Polysulfide Chalcogels with Ion-Exchange Properties and Highly Efficient Mercury Vapor Sorption

We report the synthesis of metal–chalcogenide aerogels from Pt2+ and polysulfide clusters ([Sx]2–, x = 3–6). The cross-linking reaction of these ionic building blocks in formamide solution results in spontaneous gelation and eventually forms a monolithic dark brown gel. The wet gel is transformed into a highly porous aerogel by solvent exchanging and subsequent supercritical drying with CO2. The resulting platinum polysulfide aerogels possess a highly porous and amorphous structure with an intact polysulfide backbone. These chalcogels feature an anionic network that is charged balanced with potassium cations, and hosts highly accessible S–S bonding sites, which allows for reversible cation exchange and mercury vapor capture that is superior to any known material.