Two-Dimensional Molybdenum Disulfide as a Superb Adsorbent for Removing Hg 2+ from Water

作者：Feifei Jia, Qingmiao Wang, Jishan Wu, Yanmei Li, Shaoxian Song · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2017 · DOI：10.1021/acssuschemeng.7b01880 · 被引用次数：198 · 研究领域：2D Materials and Applications、MXene and MAX Phase Materials、Advanced Photocatalysis Techniques

One feature of two-dimensional (2D) molybdenum disulfide nanosheets is the huge sulfur-rich surface area, which might lead to the strong adsorption of Hg 2+ in water, because the sulfur on the surfaces could strongly bind to Hg 2+ . In this work, the adsorption of Hg 2+ on 2D molybdenum disulfide sheets in water has been studied in order to develop a novel and efficient adsorbent for removing Hg 2+ from water. The study was performed through the measurements of adsorption isotherm and kinetics, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS). The partially oxidized 2D molybdenum disulfide sheets with less than five S–Mo–S layers were prepared through the exfoliation of natural molybdenite. AFM observations illustrated a fast and multilayer Hg 2+ adsorption on the surface of 2D molybdenum disulfide. The results of adsorption tests and SEM-EDS have indicated that 2D molybdenum disulfide was a superb adsorbent. The adsorption followed the Freundlich isotherm model and fitted well with pseudo-second-order kinetics model. The excellent Hg 2+ capture property was mainly attributed to the complexation of Hg 2+ with intrinsic S and oxidation-induced O atom exposed on 2D molybdenum disulfide surfaces, as well as the electrostatic interaction between negatively charged 2D molybdenum disulfide and cation Hg 2+ .