One-pot synthesis of mesoporous chitosan-silica composite from sodium silicate for application in Rhenium(VII) adsorption

In this work, sodium silicate (SS) is used as silica precursor for the sol-gel reaction to prepare mesoporous chitosan-silica composite by a facile one-pot method. By using sodium silicate to replace the silane coupling agents that have been used for the modification of mesoporous materials in the traditional methods, we can not only simplify the preparation process, but also overcome the significant cost problem. The prepared chitosan-silica composite with mesoporous structure and narrow pore size distribution, namely SS5/5.5-15-CTS2@95, exhibits highly efficient adsorption capacity (up to 206.31 mg g(-1)) for Re(VII) ions under pH 3.0. Significantly, our study on the adsorption-elution-regeneration recyclability indicates that this mesoporous chitosan-silica composite material possesses good stability and reusability for adsorption-related fields including the recovery of rhenium.