Solvent-freely polymerizing catechol and paraformaldehyde to nitrogen-rich carbon for high-volumetric-performance supercapacitor

Abstract

Fabrication of nitrogen functionalized carbon with high nitrogen content (over 10 atom%) by a route with simplified and solvent-free procedures would be both economically and environmentally scalable. We demonstrate here a simple solvent-free route towards synthesizing porous carbon doped by nitrogen functionalties (21.7 atom%) involving solid state catalytic polymerization of catechol and paraformaldehyde with g-C3N4 as catalyst. Upon high-temperature treatment, the vaporized catechol and paraformaldehyde would be in situ polymerized on the surface of g-C3N4 forming the composite of g-C3N4@resin. During the following carbonization process, the resin was carbonized to carbon skeleton, while the g-C3N4 would be decomposed in situ doping the carbon skeleton. In our design, the avoidance of solvents in the whole synthesis procedure and the usage of g-C3N4 in the preparation not only reduces the waste production, but also introduces high nitrogen species (21.7 atom%). As electrode for supercapacitor, the resultant SFC based electrode achieves a large specific capacitance of 391F cm−3@1.0 A/g and high energy density of 34.5 Wh/L@1370 W/L, suggesting a potential as electrode for energy storage. And more, the developed method offers a promising and alternative route for the fabrication of new materials in manner of green and environmentally friendly.