Alternative natural dyes in water purification: Anthocyanin as TiO2-sensitizer in methyl orange photo-degradation
Langue
en
Article de revue
Ce document a été publié dans
Solid State Sciences. 2011, vol. 13, n° 6, p. 1268-1275
Elsevier
Résumé en anglais
Natural molecular dye, anthocyanin, is described here as safe sensitizer for TiO<sub>2</sub> particles in photo-degradation of organic contaminants in water. The dye is a promising replacement for the more costly and ...Lire la suite >
Natural molecular dye, anthocyanin, is described here as safe sensitizer for TiO<sub>2</sub> particles in photo-degradation of organic contaminants in water. The dye is a promising replacement for the more costly and hazardous heavy metal based systems, such as CdS particles and Ru-compounds. TiO<sub>2</sub>/anthocyanin effectively catalyzed the photo-degradation of methyl orange contaminant under solar simulator radiation. The new TiO<sub>2</sub>/anthocyanin catalyst showed comparable efficiency to earlier systems, while avoiding their hazardous nature. When supported onto activated carbon (AC) particles, the resulting AC/TiO<sub>2</sub>/anthocyanin system showed enhanced efficiency and ease of recovery from the catalytic reaction mixture. The natural dye molecules showed the tendency to degrade under photo-degradation conditions, just like earlier hazardous sensitizers. However, complete mineralization of anthocyanin occurred leaving no traces of organic species in solution. Sensitizer degradation caused deactivation of the supported catalyst on recovery. Such a shortcoming was overcome by re-treatment of the recovered catalysts with fresh dye. Effects of different reaction parameters on the catalyst efficiency were studied. A mechanism, similar to earlier CdS-sensitized catalyst systems, is proposed for the TiO<sub>2</sub>/anthocyanin catalyst.< Réduire
Mots clés en anglais
Natural dyes
Athocyanin
Photo-degradation
Solar simulato r
Methyl orange
Water
Origine
Importé de halUnités de recherche