Nitrogen and Sulfur Co–Doped Hollow Carbon Nanospheres Derived from Surface‐Attached Polyelectrolyte Monolayers

Abstract

AbstractNitrogen, sulfur co‐doped hollow carbon nanospheres are synthesized by simple pyrolysis of surface‐attached 2‐thiophene acetic acid neutralized poly(4‐vinylpyridine) monolayers on silica nanoparticles, followed by removal of silica templates. The covalently grafted polymer chains prevent the aggregation of silica templates during pyrolysis process, resulting in well‐distributed mesopores. The formed materials exhibit an improved electrocatalytic performance for oxygen reduction reactions under basic conditions compared to nitrogen doped hollow carbon nanospheres in terms of the positive shift of half‐wave potential. The best catalytic activity is observed for the material with surface area of 489 m2g−1 derived from 15 nm silica templated modified with polymers, which is comparable to commercial 20 wt.% Pt/C catalysts (half‐wave potential negatively shifts by 10 mV with similar limiting current density compared with Pt/C catalysts). Although the dual doping can improve the catalytic activity, the increase in sulfur concentration of the formed materials has little effect on the electrocatalytic performance for oxygen reduction reactions. This development offers a new synthetic strategy to synthesize heteroatoms co‐doped or multi‐doped spherical hollow carbon materials not only for application in electrochemical devices, but also as model materials for fundamental understanding of properties of carbon‐based materials.