Figure 1: Structural and morphological characterization of Co3O4 films.

Scanning electron micrographs in low (a) and high magnification (c), transmission electron micrograph (b) and selected area electron diffraction (SAED) pattern (d) of as-prepared Co3O4 films. Diffraction rings of Co3O4 are indexed in the SAED pattern. The scale bars represent 2 μm, 50 nm, 100 nm and 5 nm−1 in panel a,b,c and d respectively.