Hg2+ Trapping by Thiol – Functionalised Mesoporous Silica Molecular Sieves

Abstract

The covalent grafting of 3-mercaptopropylsilyl groups to the framework pore walls of mesoporous silica molecular sieves represents a promising new approach for trapping of Hg2+ and other heavy metals from dilute solution. Two framework structures were examined, namely, a calcined hexagonal silica prepared by electrostatic supramolecular assembly, and an uncalcined wormhole -like silica obtained through neutral surfactant assembly. Owing to the presence of a higher concentration of surface hydroxyl groups, the wormhole silica was far more effective for thiol fuctionalisation and heavy metal ion trapping.