title: Enhanced adsorption of mercury ions on thiol derivatized single wall carbon nanotubes.
abstract: Thiol-derivatized single walled carbon nanotube (SWCNT-SH) powders were synthesized by reacting acid-cut SWCNTs with cysteamine hydrochloride using carbodiimide coupling. Infrared (IR) spectroscopy, Raman spectroscopy and thermogravimetric analysis confirmed the successful functionalization of the SWCNTs. SWCNT-SH powders exhibited a threefold higher adsorption capacity for Hg(II) ions compared to pristine SWCNTs, and a fourfold higher adsorption capacity compared to activated carbon. The influence of adsorption time, pH, initial metal concentration and adsorbent dose on Hg(II) ion removal was investigated. The maximum adsorption capacity of the SWCNT-SH powders was estimated by using equilibrium isotherms, such as Freundlich and Langmuir, and the maximum adsorption capacity of the SWCNT-SH powder was found to be 131 mg/g. A first-order rate model was employed to describe the kinetic adsorption process of Hg(II) ions onto the SWCNT-SH powders. Desorption studies revealed that Hg(II) ions could be easily removed from the SWCNT-SH powders by altering the pH. Further, the adsorption efficiency of recovered SWCNT-SH powders was retained up to 91%, even after 5 adsorption/desorption cycles.
authors.affiliation: Flinders Centre for NanoScale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Adelaide, SA 5001, Australia.
authors.forename: Narasimha Murthy
authors.initials: NM
authors.lastname: Bandaru
authors.forename: Nekane
authors.initials: N
authors.lastname: Reta
authors.forename: Habibullah
authors.initials: H
authors.lastname: Dalal
authors.forename: Amanda V
authors.initials: AV
authors.lastname: Ellis
authors.forename: Joseph
authors.initials: J
authors.lastname: Shapter
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Voelcker
mesh_terms: D000327:Adsorption; D008628:Mercury / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D037742:Nanotubes, Carbon; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Adsorption; Desorption; Mercury; Nanomaterials; Single walled carbon nanotube; Thiol