corresponding to the d-spacings of 0.335 nm and 0.168 nm respectively.
For o-EG, the (002) peak was observed at 2h = 29.83, corresponding
to the basal spacing of 0.347 nm and at the same time the
respective peak was broadened with very less intensity compared
to the (002) peak of NG. The shifting of the (002) peak towards
lower 2h value indicates separation and partial exfoliation (incomplete
exfoliation) of graphite sheets. Another two peaks, (100) and
(101) were appearing at 2h = 49.48 and 51.33 after thermal
expansion following the oxidation of EG, which correspond to the
2D in-plane symmetry along the graphene sheets [31,32]. For
i-MG, the (002) peak and the other peak’s positions were almost
same compared to the o-EG