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Effective enhancement of the degradation of oxalic acid by catalytic ozonation with TiO2 by exposure of {001} facets and surface fluorination / Zhiqiao He in Industrial & engineering chemistry research, Vol. 51 N° 16 (Avril 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5662–5668 Titre : Effective enhancement of the degradation of oxalic acid by catalytic ozonation with TiO2 by exposure of {001} facets and surface fluorination Type de document : texte imprimé Auteurs : Zhiqiao He, Auteur ; Qiaolan Cai, Auteur ; Fangyue Hong, Auteur Année de publication : 2012 Article en page(s) : pp. 5662–5668 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation  Oxalic  acid  Catalytic  ozonation Résumé : Heterogeneous catalytic ozonation is a promising advanced oxidation technology for water treatment. In the present work, the surface fluorination of TiO2 catalysts with a high percentage of exposed {001} facets (F-TiO2) were synthesized through a hydrothermal method using tetrabutyl titanate as the precursor and HF as the shape controlling agent. The structural properties of the catalysts were characterized by X-ray diffraction, the Brunauer–Emmett–Teller method, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The sheetlike TiO2 is pure anatase, with 75% of highly reactive {001} facets. The surface fluoride of the F-TiO2 nanosheets can be removed by washing with dilute NaOH solution (abbreviated here as OH-TiO2), resulting in a decrease of Ti3+ content and an increase of the specific surface area. The catalytic activity of the samples was evaluated by degradation of oxalic acid in aqueous solution in the presence of ozone. It was found that F-TiO2 facilitated the catalytic ozonation process by comparison with OH-TiO2 and pure TiO2 nanoparticles prepared in pure water. We conclude that the high surface energies of {001} facets and the increased concentration of oxygen vacancies contributed to the enhancement of the ozonation activity of fluorinated TiO2 with dominant {001} facets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202357d [article] Effective enhancement of the degradation of oxalic acid by catalytic ozonation with TiO2 by exposure of {001} facets and surface fluorination [texte imprimé] / Zhiqiao He, Auteur ; Qiaolan Cai, Auteur ; Fangyue Hong, Auteur . - 2012 . - pp. 5662–5668. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5662–5668 Mots-clés : Oxidation  Oxalic  acid  Catalytic  ozonation Résumé : Heterogeneous catalytic ozonation is a promising advanced oxidation technology for water treatment. In the present work, the surface fluorination of TiO2 catalysts with a high percentage of exposed {001} facets (F-TiO2) were synthesized through a hydrothermal method using tetrabutyl titanate as the precursor and HF as the shape controlling agent. The structural properties of the catalysts were characterized by X-ray diffraction, the Brunauer–Emmett–Teller method, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The sheetlike TiO2 is pure anatase, with 75% of highly reactive {001} facets. The surface fluoride of the F-TiO2 nanosheets can be removed by washing with dilute NaOH solution (abbreviated here as OH-TiO2), resulting in a decrease of Ti3+ content and an increase of the specific surface area. The catalytic activity of the samples was evaluated by degradation of oxalic acid in aqueous solution in the presence of ozone. It was found that F-TiO2 facilitated the catalytic ozonation process by comparison with OH-TiO2 and pure TiO2 nanoparticles prepared in pure water. We conclude that the high surface energies of {001} facets and the increased concentration of oxygen vacancies contributed to the enhancement of the ozonation activity of fluorinated TiO2 with dominant {001} facets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202357d

Ozonation combined with sonolysis for degradation and detoxification of m-nitrotoluene in aqueous solution / Zhiqiao He in Industrial & engineering chemistry research, Vol. 48 N° 12 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5578–5583 Titre : Ozonation combined with sonolysis for degradation and detoxification of m-nitrotoluene in aqueous solution Type de document : texte imprimé Auteurs : Zhiqiao He, Auteur ; Runye Zhu, Auteur ; Xing Xu, Auteur Année de publication : 2009 Article en page(s) : pp. 5578–5583 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Sonolytic  ozonation  Nitroaromatic  compound  m-nitrotoluene  Toxicity  Aqueous  solution Résumé : Sonolytic ozonation (US/O3 oxidation) is an advanced oxidation process that has become a focus of intense investigation. In this study, the nitroaromatic compound m-nitrotoluene (MNT) was chosen as a model substrate for degradation experiments in which pH, initial concentration of MNT, ozone dose, and US density were varied. At pH 10.0, initial concentration of MNT 400 mg/L, ozone dose 2.4 g/h, and US energy density 88 W/L, the efficiency of MNT removal reached 98% after 120 min. Of the initial degradation rate of MNT abatement, 9.8, 4.1, and 1.1 mg/(L min) were observed with US/O3, O3, and US, respectively. The variation of the concentrations of related anions (oxalate, acetate, formate, and nitrate ion) during the reaction process was ascertained by ion chromatography (IC). The major intermediates detected by gas chromatography/mass spectrometry (GC/MS) were 3-nitrobenzaldehyde, 3-nitrobenzoic acid, nitrobenzene, benzene, butene diacid, oxalic acid, and acetic acid. A degradation pathway is proposed on the basis of these findings. The acute toxicity of the reaction solution to zebra fish (Danio rerio) was estimated after US/O3 treatment. According to the decreasing lethal rate during the US/O3 process, it could be deduced that US/O3 is a powerful tool with which to achieve effective reduction of the toxicity of MNT. