Initial stages of graphene oxide cracking in basic media

Despite the increasing interest in graphene oxide (GO) and its properties, currently there is no consensus on its structure. In the recently proposed two-component model, the GO structure consists of slightly oxidized graphene sheets and small organic molecules physisorbed on them. The formation of these molecules has been later attributed to the GO rupture caused by basic treatment under heating. In this work, we studied the initial stages of the GO rupture in hydroxyl chains by using first principles electronic calculations. Possible routes to cracking originated from different configurations of hydroxyl chains and under possible reactions in basic media were analyzed. Resulting from successive hydroxide ion attacks, cracks were observed for chains with hydroxyls arranged in armchair and zigzag configurations. Bond breaking due to the presence of ketones located at opposite sides of the basal plane was shown to play a role on cracking initiation and propagation. Cracking driven by structural deformations was also observed for chains comprised of parallelly orientated vicinal diols.