title: Ion-Exchangeable Molybdenum Sulfide Porous Chalcogel: Gas Adsorption and Capture of Iodine and Mercury.
abstract: We report the synthesis of ion-exchangeable molybdenum sulfide chalcogel through an oxidative coupling process, using (NH4)2MoS4 and iodine. After supercritical drying, the MoS(x) amorphous aerogel shows a large surface area up to 370 m(2)/g with a broad range of pore sizes. X-ray photoelectron spectroscopic and pair distribution function analyses reveal that Mo(6+) species undergo reduction during network assembly to produce Mo(4+)-containing species where the chalcogel network consists of [Mo3S13] building blocks comprising triangular Mo metal clusters and S2(2-) units. The optical band gap of the brown-black chalcogel is ∼1.36 eV. The ammonium sites present in the molybdenum sulfide chalcogel network are ion-exchangeable with K(+) and Cs(+) ions. The molybdenum sulfide aerogel exhibits high adsorption selectivities for CO2 and C2H6 over H2 and CH4. The aerogel also possesses high affinity for iodine and mercury.
authors.forename: Kota S
authors.initials: KS
authors.lastname: Subrahmanyam
authors.forename: Christos D
authors.initials: CD
authors.lastname: Malliakas
authors.forename: Debajit
authors.initials: D
authors.lastname: Sarma
authors.affiliation: Department of Materials Science and Technology, University of Crete , Heraklion 71003, Crete, Greece.
authors.forename: Gerasimos S
authors.initials: GS
authors.lastname: Armatas
authors.forename: Jinsong
authors.initials: J
authors.lastname: Wu
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis