Figure 3

(a) TEM image of hexagonal Ni doped CoOOH nanorings; (b) HAADF STEM image and its corresponding EDX mapping of O, Co and Ni. (c) TEM image and FFT of part of the nanorings and (d) its corresponding lattice image; (e) EELS of O-K edge and (f) Co-L and Ni-L edges.