Abstract:
To improve the separation capacity of uranium in aqueous solutions, 3R-MoS
2 nanosheets were prepared with molten salt electrolysis and further modified with polypyrrole (PPy) to synthesize a hybrid nanoadsorbent (PPy/3R-MoS
2). The preparation conditions of PPy/3R-MoS
2 were investigated and the obtained nanosheets were characterized with scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS). The results showed that PPy/3R-MoS
2 exhibited enhanced adsorption capacity toward U(VI) compared to pure 3R-MoS
2 and PPy; the maximum adsorption was 200.4 mg/g. The adsorption mechanism was elucidated with XPS and FTIR: (1) negatively charged PPy/3R-MoS
2 nanosheets attracted
\rmUO_2^2 + ![](IJM-06-2020-0630_M1.jpg)
by an electrostatic interaction; (2) exposed C, N, Mo, and S atoms complexed with U(VI) through coordination; (3) Mo in the complex partly reduced the adsorbed U(VI) to U(IV), which further regenerated the adsorption point and continuously adsorbed U(VI). The design of the PPy/3R-MoS
2 composite with a high adsorption capacity and chemical stability provides a new direction for the removal of radionuclide.