A green route to synthesize nitrogen-enriched graphene-like carbon nanosheets from bio-oil for supercapacitors

Abstract Two-dimensional carbon materials with the combined characteristics of high surface area, plentiful exposed active sites as well as short ion transport distance, have received great attention for fast charge storage. Herein, an environmentally-friendly method is proposed for the fabrication of nitrogen-enriched graphene-like carbon nanosheet (NCS) from bio-oil by using graphitic carbon nitride (g-C3N4) as a self-sacrificing template and nitrogen source. Notably, compared with our previous work, the obtained carbon material possesses higher nitrogen content (8.09 at.%). Meanwhile, the carbon nanosheets have a much thinner thickness (~2.8 nm), large size and high electrical conductivity (85 S m−1). Consequently, the energy density of the symmetric supercapacitor displays high energy density of 10.6 W h kg−1 at a power density of 131.1 W kg−1 in 1 M H2SO4. This study proposes an eco-friendly and low-cost route for the preparation of graphene-like carbon materials for high-performance supercapacitors.