Synthesis and application of thiolated mesoporous silicas for sorption, preconcentration and determination of platinum

Abstract

Thiol-functionalized mesoporous silicas were synthesized by co-condensation of tetraethoxysilane (TEOS) and mercaptopropyltriethoxysilane (MPTES). All materials exhibit high values of specific surface area (456–857 m2/g), pore volume (0.5–1.3 cm3), and pore sizes (2.5–5.3 nm). These values gradually decrease with the increasing amount of MPTES. The obtained thiolated mesoporous silicas were used as sorbents of Pt(IV) species from water solution. The obtained materials exhibit an extremely good ability to remove Pt(IV) ions in the pH range 1–4. The highest adsorption capacity of platinum ions onto the thiolated mesoporous silica reached the value of 222 mg/g (1.14 mmol/g). The analytical applicability of the synthesized sorbents for Pt(IV) preconcentration was investigated and validated using the platinum reference materials. High accuracy of platinum determination was achieved which makes the obtained silicas very promising materials for the above mentioned application.