Construction of Layered B3N3-Doped Graphene Sheets from an Acetylenic Compound Containing B3N3 by a Semisynthetic Strategy.

The structural modification of graphene at the atomic level is crucial for electrochemical applications. Doping heteroatoms to modify the structure of graphene has widely been adopted. However, the construction and controllable doping of heteroatom-doped graphene remains a challenge. Herein, a novel semisynthetic method is developed to synthesize a borazine (B3N3)-containing acetylenic compound as a precursor, and a series of B3N3-doped few-layered graphene nanosheets are prepared after annealing at different temperatures. To form graphene sheets, the in situ-forming MgBrCl salt is used as an intercalation agent to enlarge the mutual distance between molecules, which can inhibit the unwanted cross-linking reaction. Nanosheets with different thicknesses of 2.5, 3.5, and 4.1 nm can be obtained at annealing temperatures of 1500, 1200, and 1000 °C, respectively. The results demonstrate that the B and N atoms are co-doped in the graphene by the structure of B3N3, and the doping site can be changed with different annealing temperatures. The optical gap of graphene can be successfully opened by doping with B3N3, and the resultant material can be potentially utilized as a catalyst and semiconductor material. Furthermore, this new semisynthetic strategy will offer the opportunity to fabricate more carbon materials via controllable heteroatom doping.