Nitrogen and Oxygen Co-doped Hierarchical Porous Carbon Derived from Pine Mushroom Biomass for High-Performance Supercapacitor

Due to the unique physicochemical properties, heteroatom doping of porous carbon has attracted wide attention. However, the complicated synthesis process and high cost limit its mass production. In this work, nitrogen and oxygen co-doped porous carbon materials (N-O-PCMs) derived from pine mushroom (PM) were prepared using a "one-step" carbonization and activation approach with potassium hydroxide (KOH) as active agent and at different PM/KOH mass ratios. The as-prepared hierarchical porous carbon materials are shown to not only contain rich N and O species, but also have an appropriate mesopore ratio and a narrow mesopore size distribution. Among all samples, the sample N-O-PCM-3 exhibits the largest specific surface area (935.8 m(2) g(-1)), greatest total pore volume (0.56 cm(3) g(-1)), highest content of oxygen (20.1 at.%) and nitrogen (4.9 at.%) as well as optimal hierarchical porous structure. The N-O-PCMs were tested in two electrode systems using 1 M Na2SO4 aqueous electrolyte. N-O-PCM-3 shows an energy density of up to 35.9 Wh kg(-1) at 360 W kg(-1) and an outstanding long-term stability (89.7 % after 10,000 cycles). This work proposes a facile and low-cost method for synthesizing multiple heteroatom-doped hierarchical porous carbon for supercapacitors.