Figure 3. Growth mechanism and structural tuning.

Typical TEM images of hierarchical Pt₃Co NWs intermediates collected from (a) 0.5, (b) 1, (c) 3 and (d) 5 h. (e) PXRD patterns of hierarchical Pt₃Co NWs intermediates collected from the reactions at different reaction times. (f) The composition ratio changes of Co to Pt for the hierarchical Pt₃Co NWs intermediates, as determined by ICP-AES measurements. Typical TEM images and HAADF-STEM images of (g–h) hierarchical Pt₃Co NWs, (i,j) hierarchical Pt₇Co NWs and (k,l) hierarchical Pt₁₀Co NWs collected from 8 h reactions. The scale bars in a–d, g, i and k are 20 nm. The scale bars in h,j and l are 100 nm.