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Buoyant photocatalyst with greatly enhanced visible-light activity prepared through a low temperature hydrothermal method / Hui Han in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2891–2898 Titre : Buoyant photocatalyst with greatly enhanced visible-light activity prepared through a low temperature hydrothermal method Type de document : texte imprimé Auteurs : Hui Han, Auteur ; Renbi Bai, Auteur Année de publication : 2009 Article en page(s) : pp. 2891–2898 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Buoyant  photocatalyst  TiO2  One-step  process Résumé : In this study, TiO2 was modified and immobilized on polypropylene (PP) granules to prepare buoyant photocatalyst with visible light activity. The TiO2 nano-sol was first prepared from titanium n-butoxide (Ti(OBu)4) in the presence of acetyl acetone (AcAc) or acetic acid (AcOH) as an inhibiting agent and subsequently treated with triethylamine (TEA) under the condition of room temperature. Then, a simple one-step process was utilized for the simultaneous crystallization and immobilization of the treated TiO2 nanoparticles on the PP substrate in a low temperature hydrothermal reactor (150 °C). It was found that the TEA-treated TiO2 nano-sol with AcAc as the inhibiting agent led to high visible light activity for the prepared photocatalyst from the low temperature hydrothermal process. The light absorption edge was up to 800 nm, and the visible light absorption rate reached 32 to 66%, depending on the TEA-treatment time. XRD analysis showed all the TiO2-based photocatalysts having the major crystal structure of anatase and minor of brookite. Raman spectroscopy, however, clearly revealed the existence of the nitrogen-doped composition (i.e., TiO2−xNx) in the photocatalyst with high visible light activity. Experiments conducted for decolorization of methyl orange (MO) dye solutions showed the effectiveness of the prepared novel photocatalyst under both the UV and the visible light. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801362a [article] Buoyant photocatalyst with greatly enhanced visible-light activity prepared through a low temperature hydrothermal method [texte imprimé] / Hui Han, Auteur ; Renbi Bai, Auteur . - 2009 . - pp. 2891–2898. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2891–2898 Mots-clés : Buoyant  photocatalyst  TiO2  One-step  process Résumé : In this study, TiO2 was modified and immobilized on polypropylene (PP) granules to prepare buoyant photocatalyst with visible light activity. The TiO2 nano-sol was first prepared from titanium n-butoxide (Ti(OBu)4) in the presence of acetyl acetone (AcAc) or acetic acid (AcOH) as an inhibiting agent and subsequently treated with triethylamine (TEA) under the condition of room temperature. Then, a simple one-step process was utilized for the simultaneous crystallization and immobilization of the treated TiO2 nanoparticles on the PP substrate in a low temperature hydrothermal reactor (150 °C). It was found that the TEA-treated TiO2 nano-sol with AcAc as the inhibiting agent led to high visible light activity for the prepared photocatalyst from the low temperature hydrothermal process. The light absorption edge was up to 800 nm, and the visible light absorption rate reached 32 to 66%, depending on the TEA-treatment time. XRD analysis showed all the TiO2-based photocatalysts having the major crystal structure of anatase and minor of brookite. Raman spectroscopy, however, clearly revealed the existence of the nitrogen-doped composition (i.e., TiO2−xNx) in the photocatalyst with high visible light activity. Experiments conducted for decolorization of methyl orange (MO) dye solutions showed the effectiveness of the prepared novel photocatalyst under both the UV and the visible light. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801362a

Coating of TiO2 Thin Films on the Surface of SiO2 Microspheres: Toward Industrial Photocatalysis / Gang Li in Industrial & engineering chemistry research, Vol. 47 n°21 (Novembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p 8228–8232 Titre : Coating of TiO2 Thin Films on the Surface of SiO2 Microspheres: Toward Industrial Photocatalysis Type de document : texte imprimé Auteurs : Gang Li, Auteur ; Renbi Bai, Auteur ; X. S. Zhao, Auteur Année de publication : 2008 Article en page(s) : p 8228–8232 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Surface  of  SiO2  Treating  wastewater. Résumé : A core/shell SiO2/TiO2 photocatalyst was prepared using a liquid-phase deposition (LPD) method. Zeta-potential measurement showed that deposition of a layer of polyelectrolyte on the surface of SiO2 microspheres was a prerequisite for subsequent deposition of the TiO2 shell with a controllable and uniform thickness. The photocatalytic activity of the core/shell SiO2/TiO2 catalyst for decomposition of Orange II in liquid phase was observed to be comparable with that of P25 (a commercial TiO2 product of Degussa). Experimental data also showed that the SiO2/TiO2 core/shell nanostructured photocatalyst can be easily separated from the reaction medium by sedimentation, and the solid can be recycled and reused. Thus, the photocatalyst described in this work represents a new catalyst system with a high potential for practical applications in treating wastewater. