Highly Efficient Iodine Capture by Layered Double Hydroxides Intercalated with Polysulfides

Journal Article · Tue Dec 23 00:00:00 EST 2014 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm5036997· OSTI ID:1392312

Ma, Shulan; Islam, Saiful M.; Shim, Yurina; Gu, Qingyang; Wang, Pengli; Li, Hao; Sun, Genban; Yang, Xiaojing; Kanatzidis, Mercouri G.

We demonstrate strong iodine (I-2) vapor adsorption using Mg/Al layered double hydroxide (MgAl-LDH) nanocomposites intercalated with polysulfide (S-x(2-)) groups (S-x-LDH, x = 2, 4, 6). The as-prepared LDH/polysulfide hybrid materials display highly efficient iodine capture resulting from the reducing property of the intercalated polysulfides. During adsorption, the I-2 molecules are reduced to I-3(-) anions by the intercalated [S-x](2-) groups that simultaneously are oxidized to form S8. In addition to the chemical adsorption, additional molecular I-2 is physically captured by the LDH composites. As a result of these parallel processes, and despite their very low BET surface areas, the iodine capture capacities of S-2-LDH, S-4-LDH, and S-6-LDH are similar to 1.32, 1.52, and 1.43 g/g, respectively, with a maximum adsorption of 152% (wt %). Thermogravimetric and differential thermal analysis (TG-DTA), energy dispersive X-ray spectroscopy (EDS), and temperature-variable powder X-ray diffraction (XRD) measurements show the resulting I-3(-) ions that intercalated into the LDH gallery have high thermal stability (>= 350 degrees C). The excellent iodine adsorption performance combined with the facile preparation points to the S-x-LDH systems as potential superior materials for adsorption of radioactive iodine, a waste product of the nuclear power industry.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1392312
• Journal Information: Chemistry of Materials, Vol. 26, Issue 24; ISSN 0897-4756
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English