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Title: Efficient and selective heavy metal sequestration from water by using layered sulfide K 2x Sn 4-x S 8-x (x = 0.65–1; KTS-3)

Abstract

Heavy metal ions (Cd 2+, Hg 2+, As 3+ and Pb 2+) are an important contributor to the contamination of groundwater and other water bodies in and around industrial areas. Herein, we demonstrate the rapid and efficient capacity of a layered metal sulfide material, K2xSn4-xS8-x (x = 0.65-1, KTS-3) for heavy metal ion removal from water. The effect of concentration, pH, kinetics, and competitive ions such as Na +/Ca 2+ on the heavy metal ion removal capacity of KTS-3 was systematically investigated. X-ray photoelectron spectroscopy (XPS), elemental analyses, and powder X-ray diffraction studies revealed that the heavy metal ion-exchange of KTS-3 is complete (quantitative replacement of all potassium ions) and topotactic. The heavy metal ion-exchange by using KTS-3 follows the Langmuir-Freundlich model with high exchange capacities, q(m) 205(17) mg g -1 for Cd 2+, 372(21) mg g -1 for Hg 2+ and 391(89) mg g -1 for Pb 2+. KTS-3 retains excellent heavy metal ion-exchange capacity even in very high concentration (1 M) of competing ions (Na +/Ca 2+) and also over a broad pH range (2-12). KTS-3 also exhibits very good ion-exchange capacity for precious Ag + and toxic As 3+ ions. The kinetics of heavy metal ion adsorptionmore » by KTS-3 are rapid (absorbs all ions within a few minutes). These properties and the environmentally friendly character of KTS-3 make it a promising candidate for sequestration of heavy metal ions from water.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF); University of Chicago; W.M. Keck Foundation
OSTI Identifier:
1334763
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Materials Chemistry. A; Journal Volume: 4; Journal Issue: 42
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Sarma, Debajit, Islam, Saiful M., Subrahmanyam, K. S., and Kanatzidis, Mercouri G. Efficient and selective heavy metal sequestration from water by using layered sulfide K 2x Sn 4-x S 8-x (x = 0.65–1; KTS-3). United States: N. p., 2016. Web. doi:10.1039/c6ta06404c.
Sarma, Debajit, Islam, Saiful M., Subrahmanyam, K. S., & Kanatzidis, Mercouri G. Efficient and selective heavy metal sequestration from water by using layered sulfide K 2x Sn 4-x S 8-x (x = 0.65–1; KTS-3). United States. doi:10.1039/c6ta06404c.
Sarma, Debajit, Islam, Saiful M., Subrahmanyam, K. S., and Kanatzidis, Mercouri G. Fri . "Efficient and selective heavy metal sequestration from water by using layered sulfide K 2x Sn 4-x S 8-x (x = 0.65–1; KTS-3)". United States. doi:10.1039/c6ta06404c.
@article{osti_1334763,
title = {Efficient and selective heavy metal sequestration from water by using layered sulfide K 2x Sn 4-x S 8-x (x = 0.65–1; KTS-3)},
author = {Sarma, Debajit and Islam, Saiful M. and Subrahmanyam, K. S. and Kanatzidis, Mercouri G.},
abstractNote = {Heavy metal ions (Cd2+, Hg2+, As3+ and Pb2+) are an important contributor to the contamination of groundwater and other water bodies in and around industrial areas. Herein, we demonstrate the rapid and efficient capacity of a layered metal sulfide material, K2xSn4-xS8-x (x = 0.65-1, KTS-3) for heavy metal ion removal from water. The effect of concentration, pH, kinetics, and competitive ions such as Na+/Ca2+ on the heavy metal ion removal capacity of KTS-3 was systematically investigated. X-ray photoelectron spectroscopy (XPS), elemental analyses, and powder X-ray diffraction studies revealed that the heavy metal ion-exchange of KTS-3 is complete (quantitative replacement of all potassium ions) and topotactic. The heavy metal ion-exchange by using KTS-3 follows the Langmuir-Freundlich model with high exchange capacities, q(m) 205(17) mg g-1 for Cd2+, 372(21) mg g-1 for Hg2+ and 391(89) mg g-1 for Pb2+. KTS-3 retains excellent heavy metal ion-exchange capacity even in very high concentration (1 M) of competing ions (Na+/Ca2+) and also over a broad pH range (2-12). KTS-3 also exhibits very good ion-exchange capacity for precious Ag+ and toxic As3+ ions. The kinetics of heavy metal ion adsorption by KTS-3 are rapid (absorbs all ions within a few minutes). These properties and the environmentally friendly character of KTS-3 make it a promising candidate for sequestration of heavy metal ions from water.},
doi = {10.1039/c6ta06404c},
journal = {Journal of Materials Chemistry. A},
number = 42,
volume = 4,
place = {United States},
year = {Fri Sep 16 00:00:00 EDT 2016},
month = {Fri Sep 16 00:00:00 EDT 2016}
}
