Morelos-Gómez A, Vega-Díaz SM, González VJ, Tristán-López F, Cruz-Silva R, Fujisawa K, Muramatsu H, Hayashi T, Mi X, Shi Y, Sakamoto H, Khoerunnisa F, Kaneko K, Sumpter BG, Kim YA, Meunier V, Endo M, Muñoz-Sandoval E, Terrones M. Clean nanotube unzipping by abrupt thermal expansion of molecular nitrogen: graphene nanoribbons with atomically smooth edges.
ACS NANO 2012;
6:2261-2272. [PMID:
22360783 DOI:
10.1021/nn2043252]
[Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report a novel physicochemical route to produce highly crystalline nitrogen-doped graphene nanoribbons. The technique consists of an abrupt N(2) gas expansion within the hollow core of nitrogen-doped multiwalled carbon nanotubes (CN(x)-MWNTs) when exposed to a fast thermal shock. The multiwalled nanotube unzipping mechanism is rationalized using molecular dynamics and density functional theory simulations, which highlight the importance of open-ended nanotubes in promoting the efficient introduction of N(2) molecules by capillary action within tubes and surface defects, thus triggering an efficient and atomically smooth unzipping. The so-produced nanoribbons could be few-layered (from graphene bilayer onward) and could exhibit both crystalline zigzag and armchair edges. In contrast to methods developed previously, our technique presents various advantages: (1) the tubes are not heavily oxidized; (2) the method yields sharp atomic edges within the resulting nanoribbons; (3) the technique could be scaled up for the bulk production of crystalline nanoribbons from available MWNT sources; and (4) this route could eventually be used to unzip other types of carbon nanotubes or intercalated layered materials such as BN, MoS(2), WS(2), etc.
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