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Flame synthesis of ball-in-shell structured TiO2 nanospheres / Jie Liu in Industrial & engineering chemistry research, Vol. 48 N°2 (Janvier 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) Titre : Flame synthesis of ball-in-shell structured TiO2 nanospheres Type de document : texte imprimé Auteurs : Jie Liu, Auteur ; Yanjie Hu, Auteur ; Feng Gu, Auteur ; Chunzhong Li, Auteur Année de publication : 2009 Note générale : chemical engeneering Langues : Anglais (eng) Mots-clés : Nanosphereselectron  microscopy Résumé : Ball-in-shell structured TiO2 nanospheres were successfully made by flame synthesis—a single-step, continuous, and scalable process. The morphology and structure were systematically characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and N2 sorption. TiO2 nanostructures with good crystalline nature and thermal stability were formed by feeding a titanium tetrachloride and alcohol vapor mixture to a facile diffusion flame. The resultant ball-in-shell spheres were composed of nanocrystallites, with shell thickness and void space width of 30−50 nm and 10−30 nm, respectively. The formation mechanism of ball-in-shell spheres was investigated, depending on the competition between the chemical reaction rate and diffusion rate during the flame process. Furthermore, UV−vis characterization indicates that this structure endows the spheres with higher light absorbance, which may be favorable to design and prepare novel materials with enhanced photocatalytic activities. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800986j [article] Flame synthesis of ball-in-shell structured TiO2 nanospheres [texte imprimé] / Jie Liu, Auteur ; Yanjie Hu, Auteur ; Feng Gu, Auteur ; Chunzhong Li, Auteur . - 2009. chemical engeneering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) Mots-clés : Nanosphereselectron  microscopy Résumé : Ball-in-shell structured TiO2 nanospheres were successfully made by flame synthesis—a single-step, continuous, and scalable process. The morphology and structure were systematically characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and N2 sorption. TiO2 nanostructures with good crystalline nature and thermal stability were formed by feeding a titanium tetrachloride and alcohol vapor mixture to a facile diffusion flame. The resultant ball-in-shell spheres were composed of nanocrystallites, with shell thickness and void space width of 30−50 nm and 10−30 nm, respectively. The formation mechanism of ball-in-shell spheres was investigated, depending on the competition between the chemical reaction rate and diffusion rate during the flame process. Furthermore, UV−vis characterization indicates that this structure endows the spheres with higher light absorbance, which may be favorable to design and prepare novel materials with enhanced photocatalytic activities. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800986j

Self-cleaning films with high transparency based on tiO2 nanoparticles synthesized via flame combustion / Huiting Wang in Industrial & engineering chemistry research, Vol. 49 N° 8 (Avril 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3654–3662 Titre : Self-cleaning films with high transparency based on tiO2 nanoparticles synthesized via flame combustion Type de document : texte imprimé Auteurs : Huiting Wang, Auteur ; Yanjie Hu, Auteur ; Ling Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 3654–3662 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Self-Cleaning  Films  with  High  Transparency  Nanoparticles  Synthesized  Flame  Combustion Résumé : Self-cleaning transparent nanoporous films with high photocatalytic properties were obtained based on the self-assembly of TiO2 nanoparticles synthesized by H2/O2 combustion flames. Films were prepared from multilayer deposition of poly(sodium 4-styrenesulfonate)-treated TiO2 nanoparticles and SiO2 nanoparticles with electrostatic interaction by the adsorption of positively charged poly(diallyldimethylammonium chloride) via layer-by-layer assembly processes. The assembly conditions, such as the pH and concentration of a nanoparticle suspension that cause variation of the surface charge densities, were found to strongly affect the thickness and morphology of multilayer films. TiO2/SiO2 coatings assembled with 10 cycles reach effective photocatalysis with a maximum transmittance of 99.3% as well as a water droplet spreading time as short as 0.29 s. The photodegradation kinetics showed that multilayer films fabricated with 10 cycles are 4 times more active than films assembled with 5 cycles, indicating that flame-synthesized TiO2 with well crystallinity can be used to fabricate high transparent self-cleaning films at suitable assembly conditions. The photocatalytic degradation kinetics dominated by control of the number of assembled cycles was also discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901782w [article] Self-cleaning films with high transparency based on tiO2 nanoparticles synthesized via flame combustion [texte imprimé] / Huiting Wang, Auteur ; Yanjie Hu, Auteur ; Ling Zhang, Auteur . - 2010 . - pp. 3654–3662. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3654–3662 Mots-clés : Self-Cleaning  Films  with  High  Transparency  Nanoparticles  Synthesized  Flame  Combustion Résumé : Self-cleaning transparent nanoporous films with high photocatalytic properties were obtained based on the self-assembly of TiO2 nanoparticles synthesized by H2/O2 combustion flames. Films were prepared from multilayer deposition of poly(sodium 4-styrenesulfonate)-treated TiO2 nanoparticles and SiO2 nanoparticles with electrostatic interaction by the adsorption of positively charged poly(diallyldimethylammonium chloride) via layer-by-layer assembly processes. The assembly conditions, such as the pH and concentration of a nanoparticle suspension that cause variation of the surface charge densities, were found to strongly affect the thickness and morphology of multilayer films. TiO2/SiO2 coatings assembled with 10 cycles reach effective photocatalysis with a maximum transmittance of 99.3% as well as a water droplet spreading time as short as 0.29 s. The photodegradation kinetics showed that multilayer films fabricated with 10 cycles are 4 times more active than films assembled with 5 cycles, indicating that flame-synthesized TiO2 with well crystallinity can be used to fabricate high transparent self-cleaning films at suitable assembly conditions. The photocatalytic degradation kinetics dominated by control of the number of assembled cycles was also discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901782w

