Figure 3: Structural characterizations on the Co-NG.
From: Atomic cobalt on nitrogen-doped graphene for hydrogen generation
(a) Bright-field aberration-corrected STEM image of the Co-NG showing the defective and disordered graphitic carbon structures. Scale bar, 1 nm. (b) HAADF-STEM image of the Co-NG, showing many Co atoms well-dispersed in the carbon matrix. Scale bar, 1 nm. (c) The enlarged view of the selected area in b. Scale bar, 0.5 nm. (d,e) The k2-weighted EXAFS in k-space and their Fourier transforms in R space for the Co-NG and Co-G, respectively. (f) Wavelet transforms for the Co-NG and Co-G. The location of the maximum A shifts from 3.2 Å−1 for Co-G to 3.4 Å−1 for Co-NG, indicating the presence of Co-N bonding in Co-NG. The vertical dashed lines are provided to guide the eye.
