Department of Chemistry, Oklahoma State University, Stillwater, OK 74078, USA.
Nanotechnology. 2012 Jul 27;23(29):294014. doi: 10.1088/0957-4484/23/29/294014. Epub 2012 Jun 28.
Nanocrystalline (1.7 ± 0.3 nm) zinc sulfide with a specific surface area up to 360 m(2) g(-1) was prepared from the thermal decomposition of a single-source precursor, zinc ethylxanthate. Zinc ethylxanthate decomposes to cubic zinc sulfide upon exposure to temperatures greater than or equal to 125 °C. The resulting zinc sulfide was tested as a water impurity extractant. The target impurities used in this study were As(5+), As(3+), and Pb(2+). The reaction of the nanocrystalline ZnS with Pb(2+) proceeds as a replacement reaction where solid PbS is formed and Zn(2+) is released into the aqueous system. Removal of lead to a level of less than two parts per billion is achievable. The results of a detailed kinetics experiment between the ZnS and Pb(2+) are included in this study. Unlike the instance of lead, both As(5+) and As(3+) adsorb on the surface of the ZnS extractant as opposed to an ion-exchange process. An uptake capacity of > 25 mg g(-1) for the removal of As(5+) is possible. The uptake of As(3+) appears to proceed by a slower process than that of the As(5+) with a capacity of nearly 20 mg g(-1). The nanocrystalline zinc sulfide was extremely successful for the removal of arsenic and lead from simulated oil sand tailing pond water.
纳米晶（1.7 ± 0.3nm）的硫化锌比表面积高达 360m2/g，由单源前驱体乙硫代黄原酸锌热分解制备。乙硫代黄原酸锌在温度高于或等于 125°C 时分解为立方硫化锌。所得的硫化锌被测试为水杂质萃取剂。本研究中使用的目标杂质为 As(5+)、As(3+)和 Pb(2+)。纳米晶 ZnS 与 Pb(2+)的反应是一种取代反应，生成固体 PbS，同时将 Zn(2+)释放到水溶液中。可以将铅去除到低于 20 亿分之一的水平。本研究包括 ZnS 和 Pb(2+)之间详细动力学实验的结果。与铅不同，As(5+)和 As(3+)作为吸附物而非离子交换过程吸附在 ZnS 萃取剂的表面上。对于去除 As(5+)，吸附容量>25mg/g 是可能的。As(3+)的吸附似乎比 As(5+)的吸附过程慢，吸附容量接近 20mg/g。纳米晶硫化锌在去除模拟油砂尾矿水中的砷和铅方面非常成功。
