A sustainable strategy to prepare porous carbons with tailored pores from shrimp shell for use as supercapacitor electrode materials

The highly efficient synthesis of nitrogen-doped carbons with different pore structures is reported using shrimp shell as the carbon and nitrogen source, and its CaCO3 component as the hard template and activator. The CaCO3 content of shrimp shells can be easily changed by changing the leaching time to remove it. CaCO3 acts as the activator and template to tailor the pore sizes of the carbons. CO2 from the decomposition of CaCO3 also plays an activating role. Their specific surface areas, pore volumes, ratios of micropore volume to total pore volume can be adjusted in the ranges 117.6-1 137 m2 g−1, 0.14-0.64 cm3 g−1, and 0-73.4%, respectively. When used as the electrodes of a supercapacitor, the porous carbon obtained with a leaching time of 92 min has a high capacitance of 328 F g−1 at 0.05 A g−1 in a 6 mol L−1 KOH electrolyte and 619.2 F g−1 at 0.05 A g−1 in a 1 mol L−1 H2SO4 electrolyte. Its corresponding energy density at a power density of 1 470.9 W kg−1 is 26.0 Wh kg−1. This study provides a low cost method for fabricating porous carbons from biomass with a high added value.