Plasmon-mediated Photochemical and Photophysical Processes
Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
Final Report Abstract
My time at Rice as a DFG postdoctoral research fellow resulted in a fruitful completion of my specific aims that are reflected in three peer-reviewed publications. I successfully developed a methodology that allows the simultaneous detection of many individual nanoparticles while rendering high-quality wavelength spectra characterized by a short acquisition time of the detector, a high spectral resolution, and a great signal to noise ratio. My experimental method presents an important step toward understanding the effect of particle polydispersity and light on fast, irreversible plasmon-mediated processes via spectroscopic imaging. In detail, I accomplished a novel approach, termed ‘snapshot hyperspectral imaging’ that provides an in situ spectroscopic mapping of ≥ 100 individual nanostructures in a fast and truly parallel manner. It renders discernable signals on the 1 ms time scale with a spectral resolution of 0.21 nm/pxl and signal to noise ratios of S/N = 125. This combination of particle number, integration time, and spectral resolution is pivotal and has not been achieved before. Employing the novel snapshot hyperspectral imaging methodology, I investigated the heterogeneous and fast kinetics of Au oxide formation in an electrochemical cell. In the second part of my fellowship, I closely investigated plasmon-mediated cathodic currents in Au/TiO2 composite photoelectrodes to pave way for understanding and realizing selective solar-to-fuel conversion. My novel approach to tandem tunable electric interfaces with enhanced chemical absorption of CO2 molecules in a plasmonic photoelectrode tackled the scientific challenges of selective and efficient CO2-to-fuel conversion and led to a successful user proposal between the Lawrence Berkeley National Lab and Caltech.
Publications
- (2018) Plasmonic Sensing and Control of Single-Nanoparticle Electrochemistry. Chem 4 (7) 1560–1585
Hoener, Benjamin S.; Kirchner, Silke R.; Heiderscheit, Thomas S.; Collins, Sean S.E.; Chang, Wei-Shun; Link, Stephan; Landes, Christy F.
(See online at https://doi.org/10.1016/j.chempr.2018.04.009) - Spectral Response of Plasmonic Gold Nanoparticles to Capacitive Charging: Morphology Effects. The Journal of Physical Chemistry Letters 2017, 8 (12), 2681-2688
Hoener, B. S.; Zhang, H.; Heiderscheit, T. S.; Kirchner, S. R.; De Silva Indrasekara, A. S.; Baiyasi, R.; Cai, Y.; Nordlander, P.; Link, S.; Landes, C. F.
(See online at https://doi.org/10.1021/acs.jpclett.7b00945) - Snapshot Hyperspectral Imaging (SHI) for Revealing Irreversible and Heterogeneous Plasmonic Processes. The Journal of Physical Chemistry C 2018, 122 (12), 6865-6875
Kirchner, S. R.; Smith, K. W.; Hoener, B. S.; Collins, S. S.; Wang, W.; Cai, Y.-Y.; Kinnear, C.; Zhang, H.; Chang, W.-S.; Mulvaney, P.
(See online at https://doi.org/10.1021/acs.jpcc.8b01398)
