Interconnected micro-mesoporous carbon nanofiber derived from lemongrass for high symmetric supercapacitor performance

Abstract

The hierarchical porous activated carbon nanofiber has been prepared and characterized from the biomass based of lemongrass leave waste (LG). The preparation process used a simple technique through impregnation of ZnCl2 with low concentrations (0.5, 0.7 and 0.9) mol/L. These three concentrations were chosen to maximize the potential of LG to produce carbon nanoporous structures with high surface area. The preparation of activated carbon is performed by a one-step technique, including carbonization and physical activation at a temperature of 800 °C in N2/CO2 atmosphere. The three sample variations resulted in a very good amorphous structure according to the XRD pattern. The sample LG-0.7 has been known to have the best physical and electrochemical properties with an SSA reaching 1694 m2 g−1 with a carbon content of 90.38%. Uniquely, the LG-0.7 sample has a combined morphological appearance of hierarchical pores such as sponges and nanofiber pores. This combined pore strongly supports the electrochemical properties of the carbon electrode with 256 F g−1, a specific energy of 35.6 Wh kg−1 and a power density of 128.3 W kg−1 obtained using the GCD method. Electrochemical testing was carried out at a low potential of 0–1 V with a scan rate of 1 mV s−1 under the influence of an aqueous electrolyte of 1 M H2SO4. These results demonstrate the tremendous potential of lemongrass leaf waste as a raw material for the produce of porous carbon electrodes for high-performance supercapacitors.

Keywords

• Hierarchical porous
• Nanofiber
• High surface area
• Porous carbon electrode
• Supercapacitors