Abstract

In this article, we report on and compare the texture, thermal properties, and adsorption capacity of aminated nanoporous activated carbon fibers (NACFs), which were prepared using the bromination followed by the amination with ethylenediamine, diethylamine, monoethanolamine, and sulfolanylethylenediamine. FTIR ATR confirmed the grafting of the amino groups. Surface morphology and microstructure of NACFs were assessed based on the results of SEM and nitrogen adsorption. Simulation of nitrogen adsorption with 2D-NLDFT models showed a highly porous structure with nanopore diameters between 0.5 and 0.8 nm and from 1.1 to 2.1 nm. The aminated NACFs with up to 0.95 mmol of amino groups per gram have moderate thermal stability. Thermal decomposition and detachment of amino groups were registered by TPD MS and TGA between 200 °C and 400 °C. Effective adsorption of 80–98% of Cd²⁺ and Cu²⁺ ions from very dilute water solutions were achieved with the aminated NACFs. The equilibrium adsorption isotherms for Cd²⁺ and Cu²⁺ were well fitted with the Langmuir and Dubinin-Radushkevich (DR) models. These results suggest sufficient energy homogeneity of the carbon surfaces and adsorption in the nanopores. As compared with the unmodified NACFs, the adsorption of Cd²⁺ and Cu²⁺ ions on the aminated surface of the NACFs is characterized by up to three times higher values of the maximum adsorption capacity and from two to five times higher values of the constants describing the adsorption equilibrium for each model.

摘要

在本文中，我们报告并比较了胺化纳米多孔活性炭纤维 (NACF) 的质地、热性能和吸附能力，这些纤维是使用溴化后与乙二胺、二乙胺、单乙醇胺和磺基乙二胺胺化制备的。FTIR ATR 证实了氨基的接枝。基于SEM和氮吸附的结果评估NACF的表面形貌和微观结构。使用 2D-NLDFT 模型对氮吸附的模拟显示出高度多孔的结构，其纳米孔径介于 0.5 和 0.8 nm 之间，以及介于 1.1 到 2.1 nm 之间。每克具有高达 0.95 mmol 氨基的胺化 NACF 具有中等热稳定性。TPD MS 和 TGA 在 200 °C 和 400 °C 之间记录了氨基的热分解和脱离。²⁺和Cu ²⁺离子来自非常稀的水溶液，是用胺化NACF 实现的。Cd ²⁺和Cu ²⁺的平衡吸附等温线与Langmuir 和Dubinin-Radushkevich (DR) 模型非常吻合。这些结果表明碳表面和纳米孔中的吸附具有足够的能量均匀性。与未改性的 NACF 相比，Cd ²⁺和 Cu ²⁺离子在 NACF 的胺化表面上的吸附的特点是最大吸附容量值高出三倍，常数值高出 2 到 5 倍描述每个模型的吸附平衡。