(a) Top and (b) cross-sectional SEM images of the multilayered Ni/Pt NW arrays; (c) XRD patterns of the multilayered Ni/Pt NW arrays before and after oxidization; (d) HAADF–STEM image of NiO_x/Pt NWs oxidized at 600°C and elemental maps of (e) Ni, (f) O, and (g) Pt.^[92] Reproduced by permission of The Royal Society of Chemistry.