Niobium- and cobalt-modified dual-source-derived porous carbon with a honeycomb-like stable structure for supercapacitor and hydrogen evolution reaction.

ABSTRACT

Designing porous carbon materials with tailored architecture and appropriate compositions is essential for supercapacitor (SC) and hydrogen evolution reaction (HER). Herein, Nb/Co-modified dual-source porous carbon (Nb/Co-DSPC) with a honeycomb structure was obtained by introducing a secondary carbon source (Co/Zn-ZIF) and transition metal Nb into activated Typha carbon (ATC). The addition of a secondary carbon source and Nb resulted in superior specific surface area (1272.38 m2/g), excellent hydrophilicity (34.73°) and abundant bimetallic active sites (Nb/Co-Nx) in Nb/Co-DSPC, providing excellent charge storage capacity and electrocatalytic activity. The Nb/Co-DSPC electrode displayed an outstanding capacitance of 337 F/g at 0.5 A/g and showed excellent stability after 15,000 charge-discharge cycles. In addition, Nb/Co-DSPC shows an overpotential of 114 mV at 10 mA cm-2, better than those of Co-DSPC (139 mV) and ATC (162 mV) alone. This study offers a reliable strategy for advanced multifunctional porous carbon electrode materials preparations.