  • The fission of uranium produces radionuclides, 137Cs and 90Sr, which are major constituents of spent nuclear fuel. The half-life of 137Cs and 90Sr is nearly 30 years and thus that makes them harmful to human life and the environment. The selective removal of these radionuclides in the presence of high salt concentrations from industrial nuclear waste is necessary for safe storage. We report the synthesis and crystal structure of K 2xSn 4-xS 8-x (x = 0.65–1, KTS-3) a material which exhibits excellent Cs +, Sr 2+ and UO 2 2+ ion exchange properties in varying conditions. Furthermore, the compound adoptsmore » a layered structure which consists of exchangeable potassium ions sandwiched between infinite layers of octahedral and tetrahedral tin centers. K 2xSn 4-xS 8-x (x = 0.65–1, KTS-3) crystallizes in the monoclinic space group P2 1/c with cell parameters a = 13.092(3) Å, b = 16.882(2) Å, c = 7.375(1) Å and β = 98.10(1)°. Refinement of the single crystal diffraction data revealed the presence of Sn vacancies in the tetrahedra that are long range ordered. The interlayer potassium ions of KTS-3 can be exchanged for Cs +, Sr 2+ and UO 2 2+. KTS-3 exhibits rapid and efficient ion exchange behavior in a broad pH range. The distribution coefficients (K d) for KTS-3 are high for Cs + (5.5 × 10 4), Sr 2+ (3.9 × 10 5) and UO 2 2+ (2.7 × 10 4) at neutral pH (7.4, 6.9, 5.7 ppm Cs +, Sr 2+ and UO 2 2+, respectively; V/m ~ 1000 mL g -1). KTS-3 exhibits impressive Cs +, Sr 2+ and UO 2 2+ ion exchange properties in high salt concentration and over a broad pH range, which coupled with the low cost, environmentally friendly nature and facile synthesis underscores its potential in treating nuclear waste.« less
  • Three new lanthanide metal polysulfides have been synthesized in supercritical ammonia: [Yb(NH{sub 3}){sub 8}][Cu(S{sub 4}){sub 2}]{center_dot} NH{sub 3} (I), [Yb(NH{sub 3}){sub 8}][Ag(S{sub 4}){sub 2}]{center_dot}2NH{sub 3} (II), [La(NH{sub 3}){sub 9}][Cu(S{sub 4}){sub 2}] (III). Compounds were prepared in sealed quartz tubes which were filled to one-third volume with liquid ammonia and heated at 170 {degrees}C for 3 days. Compounds I and II were obtained from the reaction of a premade ytterbium polysulfide with M and S in the ratio of 1:1:4, while [La(NH{sub 3}){sub 9}][Cu(S{sub 4}){sub 2}], III, was obtained by reacting La, Cu and S in the ratio of 1:1:8. Inmore » all these compounds, the lanthanide cation is coordinated only by ammonia, while the M{sup +} is chelated by S{sub 4}{sup 2-} to form metal tetrasulfide rings. [Yb(NH{sub 3}){sub 8}][Cu(S{sub 4}){sub 2}]{center_dot}NH{sub 3} and [Yb(NH{sub 3}){sub 8}][Ag(S{sub 4}){sub 2}]{center_dot}2NH{sub 3} contain [M(S{sub 4}){sub 2}]{sup 3-} anionic units with M{sup +} in a distorted tetrahedral coordination environment chelated by two S{sub 4}{sup 2-} groups. Compound III, [La(NH{sub 3}){sub 9}][Cu-(S{sub 4}){sub 2}], also contains anionic [Cu (S{sub 4}){sub 2}]{sup 3-} units; however, Cu{sup +} is in a trigonal planar coordination geometry due to the presence of one monodentate S{sub 4}{sup 2-}. All the compounds are unstable with respect to loss of ammonia, and decomposition yielded known ternary and binary phases.« less
  • Polyatomic main-group anions like Sn/sub 9//sup 4 -/, Te/sub 5//sup 2 -/, Se/sub 6//sup 2 -/, S/sub 6//sup 2 -/, and SnTe/sub 4//sup 4 -/ have been isolated without the use of cryptate ligands. The polychalcogenides (Bu/sub 4/N)/sub 2/M/sub x/ (where M = Te, x = 5; M = Se, x = 6; M = S, x = 6; Bu = n-C/sub 4/H/sub 9/) are obtained by the aqueous extraction of binary alkali-metal/main-group alloys in the presence of Bu/sub 4/NBr. These polychalcogenides are isomorphous and have been structurally characterized by x-ray crystallography. The nonastannide(4-) anion has been isolated both asmore » the tetrakis(tetramethylammonium) compound, ((CH/sub 3/)N)3$Sn/sub 9/, and as the HMPA (hexamethylphosphoric triamide) solvate, (K(HMPA)/sup 2/)/sub 4/Sn/sub 9/. Both compounds are somewhat thermally unstable at 25/sup 0/C. The compound K/sub 4/SnTe/sub 4/ has been isolated by the aqueous extraction of ternary K/Sn/Te alloys. 44 references, 2 figures, 1 table.« less
  • Synthetic hollandite compounds of composition Ba/sub x/M(IV)/sub 4-2x/N(III)/sub 2x/O/sub 8/ (M=Ti, Ge, Ru, Zr, Sn; N=Al, Sc, Cr, Ga, Ru, In) and Sr/sub x/M(IV)/sub 4-2x/N(III)/sub 2x/O/sub 8/ (M=Ti, Ge, Ru; N=Al, Cr, Ga) and (A, Ba)/sub x/Ti/sub y/Al/sub z/O/sub 8/ with A=Rb, Cs, Ca, Sr have been studied by electron and X-ray diffraction and high resolution electron microscopy. They have been found to be stable only within certain ranges of x, depending on the M and N ions. The lower value of x is never less than 0.56, the upper x level is about 0.73. Higher x are correlated withmore » larger radii of M and N. The variation in x gives rise to an incommensurate occupation by the A ions in the tunnels. Correlation among tunnel sequences varies widely, also depending on the nature of the M and N ions. The lower and upper x, the cell dimensions, the correlation between the tunnels and the stability in water at 300/sup 0/C of the existing hollandites are given.« less