Oxidative degradation of Rhodamine B in aqueous solution using Fe/PANI nanoparticles in the presence of AQS serving as an electron shuttle

Abstract

In this study, core-shell Fe⁰@polyaniline (PANI) nanoparticles were synthesized to remove Rhodamine B (RhB) in aqueous solution. The Fe⁰/PANI composites were characterized by X-ray diffraction, Fourier transform infrared spectra, and transmission electron microscopy. The performances of Fe⁰/PANI on the activation of molecular oxygen for the removal of RhB were investigated, and the effects of operating parameters, such as Fe⁰/PANI dosage, RhB initial concentration, and pH value on RhB removal were also discussed. The results indicated that the Fe⁰@PANI/O₂ process exhibited significantly higher reactivity than did the Fe⁰/O₂ process for the degradation of RhB. The oxidative degradation of RhB was further promoted by the presence of anthraquinone-2-sulfonic acid sodium salt working as an electron shuttle. In addition, the reaction mechanism was discussed by measuring the concentrations of Fe(II), and total Fe formed in the system and examining scavenging effect by tert-butyl alcohol and copper chloride. The redox mediating function of PANI was also revealed by the UV–vis spectra. The stability of Fe⁰@PANI showed that it is a potential nanomaterial for the environmental remediation.

Keywords:

• Core-shell Fe⁰@PANI nanoparticles
• Dioxygen activation
• Rhodamine B
• Electron shuttle
• Anthraquinone-2-sulfonic acid sodium salt
• Degradation

Acknowledgments

This work was supported by the Shandong Provincial Natural Science Foundation, China (Grant No. ZR2013EEM004) and the Shandong Provincial Science and Technology Development Program, China (Grant No. 2014GSF117008).