fig1

Figure 1. Microscopy of the pristine materials. (A) Scanning electron microscopy (SEM) micrograph of ZIF-67; (B and C) SEM micrographs of Mn-ZIF-67 at different magnifications; (D) Mn-ZIF-67 image and the corresponding EDS elemental maps for C, N, O, Mn and Co; all elemental maps were acquired from the same field of view and are displayed at the same spatial scale as the accompanying original image; (E) TEM micrograph with the corresponding selected-area electron diffraction (SAED) pattern in the inset; (F) HRTEM view and an enlarged lattice-fringe region; and (G) composite Mn/Co map acquired from a single Mn-ZIF-67 particle. TEM: Transmission electron microscopy; HRTEM: high-resolution transmission electron microscopy; ZIF-67: zeolitic imidazolate framework-67.