silicon and hydrazine

We describe catalytic micromotors powered by remarkably low concentrations of chemical fuel, down to the 0.0000001% level. These Janus micromotors rely on an iridium hemispheric layer for the catalytic decomposition of hydrazine in connection to SiO2 spherical particles. The micromotors are self-propelled at a very high speed (of ~20 body lengths s(-1)) in a 0.001% hydrazine solution due to osmotic effects. Such a low fuel concentration represents a 10,000-fold decrease in the level required for common catalytic nanomotors. The attractive propulsion performance, efficient catalytic energy-harvesting, environmentally triggered swarming behavior, and magnetic control of the new Janus micromotors hold considerable promise for diverse practical applications.

Topics: Biofuels; Catalysis; Hydrazines; Iridium; Molecular Motor Proteins; Nanospheres; Particle Size; Silicon

Multireference as well as single-reference wave functions were adopted to study the surface reaction mechanisms of hydrazine. The initial surface mechanisms resemble those of ammonia and its methyl derivatives. MRMP2 values indicate that the lifetime of initial molecularly adsorbed species should be longer than previously suggested. High energy path as well as low energy path of subsequent surface reactions were found. The theoretical initial surface product of low energy path is consistent with the experimentally suggested structure. Both paths eventually lead to very stable surface products, which are also consistent with the experimentally suggested structures. The reaction channels of the experimentally observed NH3 desorptions were also revealed. It was shown that the high reactivity of hydrazine as compared to ammonia and its methyl derivatives is due to the high nucleophilic ability of the additional nitrogen atom of hydrazine.

Topics: Adsorption; Ammonia; Binding Sites; Computer Simulation; Hydrazines; Kinetics; Models, Chemical; Models, Molecular; Molecular Conformation; Phase Transition; Silicon; Surface Properties