In this work, porous silica gel-solid beads have been made from economically affordable water–glass precursors via sol–gel nano casting technique. A stable nanometric silica sol was prepared first from water glass and studied for surface potential and sol to gel transition. A free-flow, injectable gel was obtained upon aging the sol which was then assembled into spherical silica beads in a chemical bath. A surface area of 304.7m 2 g −1 was obtained for water glass derived silica gel beads. These gel beads were impregnated with 3-aminopropyltrimethoxysilane (APTMS) and polyethylenimine (PEI) active functional groups at different percentages for turning the gel beads as sorbents for CO 2 gas adsorption. The effect of amine loading on the thermal stability, morphology as well as porosity was studied and was correlated with CO 2 adsorption values. Depending upon the amount of amine loaded in the gel support CO 2 uptake was found varied. These amine modified silica gel porous adsorbents showed CO 2 adsorption capacity at temperatures as low as 100°C; samples modified with 15wt% PEI had CO 2 adsorption capacity of 1.16mmolg −1 at 50°C.