Fabrication of core@shell structural Fe-Fe2O3@PHCP nanochains with high saturation magnetization and abundant amino groups for hexavalent chromium adsorption and reduction

Zhiwei Wang; Yahuan Wang; Shuai Cao; Shaohua Liu; Zhimin Chen; Jiafu Chen; Yong Chen; Jianwei Fu

doi:10.1016/j.jhazmat.2019.121483

Fabrication of core@shell structural Fe-Fe₂O₃@PHCP nanochains with high saturation magnetization and abundant amino groups for hexavalent chromium adsorption and reduction

J Hazard Mater. 2020 Feb 15:384:121483. doi: 10.1016/j.jhazmat.2019.121483. Epub 2019 Oct 16.

Authors

Zhiwei Wang¹, Yahuan Wang¹, Shuai Cao¹, Shaohua Liu², Zhimin Chen¹, Jiafu Chen¹, Yong Chen¹, Jianwei Fu³

Affiliations

¹ School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450052, PR China.
² State Key Laboratory of Precision Spectroscopy & School of Physics and Materials Science, East China Normal University, Shanghai, 200241, PR China.
³ School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450052, PR China. Electronic address: jwfu@zzu.edu.cn.

PMID: 31648891
DOI: 10.1016/j.jhazmat.2019.121483

Abstract

The rational design of novel adsorption materials is imperative to remove toxic metal species from the polluted water. Herein, a core@shell structural Fe-Fe₂O₃@poly (hexachlorocyclotriphosphazene-co-polyethylenimine) (Fe-Fe₂O₃@PHCP) magnetic nanochain with high saturation magnetization was fabricated and used for effective adsorption and reduction of hexavalent chromium. The morphology and microstructure of Fe-Fe₂O₃@PHCP were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The effects of concentration, pH, contact time, temperature and coexisting ions on Cr (VI) removal were studied. Four kinetic models (pseudo-first-order, pseudo-second-order, Bangham and intraparticle diffusion models) and two isotherm models (Freundlich and Langmuir) were used to fit experimental data. Results show the adsorption capacity of Fe-Fe₂O₃@PHCP for Cr (VI) is up to 229.0 mg g^-1. The excellent performance was ascribed to the favorable reduction of Cr (VI) to Cr (III), followed by the chelation of Cr (III) with imino groups. Meanwhile, the residual Cr (VI) were adsorbed on protonated amino and imino groups. The adsorption process is exothermic and spontaneous and nicely follows pseudo-second-order kinetics, intraparticle diffusion model and Langmuir isotherm model. These results indicated that easily separable Fe-Fe₂O₃@PHCP magnetic nanochains could be a promising adsorbent to remediate chromate wastewater.

Keywords: Adsorbent; Hexavalent chromium; Magnetic separation; Nanochains; Polymer.

Publication types

Research Support, Non-U.S. Gov't