▎ 摘　　要

The lack of a band gap has greatly hindered the applications of graphene in electronic devices. By means of dispersion-corrected density functional theory computations, we demonstrated that considerable CH/pi interactions exist between graphene and its fully (graphane) or patterned partially (C4H) hydrogenated derivatives. Due to the equivalence breaking of two sublattices of graphene, a 90 meV band gap is opened in the graphene/C4H bilayer. The band gap can be further increased to 270 meV by sandwiching graphene between two C4H layers. By taking advantage of the similar SiH/pi interactions, a 120 meV band gap also can be opened for silicene. Interestingly, the high carrier mobility of graphene/silicene can be well-preserved. Our theoretical results suggest a rather practical solution for gap opening of graphene and silicene, which would allow them to serve as field effect transistors and other nanodevices.