Au–Fe/Ni alloy hybrid nanowire motors with dramatic speed†
Au–Fe/Ni alloy nanowire motors, having an average length of 5.4 ± 1.2 μm and a diameter of 280 ± 10 nm, can move fast in a mixed fuel containing H2O2 and N2H4. The powered motion is attributed to the bubble thrust produced from catalytic decomposition of hydrogen peroxide on the Fe/Ni alloy segments, while hydrazine seems to act as a co-catalyst. The regulation of speed can be achieved by modulating the proportion of alloy composition, and the highest speed obtained is up to 850 μm s−1 (ca. 157 body-length per s), which is the fastest among all nanowire motors. Because of the ferronickel segment's magnetism, the Au–Fe/Ni alloy nanomotors also can be guided by the magnetic force, in addition to being controlled by the propelling force generated by the bubble thrust.