Hydrogen physisorption energies for bumpy, saturated, nitrogen-doped single-walled carbon nanotubes

We describe a general, symmetry-conditioned way of enumerating isomers of saturated singly substituted one-dimensional nanothreads of the (CH)E and (CH)CR type, where E is a heteroatom and R is a substituent. Four nanothreads - so-called tube (3,0), polytwistane, the zipper polymer, and polymer I, are treated in detail. The methodology, combining symmetry arguments and computer-based enumeration, is generally applicable to isomerism problems in polymers.

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“…We direct the reader also to several papers on nitrogen-containing saturated threads. Please see refs , , and .…”

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confidence: 99%

All the Ways To Have Substituted Nanothreads

Chen

Wang

Crespi³

et al. 2018

J. Chem. Theory Comput.

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“…For example, doping with nitrogen decreases the toxicity of nanotubes [10] and gives them excellent catalytic properties in oxygen reduction reactions [11,12]. The bumpy nanotubes present interesting values of hydrogen physisorption energies (0.26 eV/H 2 ), better than similar regular nanotubes, estimated through theoretical studies based on the density functional theory (DFT) [13]. This physisorption energy value is within the suggested ideal range for using hydrogen as a clean energy media [14].…”

Section: Introductionmentioning

confidence: 82%

Carbon Nanotubes: Molecular and Electronic Properties of Regular and Defective Structures

Fuentes¹,

Soto²

2018

Density Functional Calculations - Recent Progresses of Theory and Application

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In this chapter, we describe how structural parameters affect the reactivity of singlewalled carbon nanotubes through global reactivity descriptors obtained by the DFT methods (B3LYP/6-31G(d) with real frequencies in all cases). First, we investigate regular armchair, chiral, and zigzag nanotubes with bumpy defects (five-and sevenmembered rings), finding that regular and defective zigzag nanotubes exhibit the greater conductive ability, reactivity, and capacity of nanotubes to be reduced. The bumpy defects favor those properties with greater intensity in chiral nanotubes. We also investigate how the properties of armchair nanotubes change in the presence of bumpy, haeckelite, Stone-Wales, and zipper defects, and we found that armchair nanotubes with zipper defects show greater reactivity and better conducting abilities enhanced by nitrogen doping and longer nanotubes. In addition, for armchair nanotubes containing bumpy defects, our results reveal, considering B3LYP-D3 correction, that bumpy defects confer a greater ability to physically adsorb hydrogen, with adsorption energies of 0.32 eV/adsorbed H 2. That value is considered ideal for the reversible adsorption of hydrogen at room temperature and low pressures and therefore favorable for use as a clean energy source. These results contribute to the future design of novel useful materials based in carbon nanotubes.

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