Figure 4: FeOx/graphene hybrid material.
(a) An SEM image of the FeOx/graphene hybrid. Scale bar, 200 nm. (b) An X-ray diffraction spectrum of a packed thick film of FeOx/graphene. (c) An XPS spectrum of the FeOx/graphene hybrid. (d) A TEM image of FeOx/graphene showing two types of particles grown on graphene. Scale bar, 100 nm. (e) A selected area diffraction pattern of small nanoparticles on graphene in the red circled area of (d). Scale bar, 2 nm−1. (f) A selected area diffraction pattern of a large nanoparticle on graphene in the blue circled area of (d). Scale bar, 10 nm−1. (g) High-resolution TEM image of small Fe3O4 nanoparticles grown on graphene. Scale bar, 5 nm. (h) XANES spectra of the FeOx/graphene hybrid and the graphene control sample at carbon K-edge. Blue dashed lines mark the graphene π* absorption at 285.5 eV, carboxyl π* absorption at 288.5 eV, and graphene σ* absorption at 291.8 and 292.7 eV. (i) XANES spectra of the FeOx/graphene hybrid and the FeOx control sample at iron L-edge. The inset shows XANES spectra at oxygen K-edge.
