ChemInform Abstract: Non-Aqueous Sol-Gel Routes to Metal Oxide Nanocrystals under Solvothermal Conditions: Review and Case Study on Doped Group IV Metal Oxides

ChemInform ◽  
2010 ◽  
Vol 41 (42) ◽  
Author(s):  
Andrea Pucci ◽  
Nicola Pinna
2010 ◽  
Vol 65 (8) ◽  
pp. 1015-1023 ◽  
Author(s):  
Andrea Pucci ◽  
Nicola Pinna

Over the last decade, the number of publications concerning the non-aqueous sol-gel synthesis of metal oxide nanostructures has rapidly increased, as this method affords an immense variety of sizes and shapes of the products. This review highlights the versatility of non-aqueous sol-gel routes, under solvothermal conditions, to metal oxide and hybrid materials. In particular, the easier control over the reaction kinetics, compared to aqueous methods, allows to better match the reactivity between metal oxide precursors. This permits to produce complex multimetal and doped oxides at low temperature, as it is discussed in detail for the case of doped group IV metal oxides


2011 ◽  
Vol 474-476 ◽  
pp. 195-199 ◽  
Author(s):  
Ai Hong Guo ◽  
Xue Jiao Tang ◽  
Su Juan Zhang

Water-based infrared ray shielding coating, that is, nanometer metal oxide is added to the water-based paint, which has anti-IR features without affecting the transparency of the paint. In this paper, the nanometer oxides are prepared by sol-gel method, added into polypropylene sour. In order to improve the infrared ray shielding of the thin film, two kinds of nanometer oxides are added into the polypropylene sour with different volume ratios, the shielding performance of the paint is studied. Experimental results show: in the 8000 ~ 4000cm-1 range, the transmittances of infrared ray is 30% to 75%; in 4000 ~ 400cm-1 range, transmittances decrease significantly; 3% ZnO, 3% Fe2O3, 3% Y2O3, 2% Al2O3 are the best mass ratio of every single nanometer oxide; the infrared shielding rate of Fe2O3 and Y2O3 mixture with the volume ratio of 1 to 4 is better than Fe2O3 and Y2O3 single.


2016 ◽  
Vol 4 (11) ◽  
pp. 4032-4043 ◽  
Author(s):  
Jianchao Ye ◽  
Yonghao An ◽  
Elizabeth Montalvo ◽  
Patrick G. Campbell ◽  
Marcus A. Worsley ◽  
...  

The conversion-reaction-based metal oxide/graphene aerogels show much higher capacitive synergy than that observed for intercalation-based TiO2/graphene aerogels.


2013 ◽  
Vol 1539 ◽  
Author(s):  
Edward G. Gillan

ABSTRACTA major challenge in utilizing living botanical materials, such as cellular leaf structures, as templates is that they are filled with water and conventional dehydration strategies often collapse or degrade the intricate botanical structure. This restricts the ability to introduce water reactive precursors into such structures. We have developed a room-temperature chemical method using acidified 2,2-dimethoxypropane to dehydrate water-rich botanical materials (e.g., fern leaves and water-rich jade succulents). This mild dehydration process leaves much of the porous cellular leaf structure intact even with ∼90% mass loss. These chemically dehydrated templates have been utilized in the growth of porous and ordered leaf replicate structures consisting of TiO2 and SiO2 via sol-gel precursor impregnation methods. These white metal oxide products exhibit external and internal structures that look very similar to their original templates, but are shrunken intact versions of the original. This paper details the chemical procedures that enable one to effectively use sensitive botanical templates in metal oxide growth. The physical and structural properties of several dried porous templates and macroporous anatase TiO2 and amorphous or crystoballite SiO2 products will be described. Recent efforts to use these botanical templates to produce other porous metal oxides (e.g., Co3O4, NiO, and CuO) using both halide and acetate precursor impregnation strategies are noted. Porous metal oxides with interconnected pore walls may have use in electrochemical energy storage systems, including in photocatalytic, photovoltaic or battery systems.


2010 ◽  
Vol 1256 ◽  
Author(s):  
Martin Jarvekulg ◽  
Raul Välbe ◽  
Kathriin Utt ◽  
Martin Timusk ◽  
Tanel Tätte

AbstractIn present paper we describe some unconventional adaptions of sol-gel method. Controlled sol-gel transformation processes of metal alkoxide based systems can lead to various novel shapes of metal alkoxide materials. Formation of different structures like tubular microstructures by gel sheet rolling, nano- and microfibres by direct drawing, as well as microtubes of metal oxides and gel dispersed liquid crystal materials are described. Different aspects of sol-gel processes leading to the formation of all of these structures are thereby discussed.


2018 ◽  
Vol 6 (41) ◽  
pp. 20444-20453 ◽  
Author(s):  
Maxwell A. Astle ◽  
Graham A. Rance ◽  
Michael W. Fay ◽  
Stuart Notman ◽  
Mark R. Sambrook ◽  
...  

The enhanced catalytic properties of hydroxylated group IV metal oxide nanostructures confined within hollow graphitised carbon nanofibers has been demonstrated.


1999 ◽  
Vol 14 (1) ◽  
pp. 5-7 ◽  
Author(s):  
Takuya Hori ◽  
Noriyuki Kuramoto ◽  
Hideyuki Tagaya ◽  
Masa Karasu ◽  
Jun-ichi Kadokawa ◽  
...  

Conducting thin films were prepared by entrapping water-suspended polyaniline into a silica matrix by a sol-gel route. Without metal oxide, the conductivity of the film decreased after heat treatment. However, in the presence of metal oxides such as TiO2 and Al2O3, the conductivity increased after heat treatment at 85 °C and reached 17 Scm−1 The conductivity of the film depended on the kinds and amounts of metal oxides and the temperature of heat treatment.


2002 ◽  
Vol 752 ◽  
Author(s):  
Masashi Asaeda ◽  
Masakoto Kanezashi ◽  
Tomohisa Yoshioka ◽  
Toshinori Tsuru

ABSTRACTIn order to improve the stability of silica membranes against water (vapor) some metal oxides were added to silica to obtain composite silica-metal oxide membranes by the sol-gel techniques. A Ni-doped silica membrane (Ni/Si=1/2) fired at 500°C showed a relatively large permeance of 1.5×10−5 [m3(STP)/(m2skPa)] with selectivity of 350 (H2/CH4), 4200 (H2/SF6) at 200°C and 100 (CO2/CH4) at 35 °C. After leaving the membrane in humid air (RH: 60%, 40°C) for 70 days, the permeance of H2 decreased by about 50% but the selectivity was improved to 930 for H2/CH4. And little change was observed in the activation energy for H2 permeation, while under the same conditions a silica membrane showed a quite large change in the activation energy from 3.1kJ/mol to 14kJ/mol. There is a possibility that metal oxides added to silica help prevent the densification of silica networks through which hydrogen and helium molecules can permeate.


2018 ◽  
Vol 42 (1) ◽  
pp. 402-410 ◽  
Author(s):  
Jhumur Seth ◽  
Prashant Dubey ◽  
Vijay R. Chaudhari ◽  
Bhagavatula L. V. Prasad

A convenient way of anchoring transition metal nanoparticles onto metal oxides by means of a toluene mediated sol–gel method is described.


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