Featured Research Highlights
Precisely Sized Channels in Novel Electrodes Enable Electrochemical Water Desalination
Scientific Achievement In electrochemical water desalination (or hybrid capacitative deionization), positive ions intercalate into the structure of the NWs, where they are trapped within precisely shaped/sized channels. An example of alpha-...
Deactivation Mechanism in NOx Reduction Zeolite Catalysts Revealed by Atom Probe Tomography
Scientific Achievement Reconstructed APT results (Cu-Al atom maps) for aged Cu-ZSM-5 (left) and Cu-SSZ-13 (right). Extensive Cu-Al affinity observed in Cu-ZSM-5 after aging, consistent with the formation of CuAl2O4 phase leading to rapid...
Z-contrast Scanning Transmission Electron Microscopy performed at CNMS shows the “tunnel” (or “channel”) structure in stable MnO2 nanowires, which have precisely tuned sizes that give them selectivity to particular ions in brackish water.
B. W. Byles, D. A. Cullen, K. L. More, and E. Pomerantseva, "Tunnel structured manganese oxide nanowires as redox active electrodes for hybrid capacitive deionization," Nano Energy 44, 476-488 (2018). DOI: 10.1016/j.nanoen.2017.12.015
Helium ion microscopy is shown to be a highly promising method to quickly determine porosity on commercial SiO2 samples commonly used for catalysis, outperforming SEM by overcoming charging effects (or requirement of sample pretreatment) and providing higher resolution as well as providing much faster and more detailed information than gas absorption methods.
M. J. Burch, A. V. Ievlev, K. Mahady, H. Hysmith, P. D. Rack, A. Belianinov, and O. S. Ovchinnikova, "Helium ion microscopy for imaging and quantifying porosity at the nanoscale," Anal. Chem. 90, 1370-1375 (2018). DOI: 10.1021/acs.analchem.7b04418
Atom-level deactivation processes in industrial zeolite catalysts are revealed in atom probe tomography (APT), which yields the first direct observations of chemical distributions.
J. E. Schmidt, R. Oord, W. Guo, J. D. Poplawsky, B. M. Weckhuysen, "Nanoscale tomography reveals the deactivation of automotive copper-exchanged zeolite catalysts," Nature Communications 8, 1666 (2017). DOI: 10.1038/s41467-017-01765-0
A combination of coupled first-principles calculations and database searches led to a discovery of electrides having 1D building blocks that accommodate topologically protected metallic states.
C. Park, S. W. Kim, and M. Yoon, "First-principles prediction of new electrides with nontrivial band topology based on one-dimensional building blocks," Phys. Rev. Lett. 120 (2), 026401 (2018).
Using in-situ electrochemical atomic force microscopy, electrochemically induced surface reactions are observed at an electrolyte-anode interface, as needed for the advancement of iron-air batteries.
H. Weinrich, J. Come, H.Tempel, H. Kungl, R.-A.Eichel, N. Balke, "Understanding the nanoscale redox-behavior of iron-anodes for rechargeable iron-air batteries," Nano Energy 41, 706 (2017). DOI: 10.1016/j.nanoen.2017.10.023
Helium ions are used to fabricate highly pure platinum structures in liquid, with sizes to below 15-nanometers – smaller than by other direct-write technique.
A. V. Levlev, J. Jakowski, M. J. Burch, V. Iberi, H. Hysmith, D. C. Joy, B. G. Sumpter, A. Belianinov, R. R. Unocic, and O.S . Ovchinnikova, "Building with ions: towards direct write of platinum nanostructures using in situ liquid cell helium ion microscopy," Nanoscale 9, 12949 (2017). DOI: 10.1039/C7NR04417H
A model forms a “road map” for using low-frequency Raman signatures to efficiently determine properties of stacked 2D materials.
L. Liang, A. A. Puretzky, B. G. Sumpter, V. Meunier, Nanoscale, accepted for publication (2017). DOI: 10.1039/C7NR05839J
Four probe scanning tunneling microscopy, simultaneously using ferromagnetic and nonmagnetic probes, effectively forms a “spin voltmeter.”
S. M. Hus, X.-G. Zhang, G. D. Nguyen, W. Ko, A. P. Baddorf, Y. P. Chen, A.-P. Li. Phys. Rev. Lett., 119, 137202 (2017). DOI: 10.1103/PhyRevLett.119.137202
A correction that considers artificial density differences in Atom Probe Tomography data is developed; this leads to the ability to determine interfacial widths with 1 Å precision.
O. Dyck, D.N. Leonard, L.F. Edge, C.A. Jackson, E.J. Pritchett, P.W. Deelman, and J.D. Poplawsky, Adv. Mater. Interfaces, accepted for publication and available as “early view” paper (2017). DOI: 10.1002/admi.201700622