The trimethylsilylation route to prepare modified silica with mercapto groups to remove arsenic from water sources

Abstract

The trimethylsilylation reaction (TMS) has been used in several applications as the preparation of oligosiloxanes from natural silicates. Depending on the reaction conditions, it is possible to obtain silica with interesting textural properties. Another less explored possibility is the synthesis of modified silica with different organic groups by a quite simple route. In the present study, the TMS reaction was used to obtain modified silica with mercapto groups. The adsorbent was characterized by FT-IR, solid-state NMR (²⁹Si and ¹³C), thermal analysis (DTG/DTA) and nitrogen sorption and was used to remove arsenic form standard aqueous solutions (1 ppm) in a batch system. The highest arsenic adsorption capacity (68%) is favored at 20 °C, similar to values obtained in other reports.