Nanoscale Chemical Imaging and Spectroscopy of Energy Nanomaterials by Scanning Transmission X-ray Microscopy

J. Wang, J. Zhou
Canadian Light Source Inc., CA

Keywords: STXM, chemical imaging, nanospectroscopy, energy nanomaterials

Summary:

Carbon nanotube (CNT) and graphene, and their nanocomposites have been showing great promise in energy related applications owing to their unique structure and extraordinary properties. Along the materials development and performance enhancement, advancing our understanding and knowledge on these novel carbon nanomaterials at the nanoscale is critical. A complete and in-depth characterization requires microscopic measurements with both high spatial resolution and high chemical sensitivity. Synchrotron based scanning transmission X-ray microscopy (STXM) using a nanoscaled focused soft X-ray beam (~30 nm) provides an excellent combination of microscopic examination and chemical/electronic structure speciation via XANES spectroscopy for individual nanomaterials particles. For the past few years we have systematically investigated a large number of CNT and graphene based nanomaterials, including electronic structure and chemical imaging of individual CNT and graphene, and surface interaction/bonding and chemical mapping of CNT/graphene supported catalysts, sensor materials, LIB electrode mateirals, and hydrogen storage materials. Our findings not only disclosed the morphological, compositional and electronic structure variations, but also revealed the chemical interactions/bonding, defects and contaminants associated with individual carbon nanomaterials. In this presentation, selected examples will be presented to demonstrate the capabilities of STXM in these applications.