Stabilizing graphene layers by intercalating laponite between them

The reduction of graphene oxide (GO) leads to the re-stacking/agglomeration of graphene layers, which results in their precipitation from an aqueous dispersion. A laponite colloid was used to prevent re-stacking and stabilize an aqueous dispersion of reduced graphene oxide (RGO) by dispersing GO in the colloid, followed by reduction with hydrazine hydrate under microwave radiation. Results indicate that re-stacking is prevented as proven by the disappearance of the RGO (002) peaks in the XRD pattern. A laponite/RGO (w/w: 1:1) dispersion shows the highest stability under centrifugation at 10 000 rpm and the largest Brunauer-Emmett-Teller surface area, which is 17.6% higher than that of RGO and 34.4% higher than laponite. Electrostatic interaction between negatively-charged RGO layers and positively-charged laponite edges lead to an intercalation structure, which is responsible for the non-stacking RGO and its stable dispersion in water. This intercalation method offers an alternative way for the dispersion of graphene layers.