Heterogeneous photocatalysis of oxalic acid, phenol and coumarin-detailed investigation of the effect of reaction parameters

In the case of heterogeneous photocatalysis the transformation of organic compounds can take place due to the hydroxil radical (HO) based reactions or direct charge transfer on the surface of the photocatalyst. The relative contribution of these ways to the transformation depends strongly on the ch...

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Bibliographic Details
Main Authors: Molnár Milán
Náfrádi Máté
Schrantz Krisztina
Hernádi Klára
Alapi Tünde
Corporate Author: International Symposium on Analytical and Environmental Problems (23.) (2017) (Szeged)
Format: Book part
Published: 2017
Series:Proceedings of the International Symposium on Analytical and Environmental Problems 23
Kulcsszavak:Analitikai kémia, Környezetkémia, Szervetlen kémia, Fotokatalízis
Online Access:http://acta.bibl.u-szeged.hu/56259
Description
Summary:In the case of heterogeneous photocatalysis the transformation of organic compounds can take place due to the hydroxil radical (HO) based reactions or direct charge transfer on the surface of the photocatalyst. The relative contribution of these ways to the transformation depends strongly on the chemical properties of the pollutant, and the surface properties of the photocatalys, which can be strongly influenced by the properties of the solution, such as pH, ionic straight, etc. In the present work the effect of various reaction parameters (methanol as non-adsorbed HO scavenger, formic acid and Na-formiate as well adsorbed HO scavengers, NaF as surface modifier, EDTA and pH) were studied on the transformation of the phenol, oxalic acid and coumatin. The transformation of the phenol, which does not adsorbed well on the TiO2 surface is mainly takes place by HO based reaction, which was confirmed by the effect of HO scavengers. Oxalic acid adsorbed well and mainly the direct charge transfer is responsible for its transformation. The negligible effect of methanol and significant negative effect of NaF on zhe rate of transformation confirmed this. The relative contribution of the HO based reaction and direct charge transfer to the transformation of coumarin depended strongly on the reaction parameters, such as pH and the presence of additives.
Physical Description:502-506
ISBN:978-963-306-563-1