One-Step Synthesis of Hierarchical Micro-Mesoporous SiO2Reduced Graphene Oxide Nanocomposites for Adsorption of Aqueous Cr(VI)‎

Abstract EN

A novel micro-mesostructured SiO2/reduced graphene oxide (RGO) nanocomposite was successfully synthesized by means of simple one-step hydrothermal method under acidic conditions using tetraethoxysilane (TEOS) and graphene oxide (GO) as the raw material.

The nanocomposites were characterized by TEM, XRD, FT-IR, TG-DSC, and N2 adsorption-desorption.

The results showed that GO was partially reduced to RGO without adding any reducing agent and SiO2 nanoparticles (ca.

10 nm) were uniformly anchored on the surface of RGO.

The optimized composite contained 75 wt.% SiO2 and possessed hierarchical micro-mesoporous structure with surface area of 676 m2/g.

The adsorption performance of synthesized SiO2/RGO samples was investigated by removal efficiency of Cr(VI) ions in wastewater.

The Cr(VI) adsorption reached equilibrium in 30 min and 98.8% Cr(VI) adsorption efficiency was achieved at pH = 2 at 35°C.

Stability tests showed that SiO2 nanoparticles effectively prevented RGO from the restacking.

The mechanisms of composite formation and for Cr(VI) adsorption were suggested.