Au could catalyze the growth of ZnO NWs in two possible ways depending on the related position of Au alloy droplets (nanoparticles) to the NWs. The growth was called tip-growth mechanism if the Au alloy nanoparticles were found at the tips of ZnO NWs (Fig. 1), whereas the growth was named base-growth mechanism if the Au alloy nanoparticles were found at the base of the ZnO NWs (Fig. 2).
(a)
(b)
(c)
Fig. 1 (a) Tip-growth Au-catalyzed ZnO NW, EDS analysis of NW at the (b) body and (c) tip.
(a)
(b) base
(c) body
(d) tip
Fig. 2 (a) Base-growth Au-catalyzed ZnO NW, EDS analysis of NW at the (b) base, (c) body and (d) tip.
[Reference: Pung, S. Y.;Choy, K. L.;Hou, X.; J. Crys. Growth 2010, 312, 2049 - 2055.]
