In situ self-template synthesis of cobalt/nitrogen-doped nanocarbons with controllable shapes for oxygen reduction reaction and supercapacitors

Shape-controlled Co/N-doped nanocarbons derived from polyacrylonitrile (PAN) were synthesized by a one-step in situ self-template method followed by a pyrolysis procedure. This is the first study to tune the nanostructure of Co/N-doped carbon materials by providing a metal salt as the template and additive. The moderate surface area (699.47 m(2) g(-1)), highly developed pore structure, homogenous Co and N doping and designed "egg-box" structure impart Co/N-doped cross-linked porous carbon (Co/N-CLPC) with excellent electrocatalytic activity and capacitive performance. This material displayed an onset potential of 0.805 V (vs RHE), a current density of -5.102 mA cm(-2), excellent long-term durability, and good resistance to methanol crossover, which are comparable with the characteristics of a commercial 20-wt% Pt/C catalyst. In addition, Co/N-CLPC demonstrated a high specific capacitance of 313 F g(-1) at 0.5 A g(-1), notable rate performance of 63% at 50 A g(-1), and good cycling stability of 104.8% retention after 5000 cycles when used as a supercapacitor electrode. This method enables new routes to obtaining Co/N-doped nanocarbons with shape-controlled structures for energy conversion and storage applications.