One-step carbonization production of B/N co-doped carbon from polyurethane/phenolic/GO composite for supercapacitors

We report a facile approach which used common polymer materials to assemble a new type of B/N co-doped carbon materials through one-step carbonization from waterborne polyurethane (WPU), phenolic resin (PF) and graphene oxide (GO). During the process of synthetic WPU and WPU/PF/GO composite (WPGC), the nitrogen content was up-regulated by the addition large quantity of melamine. Moreover, nitrogen heteroatom had successfully added into the WPGC due to repetitive urethane bond (–NHCOO) from WPU as nitrogen-enriched carbon. Furthermore, the B–N bonds were decreased by ferric catalyst treatment and many micropores and small mesopores were formed from the boric acid and washing treatments. The WPGC/Fe/B as supercapacitor electrode exhibited a high specific capacitance of 340.5 F g−1 at 0.5 A g−1, well rate performance, superior cycling stability, with the surface area, and pore volume (670.2 m2 g−1 and 0.3458 cm3 g−1). More remarkably, since the WPGC/Fe/B electrode showed high capability, the fabricated symmetric supercapacitor exhibited a good power density (8.58 Wh kg−1 at 492 W kg−1) and indicated outstanding cycle stability (90.56% capacitance retention after 5000 cycles at 5 A g−1) in 6 M KOH electrolyte. The work will develop a novel method to synthesize carbon-based electrode for applications in supercapacitors.