Figure 3

(a–h) TEM and HAADF-STEM images of the CoF2 NRs (a–c) and Co2P NRs (d–f) synthesized without OA [inset: HRTEM image of Co2P NRs (scale bar = 4 nm)]. For HAADF-STEM elemental mapping, the following color code was used: cobalt (red), fluorine (yellow) and phosphorous (blue). (g) Synthetic scheme presenting the reaction conditions for obtaining CoF2 and Co2P NRs and Co2P NPs. (h–k) TEM images of CoF2 NRs (h,i) and Co2P NPs (j,k) synthesized with OA.