Fig. 2
Structure of the high-quality nitrogen-doped mesoporous graphene (HNMG) particles. a, b SEM and TEM images of mesoporous MgO particles. Scale bars: a 5 μm; b 100 nm. c, d element mapping of Mg, O, C, and N of a MgO particle after CVD deposition. Scale bars: c 2.5 μm; d 2.5 μm. e SEM, f, g TEM, and h high-resolution TEM images of the HNMG particles. The inset in h is the selected area electronic diffraction (SAED) pattern of the HNMG particle. Scale bars: e 2 μm; f 1 μm; g 20 nm; h 5 nm; inset of h, 5 1/nm. i Pore size distributions of MgO particles, MgO particles with deposited graphene, and HNMG particles. j XRD patterns and k Raman spectra of HNMG particles, NMG particles, and Graphite
