The excitation of localized surface plasmons (collective oscillations of conduction electrons) in metal nanostructures produces enhanced local electromagnetic fields, hot carriers and heat that can be used for surface-enhanced Raman spectroscopy (SERS) and photocatalysis. We are exploring novel strategies to deterministically assemble gold and silver nanocrystals into monodisperse colloidal dimers with well-defined hot spots and more complicated, reconfigurable structures with interesting plasmonic properties. We are also studying the photophysics of multi-metallic nanocrystals and utilizing supported nanocrystals as catalysts in benchtop photoreactor investigations of plasmon-driven chemical reactions.
The slide above summarizes some of our ongoing work in this area. The video below show the serial assembly of gold nanocrystals into chiral nanopropellers and nanorings via SEM nanomanipulation on a silicon substrate.
Efficient plasmon-mediated energy funneling to the surface of Au@Pt core-shell nanocrystals.
Engelbrekt, C., Crampton, K. T., Fishman, D. A., Law, M., Apkarian, V. A. ACS Nano, 14, 5061-5074 (2020) PDF Online Article
Uniform supported metal nanocrystal catalysts prepared by slurry freeze-drying.
Yang, A. Y., Law, M. Chemistry of Materials, 33, 256–265 (2021) PDF Online Article
Reversible aggregation of covalently cross-linked gold nanocrystals by linker oxidation.
Luan, Z., Salk, T., Abelson, A., Jean, S., Law, M. Journal of Physical Chemistry C, 123, 23643-23654 (2019) PDF Online Article
Silica shell growth on vitreophobic gold nanoparticles probed by plasmon resonance dynamics.
Engelbrekt, C., Gargasya, Y., Law, M. J. Phys. Chem. C, 125, 25119–25125 (2021) PDF Online Article