Cite this article as:

Yuhui Liu, Meng Tang, Shuang Zhang, Yuling Lin, Yingcai Wang, Youqun Wang, Ying Dai, Xiaohong Cao, Zhibin Zhang, and Yunhai Liu, U(VI) adsorption behavior onto polypyrrole coated 3R-MoS2 nanosheets prepared with the molten salt electrolysis method, Int. J. Miner. Metall. Mater., 29(2022), No. 3, pp.479-489. https://dx.doi.org/10.1007/s12613-020-2154-5
Yuhui Liu, Meng Tang, Shuang Zhang, Yuling Lin, Yingcai Wang, Youqun Wang, Ying Dai, Xiaohong Cao, Zhibin Zhang, and Yunhai Liu, U(VI) adsorption behavior onto polypyrrole coated 3R-MoS2 nanosheets prepared with the molten salt electrolysis method, Int. J. Miner. Metall. Mater., 29(2022), No. 3, pp.479-489. https://dx.doi.org/10.1007/s12613-020-2154-5
引用本文 PDF XML SpringerLink

熔盐电解法制备PPy/3R-MoS2纳米片及对U(VI)吸附效果的研究

摘要: 为提高水溶液中铀的分离能力,本文采用熔盐电解法制备3R-MoS2纳米片,并用聚吡咯(PPy)对其进行改性,采用水热法合成了复合纳米吸附剂(PPy/3R-MoS2)。在700 K温度下,以Mo丝为阴极,C棒为阳极,调节恒电流电位仪电流大小为2 A,对KCl–NaCl–Na2MoO4–KSCN熔盐体系进行恒电流电解1 h。待电解产物冷却至室温后,用去离子水洗涤过滤,在60℃下真空干燥2 h,得到3R-MoS2纳米片。将制备的3R-MoS2纳米片(1.0 g)分散在50 mL含PPy(2.34 mL)的去离子水中,加入10 mL(1 mol/L) FeCl3溶液,在10℃下放置24 h。将反应后的样品在5000 r/min下离心20 min,用无水乙醇和去离子水分散两次后,在70°C下真空干燥2 h,得到PPy/3R-MoS2纳米片。通过批次吸附实验,探究了制备的纳米片在不同pH、反应时间、U(VI)初始浓度和温度条件下对U(VI)的吸附效果,并利用SEM、HRTEM、XRD、FTIR和XPS对其进行表征。在不同实验条件下,与3R-MoS2和聚吡咯(PPy)相比,复合纳米吸附剂(PPy/3R-MoS2)对U(VI)的吸附能力增强。当U(VI)初始浓度为80–100 mg/L时, PPy、3R-MoS2和PPy/3R-MoS2的吸附均达到平衡,最大吸附量分别为30.9、58.7和200.4 mg/g。XPS和FTIR分析阐明了其吸附机理:1) 带负电的PPy/3R-MoS2纳米片通过静电吸引捕获UO22+);2) 裸露的C,N,Mo,S原子通过配位作用与U(VI)络合;3) 络合物中的Mo将吸附的U(VI)部分还原为U(IV),再生了吸附位点,从而连续吸附U(VI)。具有高吸附容量和化学稳定性的PPy/3R-MoS2复合材料的设计为放射性核素的去除提供了新的方向。

 

U(VI) adsorption behavior onto polypyrrole coated 3R-MoS2 nanosheets prepared with the molten salt electrolysis method

Abstract: To improve the separation capacity of uranium in aqueous solutions, 3R-MoS2 nanosheets were prepared with molten salt electrolysis and further modified with polypyrrole (PPy) to synthesize a hybrid nanoadsorbent (PPy/3R-MoS2). The preparation conditions of PPy/3R-MoS2 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-MoS2 exhibited enhanced adsorption capacity toward U(VI) compared to pure 3R-MoS2 and PPy; the maximum adsorption was 200.4 mg/g. The adsorption mechanism was elucidated with XPS and FTIR: (1) negatively charged PPy/3R-MoS2 nanosheets attracted \rmUO_2^2 + 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-MoS2 composite with a high adsorption capacity and chemical stability provides a new direction for the removal of radionuclide.

 

/

返回文章
返回