Surfactant-aided sol–gel synthesis of mesoporous-assembled TiO2–NiO mixed oxide nanocrystals and their photocatalytic azo dye degradation activity

2012 ◽  
Vol 192 ◽  
pp. 292-300 ◽  
Author(s):  
Thammanoon Sreethawong ◽  
Supachai Ngamsinlapasathian ◽  
Susumu Yoshikawa
Keyword(s):  
Mixed Oxide ◽  
Azo Dye ◽  
Dye Degradation ◽  
Sol Gel ◽  
Degradation Activity ◽  
Sol Gel Synthesis

scholarly journals Prospects for the use of mixed micellar structures as a template in synthesis of MCM-41-type silicas

2021 ◽  
pp. 79-89
Author(s):  
N.V. Roik ◽  
◽  
L.O. Belyakova ◽  
М.О. Dziazko
Keyword(s):  
Azo Dye ◽  
Cetyltrimethylammonium Bromide ◽  
Mixed Micelles ◽  
Hydrophobic Interactions ◽  
Sol Gel ◽  
Standard Free Energy ◽  
Reaction Medium ◽  
Total Pore Volume ◽  
Methyl Red ◽  
Sol Gel Synthesis

Formation of mixed micelles assisted by cetyltrimethylammonium bromide and methyl red was studied by means of conductometric and spectrophotometric methods. It follows from the analysis of conductometric dependences that the addition of azo dye leads to a decrease in critical micelle concentration of a long-chain quaternary ammonium salt. The respective thermodynamic parameters were calculated. The process of mixed micelles formation was stated to be spontaneous and the solubilization of azo dye by micelles of cetyltrimethylammonium bromide is profitable in terms of energy and accompanied by an increase in degrees of freedom of the system. Based on the data of spectrophotometric study of methyl red solutions in the presence of cetyltrimethylammonium bromide, the values of stability constant, partition coefficient and change in the standard free energy of methyl red distribution between aqueous and micellar medium were calculated. It was found that electrostatic and hydrophobic interactions arising between azo dye and cetyltrimethylammonium bromide molecules cause the orientation of methyl red from the shell towards the center of the micelles. It was shown that mixed micelles can be used as a template in sol-gel synthesis of mesoporous aminosilica of MSM-41 type. The results of low-temperature nitrogen adsorption-desorption and X-ray analysis revealed that the introduction of methyl red as a part of mixed micelles into the reaction medium of sol-gel synthesis causes substantial increase in specific surface area and total pore volume, noticeable reduction of pore diameter, thereby contributing to the formation of silica material with a pronounced long-range ordered mesoporous structure.

Sol–gel synthesis and structural characterization of niobium-silicon mixed-oxide nanocomposites

2007 ◽  
Vol 43 (2) ◽  
pp. 193-204 ◽  
Author(s):  
Antonio Aronne ◽  
Elisa Marenna ◽  
Valeria Califano ◽  
Esther Fanelli ◽  
Pasquale Pernice ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Mixed Oxide ◽  
Sol Gel ◽  
Sol Gel Synthesis

scholarly journals A versatile sol–gel synthesis route to metal–silicon mixed oxide nanocomposites that contain metal oxides as the major phase

2004 ◽  
Vol 350 ◽  
pp. 173-181 ◽  
Author(s):  
Brady J. Clapsaddle ◽  
David W. Sprehn ◽  
Alexander E. Gash ◽  
Joe H. Satcher Jr. ◽  
Randall L. Simpson
Keyword(s):  
Metal Oxides ◽  
Mixed Oxide ◽  
Sol Gel ◽  
Major Phase ◽  
Synthesis Route ◽  
Sol Gel Synthesis

scholarly journals Silica hybrid biomaterials containing gelatin synthesized by sol-gel method

2010 ◽  
Vol 8 (4) ◽  
pp. 870-876 ◽  
Author(s):  
Georgi Chernev ◽  
Borislava Borisova ◽  
Lyudmila Kabaivanova ◽  
Isabel Salvado
Keyword(s):  
Sol Gel ◽  
Bacterial Cells ◽  
Bet Analysis ◽  
Structure Surface ◽  
Potential Applications ◽  
Ft Ir ◽  
Degradation Activity ◽  
Sol Gel Synthesis ◽  
Hybrid Biomaterials ◽  
Silica Hybrid

AbstractThis work reports the sol-gel synthesis of silica hybrids. We determined the effect of the type and quantity of silica precursors and organic compounds on the resulting structure, surface area, nanostructure design and size, and potential applications. The structure of the synthesized hybrids was analyzed using FT-IR, XRD, BET-Analysis, SEM, and AFM. We demonstrate the immovilization of whole living thermophilic bacterial cells with cyanocompound degradation activity in the synthesized silica hybrid biomaterials by entrapment, chemical binding, and adsorption.

Sol-gel Synthesis of Porous Crystalline TiO2–P2O5 Oxide with Thermal Stability

2003 ◽  
Vol 18 (12) ◽  
pp. 2743-2746 ◽  
Author(s):  
Donglin Li ◽  
Haoshen Zhou ◽  
Mitsuhiro Hibino ◽  
Itaru Honma
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Solid State ◽  
Block Copolymer ◽  
Specific Surface ◽  
Mixed Oxide ◽  
Glass Phase ◽  
Sol Gel ◽  
Anatase Structure ◽  
Sol Gel Synthesis

Porous TiO2–P2O5 oxide was synthesized by the sol-gel method in the presence of tri-block copolymer (EO)20(PO)70(EO)20 (Pluronic123) in queous solution. The TiO2 nanocrystals with anatase structure precipitated in the as-synthesized TiO2–P2O5 materials at 80°C, considerably lower than that for traditional heat treatment in the solid state, which maintained a stable size of 3.6–4 nm upon calcinations below 500°C. It is believed that P2O5 glass phase prevents the coarsening of TiO2 nanocrystals below 500°C. The mixed oxide exhibited a specific surface area of 170–200 m2/g after calcining in the temperature range of 300–500°C.

Advanced Photocatalysis with Anatase Nano-coated Multi-walled Carbon Nanotubes

2005 ◽  
Vol 876 ◽  
Author(s):  
Georgios Pyrgiotakis ◽  
Sung-Hwan Lee ◽  
Wolfgang Sigmund
Keyword(s):  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Azo Dye ◽  
Dye Degradation ◽  
Sol Gel ◽  
Novel Approach ◽  
Nano Coating ◽  
Multi Walled Carbon Nanotubes ◽  
Degussa P25 ◽  
Walled Carbon Nanotubes

AbstractA novel approach is presented to synergistically enhance photocatalytic activity in a nanocomposite using the high aspect ratio of carbon nanotube (CNT) and their unique electrical properties. Composite nanoparticles were synthesized with sol-gel nano-coating on multi-walled carbon nanotubes (MWNTs). The nanostructure was characterized using SEM, TEM, XRD, Raman, FTIR and UV-VIS spectroscopies. Photocatalytic efficiencies of commercial photocatalysts (Degussa P25) and TiO2 nano-coated MWNTs were evaluated by Azo dye degradation tests. Superior photocatalytic activity was observed for the nanocomposite with UV-A and with visible light only irradiation.

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