Figure 5 : Atomic-resolution HAADF STEM images of (a) WS 2 and (b) Ni-promoted WS 2 nanostructures. Contrast is from W atoms only. Red dashed lines guide the eye to the edges of the sheet-like structures. (c) Plots of P/A ratios for the two samples. Blue and yellow DFT models of the metal sulphide structures indicate differences in edge-structure.
Figure 6 : Atomic-resolution HAADF STEM images of WS 2 nanostructures (a) sulfi ded at 413°C and (b) sulfi ded at 413°C + O 2 plasma treatment. Contrast is from W atoms only. Red dashed lines guide the eye to the edges of the sheet-like structures. (c) Plots of P/A ratios for the two samples. Blue and yellow insets are DFT models of the metal sulfi de, which indicate differences in edge-structure.