▎ 摘　　要

We demonstrate trifluoromethylation of graphene by copper-catalyzed free radical reaction. The covalent addition of CF3 to graphene, which changes the carbon atom hybridization from sp(2) to sp(3), and modifies graphene in a homogeneous and nondestructive manner, was verified with Raman spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. X-ray photoelectron spectroscopy reveals that CF3 groups are grafted to the basal plane of graphene, with about 4 at. % CF3 coverage. After trifluoromethylation, the average resistance increases by nearly one order of magnitude, and an energy gap of about 98 meV appears. The noninvasive and mild reaction to synthesize trifluoromethylated graphene paves the way for graphene's applications in electronics and biomedical areas. (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.