Details

Autor(en) / Beteiligte

• Manos, Manolis J.
• Petkov, Valeri G.
• Kanatzidis, Mercouri G.

Titel

H2xMnxSn3‐xS6 (x = 0.11–0.25): A Novel Reusable Sorbent for Highly Specific Mercury Capture Under Extreme pH Conditions

Ist Teil von

• Advanced functional materials, 2009-04, Vol.19 (7), p.1087-1092

Ort / Verlag

Weinheim: WILEY‐VCH Verlag

Erscheinungsjahr

2009

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• The H2xMnxSn3‐xS6 (x = 0.11–0.25) is a new solid acid with a layered hydrogen metal sulfide (LHMS). It derives from K2xMnxSn3–xS6 (x = 0.5–0.95) (KMS‐1) upon treating it with highly acidic solutions. We demonstrate that LHMS‐1 has enormous affinity for the very soft metal ions such as Hg2+ and Ag+ which occurs via a rapid ion exchange process. The tremendous affinity of LHMS‐1 for Hg2+ is reflected in very high distribution coefficient KdHg values (>106 mL g−1). The large affinity and selectivity of LHMS‐1 for Hg2+ persists in a very wide pH range (from less than zero to nine) and even in the presence of highly concentrated HCl and HNO3 acids. LHMS‐1 is significantly more selective for Hg2+ and Ag+ than for the less soft cations Pb2+ and Cd2+. The Hg2+ ions are immobilized in octahedral sites between the sulfide layers of the materials via Hg–S bonds as suggested by pair distribution function (PDF) analysis. LHMS‐1 could decrease trace concentrations of Hg2+ (e.g. <100 ppb) to well below the acceptable limits for the drinking water in less than two min. Hg‐laden LHMS‐1 shows a remarkable hydrothermal stability and resistance in 6 M HCl solutions. LHMS‐1 could be regenerated by treating Hg‐loaded samples with 12 M HCl and re‐used without loss of its initial exchange capacity. A novel layered metal‐sulfide acid H2xMnxSn3–xS6 (x = 0.11–0.25) [LHMS‐1] was isolated by acid–induced transformation of K2xMnxSn3–xS6 (x = 0.5–0.95). LHMS‐1 exhibits outstanding capability and selectivity for Hg2+ ions over a very broad pH range. The mercury ions are immobilized in octahedral sites between the sulfide layers of the materials via HgS bonds. The exceptional mercury remediation properties of LHMS‐1 persist even in the presence of highly concentrated acids.