Tian Hua, He Junhui, Hu Minghua
Functional Nanomaterials Laboratory, Center for Micro/Nanomaterials and Technology, and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Functional Nanomaterials Laboratory, Center for Micro/Nanomaterials and Technology, and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
J Colloid Interface Sci. 2019 Sep 1;551:251-260. doi: 10.1016/j.jcis.2019.05.027. Epub 2019 May 8.
Although the mercury pollution is declining in the Western and European parts of the world, it is still a widespread environmental concern because of its notorious toxic effects on aquatic ecosystems and human health. Selective and rapid enrichment is essential for timely monitoring and efficient removal of trace mercury contaminants, but has so far been a big challenge. In the current work, we report a superparamagnetic molybdenum disulfide (FeO@MoS) with an expanded interlayer spacing (1.0 nm) and high magnetic susceptibility for highly selective and rapid uptake of Hg ions. Upon treatment by FeO@MoS, over 99% of 15 ppm Hg can be removed in 2 min from aqueous solutions, with an initial adsorption rate as high as 52.62 g mg min. FeO@MoS also demonstrate capability to efficiently enrich Hg from samples with ppb levels of Hg, resulting in an ultralow residual Hg concentration (60 ppt), which is far below the acceptable limit for drinking water (2 ppb). FeO@MoS also shows high selectivity for Hgversus other eight representative metal ions. Furthermore, the selectivity for heavy metal ions can be optionally tailored by simply controlling the contact time during the uptake. This new finding is in contrast to the previously reported selectivity enhancement strategies by searching for new materials and chemical modification of adsorbents, and would enable additional improvement of selectivity by kinetic process engineering.
尽管世界的西方和欧洲地区汞污染正在下降，但由于其对水生生态系统和人类健康具有臭名昭著的毒性影响，它仍然是一个普遍存在的环境问题。选择性和快速富集对于及时监测和有效去除痕量汞污染物至关重要，但迄今为止一直是一个巨大的挑战。在当前的工作中，我们报道了一种具有扩大的层间距（1.0纳米）和高磁化率的超顺磁性二硫化钼（FeO@MoS），用于高选择性和快速摄取汞离子。用FeO@MoS处理后，在2分钟内可以从水溶液中去除超过99%的15 ppm汞，初始吸附速率高达52.62 g mg min。FeO@MoS还表现出从汞含量为ppb级的样品中有效富集汞的能力，导致超低的残余汞浓度（60 ppt），这远远低于饮用水的可接受限值（2 ppb）。FeO@MoS对汞相对于其他八种代表性金属离子也表现出高选择性。此外，通过简单地控制摄取过程中的接触时间，可以选择性地调整对重金属离子的选择性。这一新发现与先前报道的通过寻找新材料和对吸附剂进行化学改性来提高选择性的策略形成对比，并且将通过动力学过程工程实现选择性的进一步提高。
