Figure 3

(a) TEM images of FeS₂ NCs, the average size is 20 nm. The insets show HRTEM images of FeS₂ NCs and clear selected area electron diffraction image indicates single crystal of FeS₂ NCs. (b) XRD of FeS₂ NCs film. (c-f) XPS spectrum of FeS₂ NCs film.