Journal of Colloid and Interface Science, Vol.348, No.2, 335-341, 2010
Catalytic gold nanoparticle driven pH specific chemical locomotion
Gold nanoparticle (Au NP) catalyzed decomposition of alkaline hydrogen peroxide has been utilized in driving chemical locomotives in a liquid. Au NPs deposited on spherical micron sized polymer resin beads catalyzed the decomposition of H2O2 in the pH range 9.1-10.8. The O-2 gas bubbles produced in the decomposition moved the beads upward with average velocities that depended on the pH of the solution. The measured average velocity of the bead increased with the increase in pH in the range 9.1-10.8. Above this pH, the self-decomposition of H2O2 produced sufficient bubbles in the medium that made the motion haphazard and thus prevented a clear measurement of the velocity. The observed accelerated motion of the locomotive has been explained by considering the time-dependent growth of O-2 gas bubbles on the polymer, while taking into consideration desorption and other factors. (C) 2010 Elsevier Inc. All rights reserved.