(a-c) The bird's-eye view of SEM images of Au tube deposited on an ordered array of Si nanowires. The rectangle in (a) encloses a region which is magnified into (b), and the rectangle in (b) encloses a region which is magnified into (c). (d) EDX spectrum of an Au tube/Si nanowires sample. (e) HR-TEM image of an Au tube released from Si nanowire, and (inset of e) the  zone axis SAED pattern of the Au tube. The white lines indicate projection of atoms on (111) plane along  direction. (f) Applied potentials versus deposition times for the deposition in the dark (black line) and under room light illumination (gray line), respectively.