Time filter

Source Type

Yan R.,Nankai University | Zhang M.,Nankai University | Zhang W.,Nankai University | Liu S.,Institute of New Catalytic Materials Science
Journal of Sol-Gel Science and Technology

Temperature dependent synthesis of micro- and meso-porous silica employing the thermo-responsive homopolymer poly(N-isopropylacrylamide) or the random copolymer poly(N-isopropylacrylamide-co-acrylic acid) as structure-directing agent (SDA) and Na2SiO3 as silica source is proposed. The thermo-responsive character of the SDA provides the advantages including (1) temperature dependent synthesis of microporous silica, hierarchically micro-mesoporous silica, and mesoporous silica just by changing the aging temperature below or above the low critical solution temperature of the thermo-responsive SDA, and (2) elimination of the thermo-responsive SDA from silica matrix by water extraction. The synthesis mechanism is discussed, and the effect of the aging temperature and the weight radio of SDA/Na 2SiO3 on the synthesis of micro- and meso-porous silica are studied. Microporous silica, hierarchically micro-mesoporous silica and mesoporous silica with the surface area at 3.5-9.0 × 102 m 2/g and the pore volume at 0.28-1.13 cm3/g and the average pore size ranging from 1.1 to 9.0 nm are synthesized. The strategy affords a new and environmentally benign way to fabricate porous silica materials, and is believed to bridge the gap between the synthesis of microporous and mesoporous silica materials. © 2011 Springer Science+Business Media, LLC. Source

Ma T.-Y.,Institute of New Catalytic Materials Science | Ma T.-Y.,Nankai University | Yuan Z.-Y.,Institute of New Catalytic Materials Science | Yuan Z.-Y.,Nankai University
European Journal of Inorganic Chemistry

Organic-inorganic hybrid materials of meso-/mac:roporous titanium triphosphonate materials were synthesized by using amino tri(methylene phosphonic acid) as the coupling molecule. The preparation was accomplished by a hydrothermal process in the presence or absence of small amounts of the diblock copolymer BO30PO34 and ß-cyclodextrin as the organic additives. The organic-additive-assisted preparation efficiently aided the enlargement of the surface areas and pore volumes of the resultant porous titanium triphosphonates and helped improve the wormhole-like mesoporosity. In addition to the large macrochannels, with a size of 500-1000 nm, observed in all the titanium phosphonates synthesized with or without organic additives, a secondary smallscaled, spherical macroporous structure with a diameter of 50-100 nm was obtained by the addition of cyclodextrin. These macroporous structures are proposed to be templated by the aggregation of cyclodextrin. The structural characterization confirms the integrity of organic groups inside the framework. Large adsorption capacities for heavy metal ions and CO2 are demonstrated in these hybrid materials, which makes them promising adsorbents for practical applications. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Shao G.-S.,Institute of New Catalytic Materials Science | Liu L.,Institute of New Catalytic Materials Science | Ma T.-Y.,Institute of New Catalytic Materials Science | Wang F.-Y.,Institute of New Catalytic Materials Science | And 2 more authors.
Chemical Engineering Journal

Carbon-modified TiO2 photocatalysts with a hierarchical meso-/macroporous structure were prepared through direct hydrolyzation of n-tetrabutyl titanate in the dodecylamine solution and subsequent calcination under nitrogen atmosphere. The resulting photocatalysts were characterized by X-ray diffraction, scanning and transmission electron microscopy, nitrogen sorption analysis, X-ray photoelectron spectroscopy, and UV-vis spectroscopy. A well-defined hierarchical macrochannel-like structure of mesoporous nanoparticle assembly with a predominant anatase phase was observed in the synthesized carbon-modified titania materials, exhibiting obviously high absorption in the wavelength range of 400-800 nm. It is revealed that carbon could not only substitute partly Ti in the form of Ti-O-C bond but also substitute O in the form of O-Ti-C, besides amorphous interstitial carbon atoms were synchronously introduced, benefitting the improvement of solar light photocatalytic activity. The synthesized hierarchical carbon-modified titanias materials exhibited excellent photocatalytic performance in the photodegradation of Rhodamine B dye, suggesting their promising potential as effective solar photocatalysts for organic waste degradation. © 2010 Elsevier B.V. All rights reserved. Source

Jia A.,Institute of New Catalytic Materials Science | Su Z.,Institute of New Catalytic Materials Science | Lou L.-L.,Institute of New Catalytic Materials Science | Liu S.,Institute of New Catalytic Materials Science
Solid State Sciences

A series of highly-active nickel and lanthanum co-doped SrTiO3 photocatalysts were synthesized via sol-gel process and their photocatalytic activities were evaluated by degradation of methylene blue (MB). The obtained samples were found by XRD, XPS and UV-vis to have a perovskite structure in which Ni and La atoms were incorporated into SrTiO3. After Ni and La doped into SrTiO3, the absorption edge of SrTiO3 powder was greatly shifted from 380 nm to 700 nm. Under a 100 W incandescent lamp irradiating for 14 h, a 100% of MB was degraded, which is much higher than those of pure SrTiO3 and commercial Degussa P25. The optimal range of Ni and La dopants is 0.1-1.0 mol%. The formation of a new absorption edge and the large surface area may be the main reasons for the high activity. © 2010 Elsevier Masson SAS. All rights reserved. Source

Wu Z.,Institute of New Catalytic Materials Science | Wu Z.,Nankai University | Sun C.,Institute of New Catalytic Materials Science | Sun C.,Nankai University | And 4 more authors.
RSC Advances

A magnetic core-shell nanocomposite, Fe 3O 4@SiO 2@Pd-Au, was synthesized by reducing palladium and gold cations previously bound to the amine ligand-modified surface of silica-encapsulated magnetic iron oxide (Fe 3O 4) nanoparticles, and served as a highly efficient and easily-recyclable catalyst for liquid-phase hydrodechlorination of 4-chlorophenol under mild conditions. © 2011 The Royal Society of Chemistry. Source

Discover hidden collaborations