Oxygen-doped activated carbons derived from three kinds of biomass: preparation, characterization and performance as electrode materials for supercapacitors

In this work, oxygen-rich activated carbon compounds were prepared from three kinds of biomass by simple carbonization and they were investigated as electrodes for supercapacitors. The selected biomasses were waste dragon fruit skin, Momordica grosvenori skin and Firmiana catkins. Three kinds of as-prepared activated carbons showed abundant oxygen-containing groups and typical amorphous characteristics with high specific surface areas of 911.2 m(2) g(-1), 597.5 m(2) g(-1) and 286.7 m(2) g(-1), respectively. This combination of high specific surface areas and abundant active surface functional groups resulted in capacitances of 286.9 F g(-1), 238.7 F g(-1) and 226.6 F g(-1) at 0.5 A g(-1), respectively. Furthermore, three kinds of as-prepared activated carbons also showed excellent cycling performance with nearly 100% retention over 5000 cycles at 4.0 A g(-1) in 2.0 mol l(-1) KOH solution. As a result, three kinds of as-prepared activated carbons exhibited favorable electrochemical performances in potential application as electrode materials for supercapacitors.