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800561y [article] Coating of TiO2 Thin Films on the Surface of SiO2 Microspheres: Toward Industrial Photocatalysis [texte imprimé] / Gang Li, Auteur ; Renbi Bai, Auteur ; X. S. Zhao, Auteur . - 2008 . - p 8228–8232. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p 8228–8232 Mots-clés : Surface  of  SiO2  Treating  wastewater. Résumé : A core/shell SiO2/TiO2 photocatalyst was prepared using a liquid-phase deposition (LPD) method. Zeta-potential measurement showed that deposition of a layer of polyelectrolyte on the surface of SiO2 microspheres was a prerequisite for subsequent deposition of the TiO2 shell with a controllable and uniform thickness. The photocatalytic activity of the core/shell SiO2/TiO2 catalyst for decomposition of Orange II in liquid phase was observed to be comparable with that of P25 (a commercial TiO2 product of Degussa). Experimental data also showed that the SiO2/TiO2 core/shell nanostructured photocatalyst can be easily separated from the reaction medium by sedimentation, and the solid can be recycled and reused. Thus, the photocatalyst described in this work represents a new catalyst system with a high potential for practical applications in treating wastewater. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800561y

Effect of thickness of photocatalyst film immobilized on a buoyant substrate on the degradation of methyl orange dye in aqueous solutions under different light irradiations / Hui Han in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11922-11929 Titre : Effect of thickness of photocatalyst film immobilized on a buoyant substrate on the degradation of methyl orange dye in aqueous solutions under different light irradiations Type de document : texte imprimé Auteurs : Hui Han, Auteur ; Renbi Bai, Auteur Année de publication : 2011 Article en page(s) : pp. 11922-11929 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous  solution  Dyes  Photocatalysis  Catalyst Résumé : This study examined the effect of thickness of photocatalyst film immobilized on a buovant polypropylene (PP) substrate on the degradation of methyl orange (MO) dye in aqueous solutions using different light sources. The photocatalyst used was titanium dioxide (TiO2) and the immobilized photocatalyst film thickness varied in a range from 6.9 to 34.1 μm. Both degradation experiments and model fitting analysis for the experimental data were carried out. All the experimental results on MO dye degradation were found to be well fitted by a pseudo-first-order reaction kinetic model. However, the degradation performance and the reaction kinetic model rate constant showed a clear trend of increase with the increase of the photocatalyst film thickness under the visible (Vis) light irradiation, but had no obvious change with the photocatalyst film thickness under the ultraviolet (UV) light irradiation. This phenomenon was attributed to the much smaller active photocatalyst film thickness for the UV light (due to the lesser quantity of photons and hence less thickness through which the light penetrated), as compared to that for the Vis light in the photocatalytic reaction. The study reveals that methods effectively increasing the photocatalyst film thickness on the buoyant substrate in the preparation of the buoyant composite photocatalyst are beneficial for the photocatalytic degradation of MO dye, especially for situations when the system may work mainly with the visible light, such as using the natural sunlight as the light source. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697509 [article] Effect of thickness of photocatalyst film immobilized on a buoyant substrate on the degradation of methyl orange dye in aqueous solutions under different light irradiations [texte imprimé] / Hui Han, Auteur ; Renbi Bai, Auteur . - 2011 . - pp. 11922-11929. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11922-11929 Mots-clés : Aqueous  solution  Dyes  Photocatalysis  Catalyst Résumé : This study examined the effect of thickness of photocatalyst film immobilized on a buovant polypropylene (PP) substrate on the degradation of methyl orange (MO) dye in aqueous solutions using different light sources. The photocatalyst used was titanium dioxide (TiO2) and the immobilized photocatalyst film thickness varied in a range from 6.9 to 34.1 μm. Both degradation experiments and model fitting analysis for the experimental data were carried out. All the experimental results on MO dye degradation were found to be well fitted by a pseudo-first-order reaction kinetic model. However, the degradation performance and the reaction kinetic model rate constant showed a clear trend of increase with the increase of the photocatalyst film thickness under the visible (Vis) light irradiation, but had no obvious change with the photocatalyst film thickness under the ultraviolet (UV) light irradiation. This phenomenon was attributed to the much smaller active photocatalyst film thickness for the UV light (due to the lesser quantity of photons and hence less thickness through which the light penetrated), as compared to that for the Vis light in the photocatalytic reaction. The study reveals that methods effectively increasing the photocatalyst film thickness on the buoyant substrate in the preparation of the buoyant composite photocatalyst are beneficial for the photocatalytic degradation of MO dye, especially for situations when the system may work mainly with the visible light, such as using the natural sunlight as the light source. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697509