray diffraction was obtained to evaluate the crystalline state, average crystallite size, and composition of iron oxide phases. The morphology and average nanoparticles size were evaluated by electronic transmission microscopy. Magnetic properties of iron oxide were analyzed at low and room temperatures. Optical characteristics were evaluated by UV-Vis photoacoustic spectroscopy and the Mössbauer spectrum was obtained in order to evaluate subtle changes in the nuclear environment of the iron atoms.


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