A Strategy to Produce Single and Double Layer Graphene Sheets
We report an easy and scaleable approach to produce single and double layer graphene (Gr)-sheet from re-exfoliation of expanded graphite (EG) with large area. Transmission and scanning electron microscopic observations show that the Gr-sheets have an area of ~ (12 x 10) μm2. Raman spectroscopy has confirmed the presence of single and double layer Gr-sheet with I2D/IG ratio as ~ 1.7. Scanning probe microscopy studies reveals that on re-exfoliation of EG, thickness of Gr-layer decreases from 6-7 nm to 0.8-1.1 nm. This infers that re-exfoliation overcomes the problem of insufficient oxidation or inadequate pressure buildup during heat treatment.
Shiquan Liu and Min Zuo
S.R. Dhakate et al., "A Strategy to Produce Single and Double Layer Graphene Sheets", Advanced Materials Research, Vols. 306-307, pp. 1435-1439, 2011