Fig. 5: Raman analysis of graphene hydrogenated for 10 s and 60 s.

a Statistical distributions of D peak frequencies (w_D) of h-G on copper and water. Hydrogenation time was 10 s. b Statistical distributions of I_D/I_G ratios of hydrogenated graphene (h-G) on copper and on water after etching the copper. Hydrogenation time was 10 s. c Correlation map of G and 2D peaks frequencies of non-treated graphene on copper, non-treated graphene on water, h-G on copper and h-G on water. Hydrogenation time was 10 s. d Statistical distributions of D peak frequencies (w_D) of h-G on copper and water. Hydrogenation time was 60 s. e Statistical distributions of I_D/I_G ratios of hydrogenated graphene (h-G) on copper and on water after etching the copper. Hydrogenation time was 60 s. f Correlation map of G and 2D peaks frequencies of non-treated graphene on copper, non-treated graphene on water, h-G on copper and h-G on water. Hydrogenation time was 60 s.