  Silicene is a two-dimensional material, which is composed of a single layer
of silicon atoms with sp2-sp3 mixed hybridization. The sp2-sp3 mixed
hybridization renders silicene excellent reactive ability, facilitating the
chemical modification of silicene. It has been demonstrated that chemical
modification effectively enables the tuning of the properties of silicene. We
now review all kind of chemical modification methods for silicene including
hydrogenation, halogenation, organic surface modification, oxidation, doping
and alloying. The effects of these chemical modification methods on the
geometrical, electronic, optical and magnetic properties of silicene are
discussed. The potential applications of chemically modified silicene in a
variety of fields such as electronics, optoelectronics and magnetoelectronics
are introduced. We finally envision future work on the chemical modification of
silicene for the sake of further advancing the development of silicene.
