Functionalization is a well-established method to manipulate the electronic properties of graphenes
It consists in the substitution of carbon atoms in the hexagonal network by other elements such as heteroatoms (nitrogen or boron, the most common) or in the introduction of more complex functional groups.
The customization of the graphene exceptional electronic properties by the functionalization opens different avenues for future applications including bio and chemical-sensors. Among various functionalization methods, plasma process and ion irradiation have been widely employed for the modification of surface chemical composition and properties. These techniques have attracted the attention of a vast scientific audience because they can be used to tailor the surface reactivity in different materials making them suitable for various applications ranging from chemical sensing to medical implants. In particular, the fluorination of graphene allows the tuning of the optical bandgap, introducing a progressive semiconducting behaviour for increasing fluorine content ending in insulating properties for fully fluorinated graphene.