Stabilities and electronic properties of nanowires made of single atomic sulfur chains encapsulated in zigzag carbon nanotubes

Abstract

Theoretical investigations are carried out on the recently synthesized one-dimensional nanowires made of atomic sulfur chains encapsulated in carbon nanotubes (called S@CNTs). Special attention is paid to stability, electronic property and transport properties of these combined nanowires. It is found that the encapsulation is exothermic when S@CNTs are built from the tubes with diameter larger than 6.4 Å. Thus the experimental results are energetically favorable since the diameters of the CNTs are about 6 Å in the obtained S@CNTs. The combined nanowires can be stabilized by van der Waals interaction between sulfur chain and tube as indicated from radial distribution function and reduced density gradient descriptions. All S@CNTs studied in this work exhibit metallic property with the partially filled bands. However, the conducting component and the pathway of charge carriers are various. For instance, only the sulfur chain is the conducting pathway for S@CNT(8, 0), while both the sulfur chain and tube are the conducting pathways for S@CNT(9, 0). This interesting feature was understood based on the band structures and crystal orbital analysis. The electronic transport properties of the systems are performed by investigating and analyzing the transmission spectra, current-voltage (I-V) curves and transmission eigenstate, which confirm that the sulfur chains can improve the electronic transport of CNTs. Moreover, the electrostatic interaction resulted from the charge transfer between the two components of S@CNTs should be favorable to the stability of the combined nanowires.

Interaction in Li@Fullerenes and Li+@Fullerenes: First Principle Insights to Li-Based Endohedral Fullerenes

“…Furthermore, the intensity of dispersion interaction increased quickly as we examined increasingly large cages, due to the greater negative values for E dis . It is well-known that the dispersion interactions are among the important non-covalent interactions for many host-guest systems [44,45,46,47,48]. However, the values we calculated E dis are within 8 kcal for both Li@C n and Li + @C n in this work.…”

“…In order to directly depict the physical image of the interaction between carbon cages and the hosted Li and Li + , here non-covalent interaction analysis is discussed based on the reduced density gradient (RDG). It is well known that RDG has become an effective tool to reveal the non-covalent interaction of various host-guest systems [44,45,46,47,48]. The visualizations of RDG for Li@C n and Li + @C n with n = 20, 24, 44, 48, 50 and 70 are shown in Figure 4.…”

Nitrogen and Oxygen Codoped Porous Carbon with Superior CO2 Adsorption Performance: A Combined Experimental and DFT Calculation Study

“…31 Similar theoretical calculations involving noncovalent interactions were reported in previous literature. 16,32,33 All calculations were performed using the SCF-MO method, and the results were obtained by using the M06-2X functional combined with 6-31G (d, p) basis sets. All theoretical cluster models were established according to the XPS characterization data.…”

Encapsulation and Adsorption of Halogens into Single-Walled Carbon Nanotubes

“…A variety of atoms [13,14], molecules [15,16], one-dimensional nanocrystals [17][18][19][20][21], nanowires [22,23], and nanoribbons [24,25] have been encapsulated experimentally inside the SWNTs. The filling of bulk material has led to the formation of the one-dimensional nanocrystal, which is different from the bulk structure [26,27].…”