Low-temperature synthesis of few-layer graphene

• The few-layer graphene is synthesized at 95 °C.
• The synthesis mechanism of the materials relies on the Ullmann reaction.
• The synthesized graphene exhibits the reversible capacity of 570 mAh g−1.

Few-layer graphene was synthesized at 95 °C by the Ullmann reaction using acetylene as the raw material. Hexabromobenzene (HBB) and cuprous bromide were used as the catalyst in this reaction. A contrast experiment performed without HBB also confirmed this point. The resulting material was characterized by Raman spectroscopy and exhibited characteristic peaks of graphene. Moreover, the structure of the as-prepared material was confirmed as few-layer graphene by transmission electron microscopy, X-ray photoelectron spectroscopy and solid-state 13C nuclear magnetic resonance spectra. The synthesized graphene used as the anode of lithium-ion battery exhibited the initial and reversible capacities of 650 and 570 mAh g−1, respectively, which in accordance with the theoretical capacity of graphene.