Facile sol–gel synthesis of thiol-functionalized materials from TEOS-MPTMS-PMHS system

Thiol-functionalized sol–gel materials with porous structures were successfully prepared via co-condensation of tetraethoxysilane, (3-mercaptopropyl)-trimethoxysilane, polymeric polymethylhydrosiloxane in the absence of traditional structure-directing agents under proposed basic conditions. The dependence of textural characteristics on the preparation parameters were investigated employing various techniques as such N₂ adsorption/desorption isotherms, SEM, TG-DTG, FT-IR and solid state ²⁹Si MAS NMR measurements. It was shown by these characterizations that thiol-functional groups have been successfully introduced into the porous network and the loadings could be tuned by adjusting the content of corresponding precursor in the gel system. Besides, the as-prepared samples exhibited high surface areas, large pore volume, tunable pore diameters and favorable thermal stability. Adsorption experiments indicated that thiol-incorporated materials have selective adsorption ability toward heavy metal ions from aqueous solutions, and a high capacity in adsorbing heavy metal ion of Pb²⁺ (up to 99.4%) was observed under optimized experimental conditions.