▎ 摘　　要

Controlled reduction of graphene oxide (GO) is a promising method to tune the electronic band gap of this two-dimensional material in the energy range of the visible light spectrum. By means of ab initio calculations, based on density functional theory at the generalized gradient approximation level, we investigated electronic properties of partially reduced graphene oxide, modelled as periodic array of small islands of pristine graphene embedded in an infinite sheet of GO. The calculations demonstrated that, by varying the size of the graphene islands from two to eight carbon atoms, it was possible to tune the electronic band gap in a range from 4.38 to 1.31 eV, which is of great importance to the utilization of graphene-based materials in photonic devices.