Graphene Oxide Coating Enhances the Adsorption of Lead Ions in Mesoporous SiO2 Spheres

Mesoporous silica has been widely used for wastewater treatment due to its high adsorption capacity in theory. However, limited by the adsorption–desorption equilibrium, it still remains a challenge to remove heavy metal ions from the polluted water. In this work, graphene oxide (GO)-coated mesoporous silica spheres were prepared by an electrostatic self-assembly method, and these showed excellent Pb(II) ion removal efficiency. The escape of Pb(II) ions adsorbed on mesoporous silica could be suppressed by the GO coating, resulting in the enhanced adsorption performance.