THEORY OF NANOSTRUCTURE SYNTHESIS - EXAMPLES OF RECENT ADVANCES: NANOTUBES, GRAPHENE, AND 2D BORON

Recent C&EN cover article offers a retrospect of nanotube research within a framework of Gartner’s hype peak [1], tacitly inviting the readers to gauge the peak phases for graphene or 2D materials "beyond graphene". In such a large timeframe, one ponders why the progress in theory of nanotube synthesis has been so slow, with the origin of helical symmetries, pointed to in 1991 by Iijima, having taken two decades to yield a formula [2] R ~ sin x (growth rate R, helical angle x). Analysis of the interplay between the kinetics and thermodynamics nucleation and growth on solid catalysts reveals sharply peaked abundance distribution A ~ x·exp (-x) [3], and explains the puzzling (n, n-1) types observed in many laboratory syntheses. Building on this approach in case of graphene, a similar combined analysis of the nucleation and growth (implemented with the DFT and Monte Carlo models) explains the low symmetry shapes of islands growing on certain substrates [4]. We will also discuss a non-carbon example of emergent interest, the 2D pure boron, where theoretical analyses of nucleation and growth-type selection (on metal substrates) predict specific structures which now seem to appear in experiments [5].

[1] Davenport, Chemical & Engineering News 2015, 93, 10-15.

[2] Ding et al. PNAS 2009, 106, 2506; R. Rao et al. Nature Mater. 2012, 11, 213.

[3] Artyukhov - Penev et al. Nature Comm. 2014, 5, 489.

[4] Artyukhov et al. PNAS 2012, 109, 15136; Hao et al. Science, 2013, 342, 720; Artyukhov et al. Phys. Rev. Lett. 2015, 114, 115502.

[5] Liu et al. Angewandte Chemie 2013, 52, 3156; Zhang et al. Angewandte Chemie 2015, 54, 13022.