Thiol-functionalized silica nanoparticles for separation and removal of heavy metal ions from aquatic environments

Thiol-functionalized silica nanoparticles (SiO2-SH) were prepared by sol-gel method through using 3mercaptopropyltrimethoxysilane and nano sized silica. The adsorbent were characterized by FTIR, TGA and CHNS. It was found that the SiO2-SH could effectively remove the Pb2+, Ni2+, and Hg2+ ions in the solution through electrostatic and chemical interactions. The adsorption isotherm and adsorption capacity of the functional nanoparticles for different metal ions and its selectivity were investigated. Similarly, the effect of pH values on the adsorption of metal ions was studied. The strong adsorption ability of SiO2-SH can be attributed to the functional nonoparticles with rich thiol group facilitating the mass transport of metal ions to the active sites.