Fast and Effective Decontamination of Aqueous Mercury by a Highly Stable Zeolitic-like Chalcogenide

Abstract

Highly efficient and effective removal of mercury from water, especially at very low ionic concentration, remains a grand challenge for ecosystem protection and human health. Herein, we present the synthesis, crystal structure, and mercury uptake performance of a new heterometallic chalcogenidometalate, namely, [TAEAH]-[TAEAH 2 ] 0.6 Ga 2.2 Sn 1.8 S 8 •H 2 O (GaSnS-1; TAEA = Tris(2-aminoethyl)amine). GaSnS-1 features a three-dimensional (3D) zeolite-typed (RWY) framework structure of [Ga 2.2 Sn 1.8 S 8 ] n 2.2n− that is constructed by corner-sharing of supertetrahedral [Ga 2.2 Sn 1.8 S 10 ] 6.2− T2 clusters. The equilibrium model study indicated that the maximum Hg 2+ saturation capacity of GaSnS-1 was 213.9 mg/g. GaSnS-1 possessed extremely rapid adsorption kinetics following the pseudo-second-order model with a k 2 of 5.65 × 10 2 g• mg −1 •min −1 . Particularly, GaSnS-1 exhibited excellent selectivity for Hg 2+ ions with a high distribution coefficient K d value of 1.62 × 10 7 mL/g and high removal efficiency of close to 100%. The superior Hg 2+ ion adsorption performance was also impressive despite the presence of excessive competing cations and the acidic/basic conditions. Furthermore, a simple chromatographic column loaded with GaSnS-1 microcrystals is capable of rapidly and effectively capturing Hg 2+ ions far below the upper limit (2 ppb, USA-EPA) of drinking water. These advantages of GaSnS-1 make it a promising candidate for the fast and efficient remediation of Hg 2+ -contaminated water sources.

Reusable Polyacrylonitrile‐Sulfur Extractor of Heavy Metal Ions from Wastewater

“…The uptake capacity of PAN‐S was better than that of natural carbon, biomass, and synthetic clay adsorbents, though less than that of thiol (‐SH) containing COF/MOF, and individual metal sulfide materials. [ 28,39,53,54 ] For example, MoS 2 and ZnS nanoparticles have superior reported saturated adsorption capacities of 340 and 2000 mg g −1 . [ 55,56 ] However, thiol (‐SH) containing COF or MOF suffer from structural vulnerabilities, and have a narrow solution pH range for adsorption.…”

Fast and Selective Removal of Aqueous Uranium by a K+-Activated Robust Zeolitic Sulfide with Wide pH Resistance

“…GaSnS-1 exhibits a 3D zeolite-like anionic framework characteristic of a [Ga 2.2 Sn 1.8 S 10 ] 6.2− T2 cluster as the secondary building unit (Figures S1 and S2). 14 It contains large supersodalite cages filled by bulky and sluggish TAEA cations, as well as guest molecules. Figure 1 shows the schematics of the stepwise ionexchange strategy to prepare a K + -activated porous sulfide and its application in uranium capture.…”

“…Herein, we rationally design a new and stable porous zeolitic-typed sulfide with an exchangeable K + ion (denoted as K@GaSnS-1) by activating GaSnS-1 ([TAEAH]­[TAEAH 2 ] 0.6 Ga 2.2 Sn 1.8 S 8 ·H 2 O, TAEA = tris­(2-aminoethyl)­amine), just reported by us . The suitability of a 3D microporous sulfide for [UO 2 ] 2+ ion capture is demonstrated first.…”

“…13 Herein, we rationally design a new and stable porous zeolitic-typed sulfide with an exchangeable K + ion (denoted as K@GaSnS-1) by activating GaSnS-1 ([TAEAH]-[TAEAH 2 ] 0.6 Ga 2.2 Sn 1.8 S 8 •H 2 O, TAEA = tris(2-aminoethyl)amine), just reported by us. 14 The suitability of a 3D microporous sulfide for [UO 2 ] 2+ ion capture is demonstrated first. Detailed studies indicate that K@GaSnS-1 exhibits highly enhanced uranium uptake kinetics (<15 min) and sorption capacity (147.6 mg/g) in comparison to the pristine compound GaSnS-1.…”

“…GaSnS-1 was solvothermally synthesized by using Ga(NO 3 ) 3 •9H 2 O, Sn, S, and TAEA at 190 °C as we just reported. 14 The title compound, namely K@GaSnS-1, was obtained via a stepwise ion-exchange strategy according to the ref 13. First, 500 mg of pristine GaSnS-1 was immersed in 100 mL of CsCl aqueous solution (1 M) at 85 °C for 2 days, during which period the CsCl solution was refreshed daily.…”