Nitrogen-doped porous carbon microsphere with high surface area for supercapacitors and capacitive deionization

Heteroatom-doped porous carbon materials have attracted extensive attention because of their great potential in improving electrochemical properties. In the present study, based on a simple carbonization process followed by steam activation, we successfully prepare a nitrogen-doped porous carbon employing pyrrole–formaldehyde polymer microsphere as a precursor. The as-prepared activated nitrogen-doped carbon microsphere (ANCM) displays a spherical structure with micro/meso pores and a large surface area value of 1880 m2 g−1. The obtained ANCM-based supercapacitor, constructed with a two-electrode configuration, shows a high specific capacitance value of 181 F g–1 (0.1 A g–1) in 1.0 mol L–1 H2SO4 and retained over 80% of its capacitance at high current density (10.0 A g–1). Furthermore, capacitive deionization measurements find that the ANCM electrode achieves an adsorption amount of 13.3 mg g–1 in 500 mg L–1 NaCl. The results present the potential of the as-prepared nitrogen-doped porous carbon materials from pyrrole–formaldehyde polymer microsphere as candidate electrodes for supercapacitor and desalination applications.