Energy-driven surface evolution in beta-MnO < inf> 2 structures
Document Type
Article
Publication Date
6-8-2017
Department
Department of Mechanical Engineering-Engineering Mechanics
Abstract
Exposed crystal facets directly affect the electrochemical/catalytic performance of MnO2 materials during their applications in supercapacitors, rechargeable batteries, and fuel cells. Currently, the facet-controlled synthesis of MnO2 is facing serious challenges due to the lack of an in-depth understanding of their surface evolution mechanisms. Here, combining aberration-corrected scanning transmission electron microscopy (STEM) and high-resolution TEM, we revealed a mutual energy-driven mechanism between beta-MnO2 nanowires and microstructures that dominated the evolution of the lateral facets in both structures. The evolution of the lateral surfaces followed the elimination of the {100} facets and increased the occupancy of {110} facets with the increase in hydrothermal retention time. Both self-growth and oriented attachment along their {100} facets were observed as two different ways to reduce the surface energies of the beta-MnO2 structures. High-density screw dislocations with the 1/2 < 100> Burgers vector were generated consequently. The observed surface evolution phenomenon offers guidance for the facet-controlled growth of beta-MnO2 materials with high performances for its application in metal-air batteries, fuel cells, supercapacitors, etc.
Publication Title
Nano Research
Recommended Citation
Yao, W.,
Yuan, Y.,
Asayesh Ardakani, H.,
Huang, Z.,
Long, F.,
Friedrich, C.,
Amine, K.,
Lu, J.,
&
Shahbazian-Yassar, R.
(2017).
Energy-driven surface evolution in beta-MnO < inf> 2 structures.
Nano Research,
11(1), 206-215.
http://doi.org/10.1007/s12274-017-1620-5
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/5131