Stable core shell Co3Fe7 – CoFe2O4 nanoparticles synthesized via flame spray pyrolysis approach / Yunfeng Li in Industrial & engineering chemistry research, Vol. 51 N° 34 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11157-11162 Titre : Stable core shell Co3Fe7 – CoFe2O4 nanoparticles synthesized via flame spray pyrolysis approach Type de document : texte imprimé Auteurs : Yunfeng Li, Auteur ; Yanjie Hu, Auteur ; Junchao Huo, Auteur Année de publication : 2012 Article en page(s) : pp. 11157-11162 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pyrolysis  Flame  Nanoparticle Résumé : Air stable Co3Fe7―CoFe2O4 nanoparticles have been synthesized via one-step flame spray pyrolysis of a mixture of Fe/Co precursor solution under stronger reducing atmosphere. The as-synthesized nanoparticles with diameters of 20-80 nm showed a typical core shell structure and high stability for being one month in air, whose metallic Co3Fe7 cores were protected against oxidation by a surface shell of about 2―4 nm cobalt iron oxide (CoFe2O4). The ratio of metallic Fe/Co alloy nanoparticles was 7:3. The alloy nanoparticles exhibited enhanced saturation magnetization (126.1 emu/g), compared with flame sprayed iron nanoparticles with the same conditions. The formation process of metallic alloy nanoparticles with core-shell structure was investigated, which included three stages: flame combustion, reducing, and surface oxidation during the flame process. It is reckoned that such a continuous production approach is an effective way to produce the stable Co3Fe7 alloy nanoparticles with high saturation magnetization. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299441 [article] Stable core shell Co3Fe7 – CoFe2O4 nanoparticles synthesized via flame spray pyrolysis approach [texte imprimé] / Yunfeng Li, Auteur ; Yanjie Hu, Auteur ; Junchao Huo, Auteur . - 2012 . - pp. 11157-11162. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11157-11162 Mots-clés : Pyrolysis  Flame  Nanoparticle Résumé : Air stable Co3Fe7―CoFe2O4 nanoparticles have been synthesized via one-step flame spray pyrolysis of a mixture of Fe/Co precursor solution under stronger reducing atmosphere. The as-synthesized nanoparticles with diameters of 20-80 nm showed a typical core shell structure and high stability for being one month in air, whose metallic Co3Fe7 cores were protected against oxidation by a surface shell of about 2―4 nm cobalt iron oxide (CoFe2O4). The ratio of metallic Fe/Co alloy nanoparticles was 7:3. The alloy nanoparticles exhibited enhanced saturation magnetization (126.1 emu/g), compared with flame sprayed iron nanoparticles with the same conditions. The formation process of metallic alloy nanoparticles with core-shell structure was investigated, which included three stages: flame combustion, reducing, and surface oxidation during the flame process. It is reckoned that such a continuous production approach is an effective way to produce the stable Co3Fe7 alloy nanoparticles with high saturation magnetization. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299441

Tin oxide nanowires synthesized via flat flame deposition / Jie Liu in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5584-5588 Titre : Tin oxide nanowires synthesized via flat flame deposition : structures and formation mechanism Type de document : texte imprimé Auteurs : Jie Liu, Auteur ; Yanjie Hu, Auteur ; Feng Gu, Auteur Année de publication : 2011 Article en page(s) : pp. 5584-5588 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Formation  mechanism  Flame Résumé : Premixed atmospheric flat flame deposition is a large-scale composite fabrication method that combined the advantages of flame synthesis and thermal evaporation. The technology has been successfully developed to sythesize SnO2 nanowires. The results showed that the as-prepared SnO2 nanowires with special tips are uniform single crystals, growing along [001] direction. Meanwhile, the growth mechanism of the present novel structure, which is a combination of both a vapor-solid ( VS) growth mechanism and a particle formation mechanism in a flame without any catalyst, is also proposed, Furthermore, the optical property is investigated by photoluminescence (PL) spectroscopy, indicating that such SnO2 nanowires exhibit a much stronger emission peak at 620 nm. More importantly, this approach also provides a new pathway for sequentially engineering one-dimensional nanomaterials. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128681 [article] Tin oxide nanowires synthesized via flat flame deposition : structures and formation mechanism [texte imprimé] / Jie Liu, Auteur ; Yanjie Hu, Auteur ; Feng Gu, Auteur . - 2011 . - pp. 5584-5588. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5584-5588 Mots-clés : Formation  mechanism  Flame Résumé : Premixed atmospheric flat flame deposition is a large-scale composite fabrication method that combined the advantages of flame synthesis and thermal evaporation. The technology has been successfully developed to sythesize SnO2 nanowires. The results showed that the as-prepared SnO2 nanowires with special tips are uniform single crystals, growing along [001] direction. Meanwhile, the growth mechanism of the present novel structure, which is a combination of both a vapor-solid ( VS) growth mechanism and a particle formation mechanism in a flame without any catalyst, is also proposed, Furthermore, the optical property is investigated by photoluminescence (PL) spectroscopy, indicating that such SnO2 nanowires exhibit a much stronger emission peak at 620 nm. More importantly, this approach also provides a new pathway for sequentially engineering one-dimensional nanomaterials. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128681