Enhanced photodegradation of hazardous tartrazine by composite of nanomolecularly imprinted polymer-nanophotocatalyst with high efficiency

Abstract

In this research, a nanocomposite of molecularly imprinted polymer (MIP)-nanophotocatalyst for enhanced photodegradation of tartrazine with high efficiency and nanocomposite of non-imprinted polymer (NIP)-nanophotocatalyst were synthesized by precipitation polymerization and it was carried out in an aqueous medium to employ a green method. Acrylamide as functional monomer, N,Nʹ-methylene-bis-acrylamide as cross-linking agent, tartrazine as a template, and TiO₂ as a nanophotocatalyst were used. The synthesized nanocomposites (MIP-TiO₂ and NIP-TiO₂) were characterized by using thermal gravimetric analysis, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. The MIP nanocomposite as an effective sorbent was used to extract and photodegrade tartrazine from water media. The effects of pH, time, and concentration of tartrazine solution and kinetics of photodegradation of tartrazine were investigated. The best pH and the optimum time for tartrazine photodegradation in a 10 ml solution containing tartrazine (3 × 10⁻⁵M) and nanocomposite (1 mg) were obtained to be 2 and 5 h, respectively. The results showed that the MIP nanocomposite has improved the photodegradation of tartrazine by 100% compared to NIP nanocomposite and pure nanophotocatalyst which yielded at 63 and 56%, respectively, under the same condition.

Keywords:

• Enhanced photodegradation
• MIP nanocomposite
• Tartrazine
• NIP nanocomposite
• Green synthesis
• TiO₂ nanophotocatalyst

Acknowledgments

The authors wish to thank the Iran National Science Foundation, Iran Nano Technology Initiative Council, Tehran University of Medical Sciences and Amirkabir University of Technology for the financial and instrumental support of this research.