Mechanochemical transformation of an organic ligand on mineral surfaces: the efficiency of birnessite in catechol degradation
Abstract
The aim of this work is to investigate the efficiency of the phyllomanganate birnessite in degrading catechol after mechanochemical treatments. A synthesized birnessite and the organic molecule were grounded together in a high energy mill and the xenobiotic-mineral surface reactions induced by the grinding treatment have been investigated by means of X-ray powder diffraction, X-ray fluorescence, thermal analysis and spectroscopic techniques as well as high-performance liquid chromatography and voltammetric techniques. If compared to the simple contact between the birnessite and the organic molecule, mechanochemical treatments have revealed to be highly efficient in degrading catechol molecules, in terms both of time and extent. Due to the two phenolic groups of catechol and the small steric hindrance of the molecule, the extent of the mechanochemically induced degradation of catechol onto birnessite surfaces is quite high. The degradation mechanism mainly occurs via a redox reaction. It implies the formation of a surface bidentate inner-sphere complex between the phenolic group of the organic molecules and the Mn(IV) from the birnessite structure. Structural changes occur on the MnO6 layers of birnessite as due to the mechanically induced surface reactions: reduction of Mn(IV), consequent formation of Mn(III) and new vacancies, and free Mn2+ ions production.
Autore Pugliese
Tutti gli autori
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SCHINGARO E.;MESTO E.;VENTRUTI G.;PIZZIGALLO M.
Titolo volume/Rivista
Non Disponibile
Anno di pubblicazione
2012
ISSN
0304-3894
ISBN
Non Disponibile
Numero di citazioni Wos
Nessuna citazione
Ultimo Aggiornamento Citazioni
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Numero di citazioni Scopus
12
Ultimo Aggiornamento Citazioni
Non Disponibile
Settori ERC
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Codici ASJC
Non Disponibile
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