Synthesis of a graphene oxide/sodium silicate nanocomposite using sodium silicate solution

Abstract

Silicon alkoxide is the typical precursor used in the synthesis of graphene–silica composites; however, it is a toxic and relatively expensive material. Sodium silicate solution, on the other hand, is used industrially as a precursor in sol–gel processes for the production of silica. It is water-soluble and cheaper than silicon alkoxide and may be a suitable replacement in the preparation of graphene–silica composites. Graphene oxide/sodium silicate (G-O/Na₂SiO₃) sols were prepared from different concentrations of sodium silicate solutions and the pH of the sols was varied using HCl. The most stable G-O/Na₂SiO₃ sol was formed at pH 11, using 0.1 g of sodium silicate solution. We confirmed that the rG-O/Na₂SiO₃ nanocomposite contains particles with irregular shapes and sizes of a few hundred nanometers. The rG-O/Na₂SiO₃ nanocomposite also exhibited the highest electrical conductivity of 35.4 S cm⁻¹.