Two-step preparation of hierarchical porous carbon from KOH-activated wood sawdust for supercapacitor

Abstract

Interconnected hierarchical porous carbons were synthesized via KOH-assisted hydrothermal pretreatment and carbonization of wood sawdust. KOH-assisted hydrothermal treatment can remove the lignin from sawdust and on the other hand, the presence of KOH facilitates the creation of macro and mesopores during the carbonization. Base-assisted hydrothermal treating time plays an important role in determining the pore structure of carbons, thus affecting their electrochemical performance. The resulting porous carbons show the highest specific capacitance of 303 F g−1 in a current density of 1 A g−1, high energy density of 17.75 W h kg−1 at a power density of 436 W kg−1, and an outstanding cycling stability. As a facile synthesis route for porous carbons from wood sawdust, such method has the potential to be directly used for industrial production, and the efficient uses of wood residue are important for sustainable development.