Periodic DFT and HR-STEM Studies of Surface Structure and Morphology of Cobalt Spinel Nanocrystals. Retrieving 3D Shapes from 2D Images

Filip Zasada , Witold Piskorz , Paweł Stelmachowski , Andrzej Kotarba , Jean-François Paul , Tomasz Płociński , Krzysztof Kurzydłowski , Zbigniew Sojka


In this study, we investigated the morphology of Co3O4 nanocrystals using periodic PW91 and PW91+U density functional calculations and Wulff construction. Theoretical investigations were combined with high resolution scanning transmission electron microscopy, which revealed that the examined spinel samples, obtained by pH-controlled precipitation, exhibit well-developed faceted crystallites. The results of slab calculations enabled to characterize the surface structure and reconstruction of the low index (100), (110), and (111) planes that were observed in HR-STEM pictures. The surface energies of the relaxed facets increased in the following order 1.39 J m?2 (100) \\textless\ 1. 48 J m?2 (111) \\textless\ 1.65 J m?2 (110). These ab initio calculated values were used to predict a rhombicuboctaedral equilibrium habit of the cobalt spinel crystallites, by means of the Wulff plot. The obtained results were in remarkable agreement with the experimental shapes retrieved by matching 3D Wulff polyhedra to 2D STEM images observed along three different [100], [110], and [111] directions. Thus, the joined theoretical and experimental approach applied successfully herein, allowed not only for univocal shape determination and surface structure reconstruction of the faceted Co3O4 nanocrystals, but also provided the in-depth understanding of the observed features at the atomic level.
Author Filip Zasada
Filip Zasada,,
, Witold Piskorz
Witold Piskorz,,
, Paweł Stelmachowski
Paweł Stelmachowski,,
, Andrzej Kotarba
Andrzej Kotarba,,
, Jean-François Paul
Jean-François Paul,,
, Tomasz Płociński ZPM
Tomasz Płociński,,
- Division of Materials Design
, Krzysztof Kurzydłowski ZPM
Krzysztof Kurzydłowski,,
- Division of Materials Design
, Zbigniew Sojka
Zbigniew Sojka,,
Journal seriesJournal of Physical Chemistry C, ISSN 1932-7447
Issue year2011
Publication size in sheets0.5
Languageen angielski
Score (nominal)35
Publication indicators WoS Impact Factor: 2011 = 4.805 (2) - 2011=5.049 (5)
Citation count*37 (2018-02-19)
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* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.