Photodegradation comparison for methyl orange by TiO_2, H_2O_2 and KIO_4

摘要

The photodegradation of methyl orange in water by the catalyst TiO2 or the oxidants (H2O2, KIO4) or their combination (TiO2 + H2O2, TiO2 + KIO4) under UV light illumination is studied. During the above process, as far as the photodiscoloration degree of methyl orange is concerned, the effect sequence is KIO4 + TiO2 KIO4 TiO2 + H2O2 TiO2 H2O2; as far as the photomineralization degree of methyl orange is concerned, the effect sequence is TiO2 approximate to TiO2 + H2O2 H2O2 KIO4 + TiO2 KIO4; as for the catalysis of TiO2, h(+) plays more important role than HO center dot, the inorganic ions (, , , ) are generated, especially for the amount of . Active HO center dot is generated, we can measure HO center dot by terephthalic acid (TA) indirectly: TA reacts with HO center dot to form highly fluorescent product, namely 2-hydroxyterephthalic acid (TAOH).[GRAPHICS].