Immobilization of gaseous elemental mercury using SnS2-Wrapped magnetic Fe3O4 microspheres.

A SnS 2 @Fe 3 O 4 composite has been easily synthesized via a KSCN fused salt approach and adopted for capturing elemental mercury at low temperature. Calcination temperature significantly impacts the mercury capture performance of SnS 2 -T. The optimal synthesis temperature for SnS 2 -T is 250 °C. Pristine SnS 2 -250 obtained at 250 °C exhibits a moderate Hg⁰ adsorption capability with mercury removing efficiency less than 65% within 80–120 °C. Fe 3 O 4 incorporation can notably improve the mercury capture ability of SnS 2 -250 probably due to the cooperative effect between SnS 2 nanoflakes and magnetic Fe 3 O 4 microspheres. SnS 2 -250@Fe 3 O 4 holds a good magnetism (saturation magnetization: 23 emu/g), which performs optimally at 100 °C with Hg⁰ capture efficiency of 95.2%. Sn⁴⁺, S²⁻, Fe³⁺ ions and chemisorbed oxygen species are principal active sites for Hg⁰ capture over SnS 2 -250@Fe 3 O 4 , which convert adsorbed Hg⁰ into HgO, HgS, and HgSO 4. • A SnS 2 @Fe 3 O 4 composite has been facilely obtained via a KSCN molten salt method. • Calcination temperature can notably influence the Hg⁰ capture performance of SnS 2. • SnS 2 nanoflakes and Fe 3 O 4 microspheres may show a synergy toward Hg⁰ capture. • Fe 3 O 4 addition can evidently enhance the mercury capture ability of tin disulfide. [ABSTRACT FROM AUTHOR]