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

In this study, core-shell Fe-0@polyaniline (PANI) nanoparticles were synthesized to remove Rhodamine B (RhB) in aqueous solution. The Fe-0/PANI composites were characterized by X-ray diffraction, Fourier transform infraredspectra, and transmission electron microscopy. The performances of Fe-0/PANI on the activation of molecular oxygen for the removal of RhB were investigated, and the effects of operating parameters, such as Fe-0/PANI dosage, RhB initial concentration, and pH value on RhB removal were also discussed. The results indicated that the Fe-0@PANI/O-2 process exhibited significantly higher reactivity than did the Fe-0/O-2 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 Fe-0@PANI showed that it is a potential nanomaterial for the environmental remediation.