Fluorination of Black Phosphorus-Will Black Phosphorus Burn Down in the Elemental Fluorine?

Black phosphorus (BP) represents a promising tunable bandgap alternative to graphene and other 2D materials in the field of semiconductors. However, its reactivity toward covalent modification of its surface (as a key to its bandgap adjustment) is scarcely reported. Here a method of covalent modification of BP involving reaction with fluorine is reported. Other allotropes of phosphorus are known to react violently with fluorine resulting in its complete burning down and formation of gaseous phosphorus pentafluoride. The results of our fluorination experiments conducted in analogy to the procedures used for fluorination of graphene indicate a successful binding of fluorine to BP. This route of modification of BP opens new possible ways toward covalent modification of the surface of this promising material.