Silk gel-based N self-doped porous activated carbon as an efficient electrocatalyst in neutral, alkaline and acidic medium

Abstract The nitrogen (N) self-doped porous activated carbons (SGC-T) are synthesized from silk gel at different carbonization temperature. Among of SGC-T, as-prepared SGC-900 exhibits outstanding oxygen reduction reaction (ORR) electrocatalytic activities in neutral, alkaline and acidic medium attributed to the synergistic effect of graphitization and active sites. And the high specific surface area (476.42 m2 g−1), pore volume (1.06 cm3 g−1), pore diameter (12.72 nm), degree of graphitization (90.16 at. % of C) and content of ORR active N (1.80 at. % of N-ORR: including pyridinic-N and graphitic-N) for SGC-900 provides suitable graphite structure to electron transfer and exposes many more active sites to participate in the process of ORR. Reasonably, SGC-900 displays superior ORR activity, stability and anti-poisoning in 50 mM PBS, 0.1 M KOH solution and 0.5 M H2SO4 solution through more efficient electron pathway. Furthermore, SGC-900 indicates excellent ORR performance in the practical application of microbial fuel cell (MFC) with high output voltage (498.66 ± 10.19 mV) and maximum power density (507.13 ± 7.06 mW m−2). These results suggest, as one activated carbon (AC), SGC-900 possesses broad application prospects in the field of fuel cells.