Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX, 77843, United States.
Department of Physics, Southern Illinois University Carbondale, IL, 62901, Carbondale, United States.
Sci Rep. 2020 Jun 19;10(1):10013. doi: 10.1038/s41598-020-66871-4.
Removal of harmful chemicals from water is paramount to environmental cleanliness and safety. As such, need for materials that will serve this purpose is in the forefront of environmental research that pertains to water purification. Here we show that bundles of single walled carbon nanotubes (SWNTs), synthesized by direct thermal decomposition of ferrocene (Fe(CH)), can remove emerging contaminants like benzoic acid from water with high efficiencies. Experimental adsorption isotherm studies indicate that the sorption capacity of benzoic acid on these carbon nanotubes (CNTs) can be as high as 375 mg/g, which is significantly higher (in some cases an order of magnitude) than those reported previously for other adsorbents of benzoic acid such as activated carbon cloth, modified bentonite and commercially available graphitized multiwall carbon nanotubes (MWNTs). Our Molecular Dynamics (MD) simulation studies of experimental scenarios provided major insights related to this process of adsorption. The MD simulations indicate that, high binding energy sites present in SWNT bundles are majorly responsible for their enhanced adsorptive behavior compared to isolated MWNTs. These findings indicate that SWNT materials can be developed as scalable materials for efficient removal of environmental contaminants as well as for other sorption-based applications.
从水中去除有害化学物质对于环境清洁和安全至关重要。因此，对于能够实现这一目的的材料的需求，成为与水净化相关的环境研究的前沿。在这里，我们展示了由直接热分解二茂铁（Fe(CH)）合成的单壁碳纳米管（SWNTs）束，可以高效地去除水中的新兴污染物，如苯甲酸。实验吸附等温线研究表明，这些碳纳米管（CNTs）对苯甲酸的吸附容量高达 375mg/g，这明显高于（在某些情况下，高一个数量级）先前报道的其他苯甲酸吸附剂，如活性炭布、改性膨润土和市售石墨化多壁碳纳米管（MWNTs）。我们对实验情景的分子动力学（MD）模拟研究提供了与这一吸附过程相关的主要见解。MD 模拟表明，SWNT 束中存在的高结合能位点是其与孤立的 MWNTs 相比具有增强吸附性能的主要原因。这些发现表明，SWNT 材料可以开发为高效去除环境污染物以及其他基于吸附的应用的可扩展材料。
