Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (12): 3680.doi: 10.7503/cjcu20210534

• Physical Chemistry • Previous Articles     Next Articles

Experimental and DFT Studies on the Adsorption of Cd(II) Ions from Aqueous Solutions by Nanofiber Modified Thiourea Groups

LI Min1(), ZHAO Chun2, FENG Qinzhong3, FENG Jian1, MENG Xiaojing1   

  1. 1.Department of Chemical Engineering,Chongqing University of Science and Technology,Chongqing 401331,China
    2.College of Environment and Ecology,Chongqing University,Chongqing 400045,China
    3.College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2021-07-23 Online:2021-12-10 Published:2021-10-09
  • Contact: LI Min E-mail:limin1406@163.com
  • Supported by:
    the National Natural Science Foundation of China(51708075);the Natural Science Foundation of Chongqing, China(cstc2020jcyj?msxmX0789);the China Postdoctoral Science Foundation(2021T140625)

Abstract:

Cadmium is a highly toxic metal, and Cd(II) ions is a great threat to the ecological environment and human body. Herein, a new nanofiber modified thiourea groups was prepared using polyacrylonitrile (PAN) as the raw materials based on electrospinning and chemical grafting, which was used as an efficient adsorbent to remove Cd(II) ions from aqueous solutions. Several characterized techniques, including Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy(XPS) and density functional theory(DFT) theoretical calculations, were introduced to reveal the adsorption mechanism of FGTG(fiber modified by thiourea group) towards Cd(II) ions. The adsorption behavior of Cd(II) ions on the FGTG was investigated through batch and column experiments. The results show that the maximum uptake of Cd(II) ions on the FGTG was 349.46 mg/g. The adsorption equilibrium was reached within 90 min and the adsorption isotherms fitted well with the Langmuir isotherm, and the obtained kinetic data support a pseudo-second order adsorption process. The adsorption mechanism of Cd(II) ions on the FGTG is the surface coordination complexation, and it is an important way to improve the adsorption capa? city of Cd(II) ions to enhance the content of thiourea groups in the adsorbent. Moreover, obvious change on the dynamic adsorption uptake of Cd(II) ions was not been found even after six cycles. An adsorbent on Cd(II) ions with low flow resistance was fabricated in this study and the adsorption mechanism was revealed by a series of characterized techniques and DFT.

Key words: Cadmium ion, Adsorption, Chelating nanofiber, Adsorption mechanism, Density functional theory

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