The role of hydrazine in mixed fuels (H2O2/N2H4) for Au-Fe/Ni nanomotors

We previously introduced a novel Au-Fe/Ni alloy nanomotor that could move with a speed of up to 850 mu ms(-1) in a mixed fuel (H2O2 and N2H4) environment. However, the propulsion mechanism and the role of hydrazine were not fully elucidated. To this end, Tafel plots, linear sweep voltammetry (LSV) and oxygen sensing were employed and integrated to explore hydrazine's function and explain the locomotive behaviour of Au-Fe/Ni nanomotors. It was found that the speed of Au-Fe/Ni nanomotors was not positively correlated with the mixed potential difference between the composite metal pair, which had not been found in similar self-electrophoresis propelled nanomotors. Moreover, the results showed that the oxidation of H2O2 can also be facilitated by hydrazine in mixed fuels, resulting in oxygen bubbles propelling Au-Fe/Ni nanomotors forward.