文摘
We report detailed studies showing that the novel layered polysulfide compounds Sx-LDH (Sx2鈥?/sup>, polysulfides, x = 2, 4, 5; LDH, Mg鈥揂l layered double hydroxides) can capture efficiently large quantities of mercury (Hg0) vapor. During the adsorption process, the interlayer polysulfides [Sx]2鈥?/sup> react with Hg0 through their S鈥揝 bond to produce HgS. The structure of Sx-LDH before and after Hg-adsorption was characterized with X-ray diffraction, vibration spectroscopy, and scanning electron microscopy. The presence of adsorbed Hg was verified by weight gain, inductively coupled plasma atomic emission spectroscopy and X-ray photoelectron spectroscopy. Despite their relatively low surface areas, the S2-LDH, S4-LDH, and S5-LDH samples show excellent Hg capture capacities of 4.9 脳 105, 7.4 脳 105, and 1.0 脳 106 渭g/g, respectively, corresponding to 50鈥?00% adsorption rates by weight, highlighting the potential of these materials in natural gas purification. The Hg-capture efficiency and mechanism in Sx-LDH are supported by control experiments with K2S4, S8, LDH-NO3-CoS4, and MgAl-NO3-LDH.