However, the presence of water and Mn(VII) (3:1 molar ratio) leads to the formation of O3, which degrades into •O• and especially HO• (by the further reacting of O3 with H2O) . These radicals are highly reactive and, when in the presence of graphene, will react promptly forming a hydroxylgroup-rich structure. For this reason, temperature control is essential to avoid random reactions and for promoting selective functionalization. In sum, many functionalization variations can be applied to graphene using simple modifications of the classic chemical oxidation processes, enabling scaling-up the production of interesting new applications of modified graphene such as 2D electrolytes .