Figure 1: Electron microscopy of the Ni/N-CNT.

(a) SEM image. Scale bar, 100 nm. (b) TEM image. Scale bar, 100 nm. Inset is selected area electron diffraction pattern. (c) A magnified TEM image. Scale bar, 20 nm. (d) HRTEM images of nickel particle and CNT, respectively. Scale bars, 2 nm.