About the event
Speaker: Prof. Liane Moreau, Assistant Professor, WSU Department of Chemistry
Title: Towards bottom-up engineering of doped and anisotropic nanostructures: pairing synthetic inorganic chemistry with advanced x-ray characterization
Abstract: Nanostructures have contributed considerable advances in fields ranging from microelectronics to energy and medicine due to the emergent properties arising from the appearance of quantization effects. Although the synthesis of nanostructures in most parts of the periodic table have been empirically well-developed, the mechanisms behind achieving precise control over particle size, atomic distribution and morphology remain largely elusive. Additionally, little work exists either synthetically or mechanistically regarding the formation of actinide nanostructures. The aforementioned areas of needed exploration are challenging in that nanostructures (particularly with sizes below 10 nm) are inherently difficult to fully characterize on the atomic scale due to broadening which occurs in diffraction-based characterization methods and the high concentration of surface defects and energy-minimization effects. To address these challenges, x-ray spectroscopic and scattering based methods are used to probe challenging nanoscale systems in detail over multiple-length scales. In particular, synthetic developments are paired with robust characterization, in order to improve knowledge of how nanostructure processing correlates with resulting structural and electronic attributes.
Two key thrusts will be highlighted: 1) interrogating how two disparate atomic species will interact on the nanoscale (e.g., a primary structure being doped with a secondary species) and 2) determining the factors which govern nanostructure anisotropic growth. Related to the first thrust, the use of kinetics to control atomic distributions in bimetallic nanoparticles will be discussed along with the effects of lanthanide dopants in nano CeO2 on electronic structure attributes. Additionally, the interaction between UO22+ and iron interfaces will be explored. Regarding thrust two, anisotropic growth in both gold and UO2 nanostructures by seed-mediated synthesis will be compared, and a method to differentiate chemistry at a nanoparticle surface from chemistry within the particle interior will be described. Overall, each of the systems herein considers the systematic connection between synthetic processes employed and the structure of the resulting constructs from the atom through nanometer length scales. It is only through comprehensive characterization, including use of advanced x-ray techniques, that this can be accomplished.