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![HAADF-STEM image of a WS2 nanotube taken in a probe-side corrected FEI Titan 80-300 microscope operated at 300 kV. The projected potential of a four-shell tube is overlaid [roll-up vectors and chiral angles (4,92, 2.1°) (6,103, 2.8°) (5,115, 2.1°) (7,123, 2.7°)]. The correspondence between the two in the atomic scale is apparent and the helicity can be clearly seen.](profile/Andrey-Enyashin/publication/23303137/figure/fig4/AS:601708610736128@1520469920008/HAADF-STEM-image-of-a-WS2-nanotube-taken-in-a-probe-side-corrected-FEI-Titan-80-300.png)
HAADF-STEM image of a WS2 nanotube taken in a probe-side corrected FEI Titan 80-300 microscope operated at 300 kV. The projected potential of a four-shell tube is overlaid [roll-up vectors and chiral angles (4,92, 2.1°) (6,103, 2.8°) (5,115, 2.1°) (7,123, 2.7°)]. The correspondence between the two in the atomic scale is apparent and the helicity can be clearly seen.
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The characterization of nanostructures down to the atomic scale is essential to understand some physical properties. Such a characterization is possible today using direct imaging methods such as aberration-corrected high-resolution transmission electron microscopy (HRTEM), when iteratively backed by advanced modeling produced by theoretical struct...
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... lines because of the large roll-up vectors of the WS 2 nanotubes. Therefore, fine details in the principal lines of the diffraction pattern could be hidden, which would make the iden- tification of nonchiral shells complicated. Nonetheless, real-space images can be used to gather more information by examining individual nanotubes of interest. Fig. 7 shows the high-angle annular dark-field (HAADF) STEM image of the atypical case of a tube with all shells being chiral. The aberration-corrected HAADF STEM was used because of the close relation between the images produced and the projected potential of the structures. In these images, the signal of a single atom is strongly dependent ...
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... and the projected potential of the structures. In these images, the signal of a single atom is strongly dependent on the atomic number Z. The sensitivity to the light elements is lost, in this case with the advantage that the W sublattice is revealed more clearly and directly. The depth of field is strongly limited in HAADF, so that the image in Fig. 7 illustrates just the upper part of the tube. All shells in the tube seem to be helical, with a similar chiral angle that can be retrieved from the FFT using the same procedure described before. The adjacent shells cannot be of exactly the same chiral angle, because this would produce shells with varying distances, some of them much ...
Citations
... In particular, essential morphologies for various applications are hollow WS2 structures, nanotubes (NTs) [8][9][10], and fullerenes [11][12][13], discovered by Tenne in 1992 [14]. Since then, deep insight was gained into the mechanism of the sulfidation reaction [9,11,15], the structure of the products [16], physical [17], optical [18,19], and chemical characteristics [20,21]. Various synthetic strategies were devised to prepare hollow WS2 structures [22,23] and industrial production [24], and broad applications of these materials were eventually introduced. ...
... An article by Yomogida et al. [19] presents images of three-and five-walled NTs obtained using transmission electron microscopy. Earlier publications [20][21][22] report a similar study of four-and five-walled WS 2 NTs. Both "armchair" and "zigzag" achiral nanotubes [20,23] and chiral tubular nanostructures [21,22] have been described. ...
... Earlier publications [20][21][22] report a similar study of four-and five-walled WS 2 NTs. Both "armchair" and "zigzag" achiral nanotubes [20,23] and chiral tubular nanostructures [21,22] have been described. ...
... It has been shown that the electronic structure, mechanical and optical properties of multi-walled WS 2 NTs depend on such structural parameters as the diameter and number of walls [8,24,25]. In the study of nanotubes of metal chalcogenides, various methods of structure modeling were used [20,25]. Nevertheless, the most accurate modeling technique, quantum mechanical calculations, is applicable only to fairly thin and maximally triple-walled nanotubes [26][27][28][29][30][31][32][33][34][35]. ...
... In particular, essential morphologies for various applications are hollow WS2 structures, nanotubes (NTs) [8][9][10], and fullerenes [11][12][13], discovered by Tenne in 1992 [14]. Since then, deep insight was gained into the mechanism of the sulfidation reaction [9,11,15], the structure of the products [16], physical [17], optical [18,19], and chemical characteristics [20,21]. To prepare hollow WS2 structures, various synthetic strategies were devised [22,23], and eventually, industrial production [24] and broad applications of these materials were introduced. ...
Our work describes the nanofibrous materials of tungsten disulfide, which can be tuned by the precursor's crystallinity degree. The carefully formulated nanofibers create the morphological crossroad between fullerenes (0D), nanotubes (1D), plates (2D), and a nonwoven web of nanofibers (3D), containing all the advantageous properties of the presented material categories. Our synthetic methodology (electrospinning, reductive sulfidation) allows scale-up to industrial production. In addition, we studied the optical properties of the WS2 nanofibers using extinction and absolute absorption measurement. The results of the optical analysis further indicate the higher crystallinity of the closed stacked fullerene-based structure. By comparison of the extinction with the absorbance, we find that all the examined nanostructures display typical polaritonic spectra. However, the open plate structure exhibits a stronger scattering and thus better pronounced polaritonic features. Moreover, the ability to control the morphology allows for variating polaritonic features of the final nanofibrous material, which can directly impact the potential optoelectronic and photocatalytic applications.
