Dosage de traces de chrome hexavalent par voie photoélectrochimique

Abstract : Hexavalent chromium is toxic even at a very low concentration. His detection require many processes of separation and preconcentration before analyzing the sample. This study describes the elaboration of a new method of Cr(VI) determination with a specific, selective and accurate detection and without manipulating the sample. The electrochemical probe is mabe by TiO2 single crystal n doped by partial reduction of rutile in hydrogen. The obtained semiconductor of the n doped rutile are deduced from impedance spectra of In-Ga/TiO2x/Au Schottky diode. This method has allowed us to suggest the reduction kenitic of rutile in hydrogen. After the activation in an electrolytic solution, the semiconductor is used as a photoelectrochemical sensor. The Cr(VI) concentration is measured in three steps : accumulation of the chromium at the surface of rutile at open circuit, voltametric sweeping with UV illumination of the electrode and surface regeneration. The detection is quantitative between 0.005 and 2 ppm without any perturbation by other ions
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Theses
File URL :
http://docnum.univ-lorraine.fr/prive/INPL_T_1997_BEN_FARAH_M.pdf
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https://hal.univ-lorraine.fr/tel-01752319
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Submitted on : Thursday, March 29, 2018 - 1:40:55 PM
Last modification on : Thursday, January 31, 2019 - 1:27:49 AM

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  • HAL Id : tel-01752319, version 1

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Moez Ben Farah. Dosage de traces de chrome hexavalent par voie photoélectrochimique. Autre. Institut National Polytechnique de Lorraine, 1997. Français. ⟨NNT : 1997INPL134N⟩. ⟨tel-01752319⟩

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