Biomass-derived O, N-codoped hierarchically porous carbon prepared by black fungus andHericium erinaceusfor high performance supercapacitor

Abstract

Biomass-derived carbon materials have been widely researched due to their advantages such as low cost, environmental friendliness, readily available raw materials. Black fungus andHericium erinaceuscontain many kinds of amino acids. In this paper, unique O, N-codoped black fungus-derived activated carbons (FACX), andHericium erinaceus-derived activated carbons (HACX) were prepared by KOH chemical activation under different temperatures without adding additional reagents containing nitrogen and oxygen functional groups, respectively. As electrode materials of symmetric supercapacitors, FAC2and HAC2calcined at 800 °C exhibited the highest specific capacitance of 209.3 F g−1and 238.6 F g−1at 1.0 A g−1in the two-electrode configuration with 6.0 M KOH as the electrolyte, respectively. The X-ray photoelectron spectroscopy confirmed that the as-synthesized FACXand HACXcontained small amounts of nitrogen and oxygen elements. Moreover, heteroatom-doped FAC2and HAC2electrode materials shown excellent rate performance (84.1% and 75.0% capacitance retention at 20 A g−1, respectively). By comparison, the oxygen-rich hierarchical porous carbon (HAC2) shows higher specific capacitance and energy density and longer cycling performance. Nevertheless, carbon-rich hierarchical porous carbon (FAC2) indicates excellent rate performance. Biomass-derived heteroatom self-doped porous carbons are expected to become ideal active materials for high performance supercapacitor.