Temperature-directed growth of highly pyridinic nitrogen doped, graphitized, ultra-hollow carbon frameworks as an efficient electrocatalyst for the oxygen reduction reaction

Abstract

We report here the successful synthesis of highly pyridinic nitrogen doped, graphitized, ultra-hollow carbon frameworks (N-HCF-Ts, where T stands for the carbonization temperature) via a template-free temperature-directed growth route, using dicyandiamide and glucose as precursors. N-HCF-Ts have ultra high pyridinic nitrogen contents (up to 14.9 wt%), abundant meso–macropores, large specific surface areas (897–1434 m² g⁻¹), and ultra large pore volumes (4.47–8.47 cm³ g⁻¹). The structural characteristics of the ultra high pyridinic nitrogen sites, abundant meso–macropores, and graphitized and ultra-hollow frameworks make N-HCF-Ts highly efficient and stable electrocatalysts for the oxygen reduction reaction. The most positive reduction potential was evident for N-HCF-900 at 0.83 V (vs. the RHE), which is even comparable to that of commercial (20 wt%) Pt/C and much better than those of most of the various nitrogen doped carbon-based metal-free electrocatalysts.