Quantitative Super-resolution Imaging Uncovers Reactivity Patterns on Single Nanocatalysts

1. Quantitative Super-resolution Imaging UncoversReactivity Patterns on Single Nanocatalysts Daniel C. Ralph, Cornell University, ECCS 0335765 Metal nanoparticles are used as catalysts in a variety of important chemical reactions and can have a range of different shapes, with facets and sites that differ in catalytic reactivity. To develop better catalysts it is necessary to determine where catalysis occurs on such nanoparticles and what sites are most reactive. The Peng Chen group at Cornell has used the capabilities of the Cornell NanoScale Facility to help quantify the catalysis of individual gold nanorods at a spatial resolution of ∼40 nm using super-resolution fluorescence microscopy. They find that within the same surface facets on the sides of a single nanorod, the reactivity exhibits a gradient from the centre of the nanorod towards its two ends. Furthermore, the ratio of the reactivity at the ends of the nanorod to the reactivity at the sides varies significantly between nanorods. This work shows that defects on the surface of the nanorod provide the most reactive catalytic sites. (top) Schematic of the super-resolutions fluorescence microscopy technique to measure catalytic activity. (bottom) Map of catalytic activity for a single gold nanorod. Peng Chen group, Cornell University. Work performed at the Cornell NanoScaleFacility X. Zhou et al., Nature Nanotechnology 7, 237 (2012)