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801566z [article] Ozonation combined with sonolysis for degradation and detoxification of m-nitrotoluene in aqueous solution [texte imprimé] / Zhiqiao He, Auteur ; Runye Zhu, Auteur ; Xing Xu, Auteur . - 2009 . - pp. 5578–5583. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 12 (Juin 2009) . - pp. 5578–5583 Mots-clés : Sonolytic  ozonation  Nitroaromatic  compound  m-nitrotoluene  Toxicity  Aqueous  solution Résumé : Sonolytic ozonation (US/O3 oxidation) is an advanced oxidation process that has become a focus of intense investigation. In this study, the nitroaromatic compound m-nitrotoluene (MNT) was chosen as a model substrate for degradation experiments in which pH, initial concentration of MNT, ozone dose, and US density were varied. At pH 10.0, initial concentration of MNT 400 mg/L, ozone dose 2.4 g/h, and US energy density 88 W/L, the efficiency of MNT removal reached 98% after 120 min. Of the initial degradation rate of MNT abatement, 9.8, 4.1, and 1.1 mg/(L min) were observed with US/O3, O3, and US, respectively. The variation of the concentrations of related anions (oxalate, acetate, formate, and nitrate ion) during the reaction process was ascertained by ion chromatography (IC). The major intermediates detected by gas chromatography/mass spectrometry (GC/MS) were 3-nitrobenzaldehyde, 3-nitrobenzoic acid, nitrobenzene, benzene, butene diacid, oxalic acid, and acetic acid. A degradation pathway is proposed on the basis of these findings. The acute toxicity of the reaction solution to zebra fish (Danio rerio) was estimated after US/O3 treatment. According to the decreasing lethal rate during the US/O3 process, it could be deduced that US/O3 is a powerful tool with which to achieve effective reduction of the toxicity of MNT. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801566z

Y - Al2O3 modified with praseodymium / Zhiqiao He in Industrial & engineering chemistry research, Vol. 49 N° 24 (Décembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12345–12351 Titre : Y - Al2O3 modified with praseodymium : an application in the heterogeneous catalytic ozonation of succinic acid in aqueous solution Type de document : texte imprimé Auteurs : Zhiqiao He, Auteur ; Angliang Zhang, Auteur ; Shuang Song, Auteur Année de publication : 2011 Article en page(s) : pp.12345–12351 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic  ozonation  Succinic  acid  Aqueous  solution Résumé : In an attempt to utilize ozone effectively, a series of praseodymium-modified γ-Al2O3 (Pr/Al2O3) was prepared via incipient wetness impregnation using Pr(NO3)3·6H2O as the precursor. The structure and properties of the catalysts were studied by X-ray diffraction (XRD) and the Brunauer−Emmett−Teller (BET) method. Catalytic activity was evaluated by monitoring the degradation of succinic acid (SA) in the presence of ozone. The praseodymium modification can effectively enhance the ozonation activity of γ-Al2O3 upon SA removal. Increasing the calcination temperature of Pr/Al2O3 is disadvantageous for the catalytic process, whereas increasing the load of praseodymium is helpful. After three successive cycles, the Pr/Al2O3 catalyst remained stable in the catalytic ozonation of SA. Overall, the initial degradation rate of SA, as well as the saturated adsorption capacity of SA, were found to have a linear relation to changes of the surface hydroxyl groups of the catalyst. On this basis, we conclude that the significant enhancement of SA degradation using Pr/Al2O3 as a catalyst should be because praseodymium, in the form of Pr6O11, promoted the formation of surface hydroxyl groups. Hence, the adsorption was increased, and the degradation rate of SA was enhanced. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101233h [article] Y - Al2O3 modified with praseodymium : an application in the heterogeneous catalytic ozonation of succinic acid in aqueous solution [texte imprimé] / Zhiqiao He, Auteur ; Angliang Zhang, Auteur ; Shuang Song, Auteur . - 2011 . - pp.12345–12351. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12345–12351 Mots-clés : Catalytic  ozonation  Succinic  acid  Aqueous  solution Résumé : In an attempt to utilize ozone effectively, a series of praseodymium-modified γ-Al2O3 (Pr/Al2O3) was prepared via incipient wetness impregnation using Pr(NO3)3·6H2O as the precursor. The structure and properties of the catalysts were studied by X-ray diffraction (XRD) and the Brunauer−Emmett−Teller (BET) method. Catalytic activity was evaluated by monitoring the degradation of succinic acid (SA) in the presence of ozone. The praseodymium modification can effectively enhance the ozonation activity of γ-Al2O3 upon SA removal. Increasing the calcination temperature of Pr/Al2O3 is disadvantageous for the catalytic process, whereas increasing the load of praseodymium is helpful. After three successive cycles, the Pr/Al2O3 catalyst remained stable in the catalytic ozonation of SA. Overall, the initial degradation rate of SA, as well as the saturated adsorption capacity of SA, were found to have a linear relation to changes of the surface hydroxyl groups of the catalyst. On this basis, we conclude that the significant enhancement of SA degradation using Pr/Al2O3 as a catalyst should be because praseodymium, in the form of Pr6O11, promoted the formation of surface hydroxyl groups. Hence, the adsorption was increased, and the degradation rate of SA was enhanced. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101233h