Alan Dai

All Publications

• Nanoscale and ultrafast <i>in situ</i> techniques to probe plasmon photocatalysis CHEMICAL PHYSICS REVIEWS Carlin, C. C., Dai, A. X., Al-Zubeidi, A., Simmerman, E. M., Oh, H., Gross, N., Lee, S. A., Link, S., Landes, C. F., da Jornada, F. H., Dionne, J. A. 2023; 4 (4)

  View details for DOI 10.1063/5.0163354

  View details for Web of Science ID 001112242700001

• Linking Atomic and Reactor Scale Plasmon Photocatalysis in Acetylene Hydrogenation with Optically Coupled ETEM. Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada Bourgeois, B., Carlin, C., Angell, D., Swearer, D., Cheng, W. H., Dai, A., Yuan, L., Dionne, J. 2023; 29 (Supplement_1): 1298-1299

  View details for DOI 10.1093/micmic/ozad067.664

  View details for PubMedID 37613409

• LiH formation and its impact on Li batteries revealed by cryogenic electron microscopy. Science advances Vilá, R. A., Boyle, D. T., Dai, A., Zhang, W., Sayavong, P., Ye, Y., Yang, Y., Dionne, J. A., Cui, Y. 2023; 9 (12): eadf3609

  Abstract

  Little is known about how evolved hydrogen affects the cycling of Li batteries. Hypotheses include the formation of LiH in the solid-electrolyte interphase (SEI) and dendritic growth of LiH. Here, we discover that LiH formation in Li batteries likely follows a different pathway: Hydrogen evolved during cycling reacts to nucleate and grow LiH within already deposited Li metal, consuming active Li. We provide the evidence that LiH formed in Li batteries electrically isolates active Li from the current collector that degrades battery capacity. We detect the coexistence of Li metal and LiH also on graphite and silicon anodes, showing that LiH forms in most Li battery anode chemistries. Last, we find that LiH has its own SEI layer that is chemically and structurally distinct from the SEI on Li metal. Our results highlight the formation mechanism and chemical origins of LiH, providing critical insight into how to prevent its formation.

  View details for DOI 10.1126/sciadv.adf3609

  View details for PubMedID 36961896

• Driving energetically unfavorable dehydrogenation dynamics with plasmonics. Science (New York, N.Y.) Sytwu, K. n., Vadai, M. n., Hayee, F. n., Angell, D. K., Dai, A. n., Dixon, J. n., Dionne, J. A. 2021; 371 (6526): 280–83

  Abstract

  Nanoparticle surface structure and geometry generally dictate where chemical transformations occur, with higher chemical activity at sites with lower activation energies. Here, we show how optical excitation of plasmons enables spatially modified phase transformations, activating otherwise energetically unfavorable sites. We have designed a crossed-bar Au-PdH x antenna-reactor system that localizes electromagnetic enhancement away from the innately reactive PdH x nanorod tips. Using optically coupled in situ environmental transmission electron microscopy, we track the dehydrogenation of individual antenna-reactor pairs with varying optical illumination intensity, wavelength, and hydrogen pressure. Our in situ experiments show that plasmons enable new catalytic sites, including dehydrogenation at the nanorod faces. Molecular dynamics simulations confirm that these new nucleation sites are energetically unfavorable in equilibrium and only accessible through tailored plasmonic excitation.

  View details for DOI 10.1126/science.abd2847

  View details for PubMedID 33446555

• Unraveling the origin of chirality from plasmonic nanoparticle-protein complexes. Science (New York, N.Y.) Zhang, Q. n., Hernandez, T. n., Smith, K. W., Hosseini Jebeli, S. A., Dai, A. X., Warning, L. n., Baiyasi, R. n., McCarthy, L. A., Guo, H. n., Chen, D. H., Dionne, J. A., Landes, C. F., Link, S. n. 2019; 365 (6460): 1475–78

  Abstract

  Plasmon-coupled circular dichroism has emerged as a promising approach for ultrasensitive detection of biomolecular conformations through coupling between molecular chirality and surface plasmons. Chiral nanoparticle assemblies without chiral molecules present also have large optical activities. We apply single-particle circular differential scattering spectroscopy coupled with electron imaging and simulations to identify both structural chirality of plasmonic aggregates and plasmon-coupled circular dichroism induced by chiral proteins. We establish that both chiral aggregates and just a few proteins in interparticle gaps of achiral assemblies are responsible for the ensemble signal, but single nanoparticles do not contribute. We furthermore find that the protein plays two roles: It transfers chirality to both chiral and achiral plasmonic substrates, and it is also responsible for the chiral three-dimensional assembly of nanorods. Understanding these underlying factors paves the way toward sensing the chirality of single biomolecules.

  View details for DOI 10.1126/science.aax5415

  View details for PubMedID 31604278

• Highly tunable platform for biomimetic catalysts from nanocrystal-polymer composites Riscoe, A., Wrasman, C., Menon, A., Hilbert, M., Dai, A., Vargas, M., Goodman, E., Yang, A., Beck, A., Wu, L., Cargnello, M. AMER CHEMICAL SOC. 2018

  View details for Web of Science ID 000435537706226