Abstract
The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS4, NaGdSnS4, and NaTbSnS4 is reported. Rare earth metal ions like Y3+, Gd3+, and Tb3+ react with the chalcogenide clusters [SnS4](4-) in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m(2)g(-1) (NaYSnS4), 479 m(2)g(-1) (NaGdSnS4), and 354 m(2)g(-1) (NaTbSnS4). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2-50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO2 over CH4 or H-2. The notable adsorption capacity for toluene (NaYSnS4: 1108 mgg(-1); NaGdSnS4: 921 mgg(-1); and NaTbSnS4: 645 mgg(-1)) and high selectivity for gases (CO2/H-2: 172 and CO2/CH4: 50 for NaYSnS4, CO2/H-2: 155 and CO2/CH4: 37 for NaGdSnS4, and CO2/H-2: 75 and CO2/CH4: 28 for NaTbSnS4) indicate potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes.