Biomass waste derived heteroatom doping porous carbon sheets for high performance supercapacitor

Abstract

Porous carbon sheets exhibit a big open flat layer with large surface area, short ion transfer distance, which has attracted massive research as electrode materials for supercapacitors. Here, O, N, and P co-doped porous carbon sheets (ONPC) were developed by one-step activation way using sunflower straw as the carbon source, NH4H2PO4 as phosphorus the source, and nitrogen source, and then activated by KHCO3. Benefiting from the suitable specific surface area and massive O (13.98 at%), N (7.43 at%), and P (0.81 at%) functional groups, the ONPC-700 electrode exhibits a specific capacitance of 340 F g−1 at 0.5 A g−1, superior electrochemical stabilization with the capacitance retention rate of 100.5% after 10,000 cycles. More interestingly, the assembled symmetric supercapacitor (ONPC-700//ONPC-700) achieves an energy density of 22.0 Wh Kg−1 and superior electrochemical stabilization. The above excellent results indicate that this paper offers a feasible and simple strategy for preparing biomass-based heteroatom doped porous carbon sheets for supercapacitors.