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

Summary 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.