Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspension
The reaction of electrons stored on TiO2 nanoparticles with heavy metal ions Hg (II), Ni (II) and Pb (II) has been studied employing steady state and stopped flow spectrophotometric techniques. Prior to kinetic investigation the formation of metal deposits is detected by their surface Plasmon absorb...
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| Format: | Article |
| Language: | English |
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Elsevier
2019-12-01
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| Series: | Arabian Journal of Chemistry |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1878535216301216 |
| _version_ | 1818187595643879424 |
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| author | Hanan H. Mohamed Nuhad A. Alomair Detlef W. Bahnemann |
| author_facet | Hanan H. Mohamed Nuhad A. Alomair Detlef W. Bahnemann |
| author_sort | Hanan H. Mohamed |
| collection | DOAJ |
| description | The reaction of electrons stored on TiO2 nanoparticles with heavy metal ions Hg (II), Ni (II) and Pb (II) has been studied employing steady state and stopped flow spectrophotometric techniques. Prior to kinetic investigation the formation of metal deposits is detected by their surface Plasmon absorbance observed after mixing of their corresponding metal ions with stored electron on TiO2 nanoparticles (eTiO2-). The dynamic of transfer of stored TiO2 electrons to Hg (II), Pb (II) and Ni (II) in water has been investigated after mixing in the stopped flow chamber following the decrease of the absorbance of eTiO2- at 600 nm. The results indicate that Hg (II), Pb (II) and Ni (II) ions react readily with eTiO2-. The kinetic parameters of the electron transfer reactions have been obtained by pseudo first order fitting. In the presence of Hg (II) ions, the transients decay followed by a buildup at 380–480 nm range. In the presence of Pb (II) and Ni (II), a concurrent decay of TiO2 electron absorbance and buildup of the absorbance of metal deposits were observed. The rate constants of the electron transfer reactions induced by TiO2 stored electrons to metal ions increase with the driving force of the reaction according to Tafel equation. Keywords: TiO2 nanoparticles, Stored electrons, Hazardous metal ions, Kinetics, Mechanism |
| first_indexed | 2024-12-11T23:13:32Z |
| format | Article |
| id | doaj.art-ecbc2c72263a458e97bed31b37307702 |
| institution | Directory Open Access Journal |
| issn | 1878-5352 |
| language | English |
| last_indexed | 2024-12-11T23:13:32Z |
| publishDate | 2019-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Arabian Journal of Chemistry |
| spelling | doaj.art-ecbc2c72263a458e97bed31b373077022022-12-22T00:46:38ZengElsevierArabian Journal of Chemistry1878-53522019-12-0112851345141Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspensionHanan H. Mohamed0Nuhad A. Alomair1Detlef W. Bahnemann2Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, 11719 Cairo, Egypt; Corresponding author.Department of Chemistry, College of Science, University of Dammam, P.O. Box 1982, Dammam 31441, Saudi ArabiaInstitut fuer Technische Chemie, Gottfried Wilhelm Leibniz Universitaet Hannover, Callinstrasse 3, D-30167 Hannover, Germany; Saint-Petersburg State University, Laboratory ‘‘Photoactive Nanocomposite Materials’’, Saint-Petersburg 198504, RussiaThe reaction of electrons stored on TiO2 nanoparticles with heavy metal ions Hg (II), Ni (II) and Pb (II) has been studied employing steady state and stopped flow spectrophotometric techniques. Prior to kinetic investigation the formation of metal deposits is detected by their surface Plasmon absorbance observed after mixing of their corresponding metal ions with stored electron on TiO2 nanoparticles (eTiO2-). The dynamic of transfer of stored TiO2 electrons to Hg (II), Pb (II) and Ni (II) in water has been investigated after mixing in the stopped flow chamber following the decrease of the absorbance of eTiO2- at 600 nm. The results indicate that Hg (II), Pb (II) and Ni (II) ions react readily with eTiO2-. The kinetic parameters of the electron transfer reactions have been obtained by pseudo first order fitting. In the presence of Hg (II) ions, the transients decay followed by a buildup at 380–480 nm range. In the presence of Pb (II) and Ni (II), a concurrent decay of TiO2 electron absorbance and buildup of the absorbance of metal deposits were observed. The rate constants of the electron transfer reactions induced by TiO2 stored electrons to metal ions increase with the driving force of the reaction according to Tafel equation. Keywords: TiO2 nanoparticles, Stored electrons, Hazardous metal ions, Kinetics, Mechanismhttp://www.sciencedirect.com/science/article/pii/S1878535216301216 |
| spellingShingle | Hanan H. Mohamed Nuhad A. Alomair Detlef W. Bahnemann Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspension Arabian Journal of Chemistry |
| title | Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspension |
| title_full | Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspension |
| title_fullStr | Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspension |
| title_full_unstemmed | Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspension |
| title_short | Kinetic and mechanistic features on the reaction of stored TiO2 electrons with Hg (II), Pb (II) and Ni (II) in aqueous suspension |
| title_sort | kinetic and mechanistic features on the reaction of stored tio2 electrons with hg ii pb ii and ni ii in aqueous suspension |
| url | http://www.sciencedirect.com/science/article/pii/S1878535216301216 |
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