Title: Photocatalytic Degradation of Malachite Green Dyes With TiO2/WO3 Composite
Abstract:This study summarizes briefly the sources of Malachite green contamination and the wide range of its toxic effects. The photodegradation of this cationic triphenylmethane dye by TiO 2 and TiO 2 /WO 3 ...This study summarizes briefly the sources of Malachite green contamination and the wide range of its toxic effects. The photodegradation of this cationic triphenylmethane dye by TiO 2 and TiO 2 /WO 3 composite is examined under different experimental conditions. Two types of salts - oxalate and hydrochloride were studied and unexpectedly different kinetics of degradation was observed in the presence of TiO 2 or TiO 2 /WO 3 as photocatalysts. The behavior of the hydrochloride dye is almost identical in the presence of both catalysts TiO 2 or TiO 2 /WO 3 , showing equal rates of degradation. However for the oxalate form the TiO 2 /WO 3 composite is significantly more efficient than pure TiO 2 . Even more, the apparent rate constant of degradation for oxalate is higher than that obtained for hydrochloride with the same composite TiO 2 /WO 3 . It is suggested that initial adsorption of the dye on the surface of the catalyst plays important role and explains the different photocatalytic performance of TiO 2 /WO 3 composite powder. Most probably the sorption of Malachite green oxalate is favored by the C 2 O 4 2- ions, this way providing direct photooxidation of the dye. It is also established by UV-VIS comparative analysis that during the proposed photopurification of the pollutants the formation of the colorless carcinogenic Leuco malachite green is negligible.Read More
Publication Year: 2008
Publication Date: 2008-01-01
Language: en
Type: article
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Cited By Count: 10
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