Enhancing the\nSelf-Propelled Motion of Hydrogen Peroxide\nFueled Active Particles with Formic Acid and Other Oxygen Scavengers

We report enhanced active particle motion in hydrogen\nperoxide-fueled\nself-diffusiophoretic active particle systems of up to 400% via addition\nof low concentrations of oxygen scavenging agents such as formic acid\n(as well as other organic acids, hydrazine, and citric acid), whereas\nactive motion was inhibited at higher concentrations. Control experiments\nshowed that enhanced motion was decoupled from catalytic hydrogen\nperoxide decomposition rate and insensitive to particle surface chemistry.\nExperimental results point to bulk oxygen scavenging as the cause\nfor the enhanced active motion, representing a realization of recently\npredicted promotional effects of product sinks on self-diffusiophoretic\nmotion. Diminished active motion at high oxygen scavenger concentrations\nwas attributed to catalytic site blocking by adsorbed solute.