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Photocatalytic degradation of acetone over sulfated MoOx/MgF2 composite / Yiming He in Industrial & engineering chemistry research, Vol. 50 N° 12 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7109-7119 Titre : Photocatalytic degradation of acetone over sulfated MoOx/MgF2 composite : effect of molybdenum concentration and calcination temperature Type de document : texte imprimé Auteurs : Yiming He, Auteur ; Leihong Zhao, Auteur ; Yongjiao Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 7109-7119 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Calcining  Composite  material  Photochemical  degradation Résumé : This paper presents a novel visible-light-driven catalyst, a SO42―/MoOx/MgF2 composite, which was synthesized by a simple solution method. Multiple techniques, including Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS) were applied to investigate the physical and photophysical properties of the catalysts. The photocatalytic activities were evaluated in the degradation of acetone in gas phase. In the photodegradation of acetone, the highest conversion was obtained over a catalyst containing 5 mol % molybdenum. The XRD and Raman characterizations indicate that the molybdenum oxide was highly dispersed in the MgF2 matrix. These MoOx. species might be the active sites of the catalysts, which is the reason for the visible-light response of the composite catalyst. The MgF2 matrix acts to isolate the MoOx species and retard the electron-hole pair recombination. When the molybdenum concentration is >5 mol %, crystalline MoO3 phase was observed. The large MoO3 particle would decrease the separation efficiency. Thus, the photocatalytic activity was reduced. Besides the molybdenum concentration, the calcination temperature also shows a great effect on the activity. A sulfated 5 mol % MoOx/MgF2 catalyst that was calcined at 350 °C showed the highest photocatalytic activity. Based on the results of the characaterization, the origin of the high activity was discussed. The light absorption ability and the MoOx size effect are considered as the key factors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239024 [article] Photocatalytic degradation of acetone over sulfated MoOx/MgF2 composite : effect of molybdenum concentration and calcination temperature [texte imprimé] / Yiming He, Auteur ; Leihong Zhao, Auteur ; Yongjiao Wang, Auteur . - 2011 . - pp. 7109-7119. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7109-7119 Mots-clés : Calcining  Composite  material  Photochemical  degradation Résumé : This paper presents a novel visible-light-driven catalyst, a SO42―/MoOx/MgF2 composite, which was synthesized by a simple solution method. Multiple techniques, including Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS) were applied to investigate the physical and photophysical properties of the catalysts. The photocatalytic activities were evaluated in the degradation of acetone in gas phase. In the photodegradation of acetone, the highest conversion was obtained over a catalyst containing 5 mol % molybdenum. The XRD and Raman characterizations indicate that the molybdenum oxide was highly dispersed in the MgF2 matrix. These MoOx. species might be the active sites of the catalysts, which is the reason for the visible-light response of the composite catalyst. The MgF2 matrix acts to isolate the MoOx species and retard the electron-hole pair recombination. When the molybdenum concentration is >5 mol %, crystalline MoO3 phase was observed. The large MoO3 particle would decrease the separation efficiency. Thus, the photocatalytic activity was reduced. Besides the molybdenum concentration, the calcination temperature also shows a great effect on the activity. A sulfated 5 mol % MoOx/MgF2 catalyst that was calcined at 350 °C showed the highest photocatalytic activity. Based on the results of the characaterization, the origin of the high activity was discussed. The light absorption ability and the MoOx size effect are considered as the key factors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239024

Synthesis, characterization, and activity evaluation of DyVO4/g-C3N4 composites under visible-light irradiation / Yiming He in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14729-14737 Titre : Synthesis, characterization, and activity evaluation of DyVO4/g-C3N4 composites under visible-light irradiation Type de document : texte imprimé Auteurs : Yiming He, Auteur ; Jun Cai, Auteur ; Tingting Li, Auteur Année de publication : 2013 Article en page(s) : pp. 14729-14737 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Visible  radiation  Composite  material Résumé : DyVO4/graphitic carbon nitride (DyVO4/g-C3N4) composite photocatalyst with visible-light response was prepared by a milling and heating treatment method. The synthesized powder was characterized by X-ray diffraction, thermogravimetry/differential thermal analysis, N2 adsorption, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV―vis diffuse reflection spectroscopy. The activity of composite photocatalyst DyVO4/g-C3N4 for photodegradation of rhodamine B is much higher than that of either single-phase g-C3N4 or DyVO4. The obviously increased performance of DyVO4/g-C3N4 is mainly ascribed to the electron-hole separation enhancement at the interface of the two semiconductors, as proven by photoluminescence spectroscopy and photocurrent measurement. In addition, it is found that holes and •O2― are the main active species in the photocatalytic oxidation of RhB solution in the presence of DyVO4/g-C3N4 composite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620387 [article] Synthesis, characterization, and activity evaluation of DyVO4/g-C3N4 composites under visible-light irradiation [texte imprimé] / Yiming He, Auteur ; Jun Cai, Auteur ; Tingting Li, Auteur . - 2013 . - pp. 14729-14737. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14729-14737 Mots-clés : Visible  radiation  Composite  material Résumé : DyVO4/graphitic carbon nitride (DyVO4/g-C3N4) composite photocatalyst with visible-light response was prepared by a milling and heating treatment method. The synthesized powder was characterized by X-ray diffraction, thermogravimetry/differential thermal analysis, N2 adsorption, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV―vis diffuse reflection spectroscopy. The activity of composite photocatalyst DyVO4/g-C3N4 for photodegradation of rhodamine B is much higher than that of either single-phase g-C3N4 or DyVO4. The obviously increased performance of DyVO4/g-C3N4 is mainly ascribed to the electron-hole separation enhancement at the interface of the two semiconductors, as proven by photoluminescence spectroscopy and photocurrent measurement. In addition, it is found that holes and •O2― are the main active species in the photocatalytic oxidation of RhB solution in the presence of DyVO4/g-C3N4 composite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620387