Synthesis of ultra-thin graphene-like nanosheets from lignin based on evaporation induced self-assembly for...

Graphene-like carbon materials are widely used in power devices due to their excellent structural characteristics. In this study, ultra-thin graphene-like nanosheets (LGLNs) with rich surface wrinkles were prepared by classical evaporation induced self-assembly (EISA) using lignin biomass as carbon precursor, followed by chemical activation with KHCO₃. The obtained LGLN₉₀₀ material calcined at 900 °C had a thickness of ca. 3 nm, a large specific surface area of 2886 m² g^-1 with a high specific pore volume of 2.10 cm³ g^-1. In addition, a large number of wrinkles on the surface of LGLN₉₀₀ endows its effective compression resistance. When the LGLN₉₀₀ material was used as electrode material of supercapacitor, a high specific capacitance of 388 F g^-1 was obtained at 0.2 A g^-1 current density in 6 M KOH aqueous solution, and 269 F g^-1 specific capacitance could be at remained at 40 A g^-1. The supercapacitor assembled with LGLN₉₀₀ afforded a specific energy density of (11.0-13.7) Wh kg^-1 at a power density of (128.8-6465) W kg^-1. This work provides a facile and green strategy for the synthesis of highly wrinkled ultra-thin graphene-like nanosheets from sustainable biomass resources, which should have wide applications in adsorption, catalysis and energy storage.