High-Surface-Area Antimony Sulfide Chalcogels

Abstract

Chalcogels are a new class of aerogel materials with diverse properties relevant to catalysis, ion-exchange, and gas adsorption. We report the synthesis of high-surface-area antimony sulfide chalcogels through the sol–gel process followed by supercritical drying. Four different synthetic routes were employed: (1) hydrolysis of sodium thioantimonite (Na3SbS3); (2) ligand metathesis between Sb3+ metal linker and SbS33– anion; (3) reaction of Sb2S3 with Na2S·9H2O; and (4) reaction of Sb2S3 with KOH. All these reactions enable the formation of antimony sulfide gels. The aerogels derived after supercritical drying exhibit high porosity with Brunauer−Emmett−Teller (BET) surface areas up to 300 m2 g–1. The oxidation state of antimony in these chalcogels has been assigned by X-ray photoelectron spectroscopy (XPS) to be +3. Pair distribution function analysis suggests that the local environment around the Sb atoms is very similar to that of crystalline Sb2S3. All the antimony sulfide chalcogels possess the band gap of ∼1.75 eV, and they are thermally stable even up to 600 °C.