Amino-functionalized multi-walled carbon nanotubes for removal of cesium from aqueous solution

Amino-functionalized multi-walled carbon nanotubes (MWCNTs) were synthesized by a simple, cost-effective method using 3-aminopropyltriethoxysilane and were evaluated for cesium ion removal in aqueous solution. Experimental results showed that the maximum cesium adsorption capacity of amino-functionalized MWCNTs was 136.3 mg g^-1, reaching 95% of the ultimate adsorption capacity within 30 min. The adsorption capacity of amino-functionalized MWCNTs was not significantly affected by the presence of competing ions. The Langmuir isotherm fitted the experimental data well and a thermodynamic study indicated the spontaneous and endothermic nature of cesium adsorption on the amino-functionalized MWCNTs. (author)