Nitrogen adsorption isotherm analysis reveals a Brunauer–
Emmett–Teller (BET) surface area of up to 547 m2 g21 for the CNF aerogel, which is much higher than that of N-doped graphene framework (280 m2 g21)33 and monolithic graphene aerogels
(249 m2 g21)45 (see Supplementary Information, Fig. S5).