Properties of photochlorinated graphene

We report the synthesis and electronic properties of chlorinated graphene, a totally new graphene derivative. The gas-phase photochlorination of graphene, followed by the structural transformation of the C-C bonds from sp² to sp³ configuration, could remove the conducting π-bands and open up a band gap in graphene. After chlorination, the resistance of graphene increases over 4 orders of magnitude. Moreover, the resistance of chlorinated graphene shows a significant temperature dependence. Electrical transport in chlorinated graphene is well described by variable range hopping in two dimensions due to the presence of localized states in the band gap. The facile, highly efficient and patternable photochlorination method offers a feasible pathway to engineer the band structure of graphene.