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Porphyrin-nanoclay photosensitizers for visible light induced oxidation of phenol in aqueous media
A new type of hybrid photosensitizer (Po-C30B) was obtained by efficient adsorption of a 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (Po) by Cloisite 30B (C30B)-a monotallow bis(hydroxyethyl)ammonium-modified montmorillonite clay-from acidic solution in methanol. Structural and spectroscopic properties of Po-nanoclay photosensitizer were determined using X-ray diffraction, laser scanning fluorescence confocal microscopy, and electronic absorption/emission spectroscopies. Po is present not only at the surface of the nanoclay but also in the interior of the Po-C30B hybrid material. The obtained material was found to be an efficient photosensitizer for the oxidation of phenol in aqueous solution under irradiation with the visible light (λ > 470 nm). The mechanism and the quantum yield of that process were shown to be strongly pH-dependent. They were controlled by the acid-base equilibria of porphyrin associated with imine N-protonation as well as by the ionization of the phenol molecule. The quantitative information regarding these dependencies was obtained. The values of K3 and K4 acid-base equilibrium constants were determined (pK3 = 5.88 and pK4 = 2.46) from the absorption spectra recorded during acid-base titration and using an evolutionary factor analysis with the mathematical model including dicationic (H2Po2+), monocationic (HPo+), and neutral (Po) porphyrin forms. They were used to evaluate the importance of these forms in singlet oxygen generation by Po-C30B under defined pH conditions. Moreover, the hybrid photosensitizer can be used repeatedly, which makes it possible to use it in industrial applications.
dc.abstract.en | A new type of hybrid photosensitizer (Po-C30B) was obtained by efficient adsorption of a 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (Po) by Cloisite 30B (C30B)-a monotallow bis(hydroxyethyl)ammonium-modified montmorillonite clay-from acidic solution in methanol. Structural and spectroscopic properties of Po-nanoclay photosensitizer were determined using X-ray diffraction, laser scanning fluorescence confocal microscopy, and electronic absorption/emission spectroscopies. Po is present not only at the surface of the nanoclay but also in the interior of the Po-C30B hybrid material. The obtained material was found to be an efficient photosensitizer for the oxidation of phenol in aqueous solution under irradiation with the visible light (λ > 470 nm). The mechanism and the quantum yield of that process were shown to be strongly pH-dependent. They were controlled by the acid-base equilibria of porphyrin associated with imine N-protonation as well as by the ionization of the phenol molecule. The quantitative information regarding these dependencies was obtained. The values of K3 and K4 acid-base equilibrium constants were determined (pK3 = 5.88 and pK4 = 2.46) from the absorption spectra recorded during acid-base titration and using an evolutionary factor analysis with the mathematical model including dicationic (H2Po2+), monocationic (HPo+), and neutral (Po) porphyrin forms. They were used to evaluate the importance of these forms in singlet oxygen generation by Po-C30B under defined pH conditions. Moreover, the hybrid photosensitizer can be used repeatedly, which makes it possible to use it in industrial applications. | pl |
dc.affiliation | Wydział Chemii : Zakład Chemii Fizycznej i Elektrochemii | pl |
dc.affiliation | Wydział Biologii i Nauk o Ziemi : Instytut Nauk Geologicznych | pl |
dc.contributor.author | Drozd, Dominik - 126113 | pl |
dc.contributor.author | Szczubiałka, Krzysztof - 132218 | pl |
dc.contributor.author | Skiba, Michał - 131897 | pl |
dc.contributor.author | Kępczyński, Mariusz - 128750 | pl |
dc.contributor.author | Nowakowska, Maria - 131048 | pl |
dc.date.accessioned | 2015-01-16T10:43:58Z | |
dc.date.available | 2015-01-16T10:43:58Z | |
dc.date.issued | 2014 | pl |
dc.description.number | 17 | pl |
dc.description.physical | 9196-9202 | pl |
dc.description.volume | 118 | pl |
dc.identifier.doi | 10.1021/jp500024h | pl |
dc.identifier.eissn | 1932-7455 | pl |
dc.identifier.issn | 1932-7447 | pl |
dc.identifier.uri | http://ruj.uj.edu.pl/xmlui/handle/item/2570 | |
dc.language | eng | pl |
dc.language.container | eng | pl |
dc.rights.licence | bez licencji | |
dc.subtype | Article | pl |
dc.title | Porphyrin-nanoclay photosensitizers for visible light induced oxidation of phenol in aqueous media | pl |
dc.title.journal | The Journal of Physical Chemistry. C | pl |
dc.type | JournalArticle | pl |
dspace.entity.type | Publication |