Solar-light induced photodecolorization of water soluble azo-azomethine dye: influence of operational parameters and nanophotocatalysts

Abstract

Photocatalytic decolorization of a new water soluble azo-azomethine dye, sodium 4-((4-hydroxy-3-((2-(4-(4-(2-hydroxy-5-((4-sulfonatophenyl)diazenyl)benzylide-neamino)butyl)piperazin-1-yl)ethylimino)methyl)phenyl)diazenyl)benzenesulfonate, 2,4-PIP, has been reviewed under solar light and UV irradiation. The effects of experimental parameters such as (i) initial dye concentration, (ii) the nanophotocatalyst dosage, (iii) hydrogen peroxide concentration, (iv) irradiation time, and (v) pH on photodecolorization of the dye have been investigated. The photocatalytic activity of TiO₂ and ZnO on rate and efficiency of decolorization was also investigated. The result indicated that TiO₂ was a valuable alternative nanocatalyst than ZnO for decolorization of the dye in the presence of solar light and UV irradiation at pH 5–7. Furthermore, maximum decolorization of the dye (more than 95%) was occurred in the presence of TiO₂ during 30 min under solar light. The intermediate products of photodecolorization were also identified using gas chromatography–mass spectrometry.

Keywords:

• Azo-azomethine
• Photodecolorization
• Solar light
• UV irradiation
• Nanophotocatalyst

Acknowledgment

We are grateful to the Arak University for financial support of this work [number 91/5390].