|About this Abstract
||Materials Science & Technology 2019
||Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
||3-D Assembled MnO2 Nanosheets and Conversion to Tunnel-structured MnO2
||Scott Misture, Peter Metz, Madeleine Flint, Robert Koch, Alec Ladonis, Peng Gao
|On-Site Speaker (Planned)
Ceramics with 2-dimensional crystal structures have recently been the topic of intense study for electrochemical charge storage, with many materials amenable to exfoliation to form 2-D nanosheets. 2-D MnO2 nanosheets were prepared via exfoliation of high-perfection starting microcrystalline powders and reassembled into 3-D porous structures. As capacitor electrodes, these materials reach over 350 F/g when we intentionally reduce the nanosheets to form a fixed quantity of trivalent Mn ions. X-ray total scattering was teamed with X-ray spectroscopy, Raman and related tools were used to probe both the mesostructure and the atomic defects of MnO2 nanosheet assemblies perturbed by different aqueous treatments. Heating converts the porous 3-D array of nanosheets into tunnel-structured MnO2, yielding hierarchical porosity; that is, the mesopores remain and new tunnels are created. We further show conversion to Mn2O3 with unique droplet microstructure, also of remarkably high surface area.
||Definite: At-meeting proceedings