... In other words, measurable patterns of longer period are caused by an interaction of similar periodic structures of shorter periods. The moire´effect [1][2][3] is not unknown in the metrology, 4-6 optical measurements, [7][8][9] nanoparticles, 10,11 and other areas of scientific research. In particular, the books 2,6 provide the theoretical foundation, Refs. ...
... In particular, the books 2,6 provide the theoretical foundation, Refs. 1,4,5,[7][8][9] describe the useful usage of the moire´patterns in practical measurements, Saveljev et al. 3 describes a special type of displays (the reduction of moire´and the visual display including 3D case), and Bassett et al. 10 and Sadan et al. 11 show the moire´effect in nanoparticles. ...
We measured vertical and horizontal displacements of distant objects based on the moiré effect. The grid attached to the object was photographed and recorded on video camera. The video was processed later in the lab. The method is self-calibrated and does not need special equipment in the field (except for a regular videographer’s apparatus). The objectives of this study were to create a method for non-contact moiré measurement based on camera images and to find a way to deal with anomalous vibrations of structures. The experimental measurements of the fundamental frequency are in accordance with the theory of square beams. Tests with broken models were also conducted. The influence of two opposite factors on the fundamental frequency in the beams with cracks was estimated. In determining the pre-failure condition, the decay rate seems to be a more promising indicator than the fundamental frequency; however, this was only observed when a crack was near the fixed edge. The results and findings can be applied in measuring displacement in various objects; in public safety, and particularly, in distinguishing between normal and abnormal vibration in bridges.
... Another important virtue of inorganic layered compounds is that they can form hollow closed nanostructures in 1D (INT) or 0D (IF) (Fig. 3) [6][7][8]50]. From physicochemical principles, the notion of hollow closed nanostructures is not trivial at all. First, hollow core of mesoscopic dimensions (> 1 nm) is not favorable from the thermodynamic standpoint. ...
... A simulated best fit is enclosed by the white box. (d) Calculated electrostatic potential image of a WS 2 nanooctahedra (the smallest IF available) (redrawn from Ref.[50]. ...
The birth of nanoscience more than 50 years ago fueled the renaissance in layered materials research leading to many materials discoveries with unprecedented scientific and technological impacts. Following the early reports on carbon fullerenes and nanotubes, the discovery of inorganic one-dimensional (1D) nanotubes and zero-dimensional (0D) fullerenes created a major playground for new physicochemical observations. The meteoric rise of two-dimensional (2D) materials in concert set off outstanding advances in the synthesis and manipulation of layered materials with atomic precision. This review identifies new directions in materials science that emerge through integrating the two layered systems—2D with inorganic 1D and 0D. Summarizing the key developments in the two distinct nanomaterials families, we highlight preliminary instances of integrating them into functional nanostructures. A few gedankenexperiments regarding prospective applications of the integrated system are then introduced to stimulate further experimental and theoretical investigations that can potentially result in unforeseen scientific observations.Graphical abstract
... In search of new materials that can achieve similar applications, the so-called inorganic nanotubes (Serra et al., 2019) have emerged as a viable alternative for replacing carbon nanotubes, since most of the electronic properties are independent of their chirality (Sadan et al., 2008). Among the inorganic nanotubes that have wide application in different areas, we can cite boron nitride nanotubes (BNNT) (dos Golberg et al., 2007;Solimannejad & Noormohammadbeigi, 2017), zirconium oxide nanotubes (ZNT) (Antônio Pinheiro Lobo et al., 2020;Berger et al., 2008), titanium oxide nanotubes (TiO 2 NT) (Jitianu et al., 2004), as well as structures composed of atoms belonging to the same carbon group, such as germanium nanotubes (GeNT's) (Seifert et al., 2001) and silicon nanotubes (SiNTs) (Fagan et al., 2000). ...
In this work, computational chemistry methods were used to study a silicon nanotube (Si192H16) as possible virucidal activity against SARS-CoV-2. This virus is responsible for the COVID-19 disease. DFT calculations showed that the structural parameters of the Si192H16 nanotube are in agreement with the theoretical/experimental parameters reported in the literature. The low energy gap value (0.29 eV) shows that this nanotube is a semiconductor and exhibits high reactivity. For nanomaterials to be used as virucides, they need to have high reactivity and high inhibition constant values. Therefore, the adsorption of ³O2 and H2O on the surface of Si192H16 (Si192H16@O2-H2O) was performed. In this process, the formation and activation energies were −51.63 and 16.62 kcal/mol, respectively. Molecular docking calculations showed that the Si192H16 and Si192H16@O2H-OH nanotubes bind favorably on the receptor-binding domain of the SARS-CoV-2 spike protein with binding energy of −11.83 (Ki = 2.13 nM) and −11.13 (Ki = 6.99 nM) kcal/mol, respectively. Overall, the results obtained herein indicate that the Si192H16 nanotube is a potential candidate to be used against COVID-19 from reactivity process and/or steric impediment in the S-protein.
Communicated by Ramaswamy H. Sarma
... This flexibility is because of its 2D nature, which is analogous to the graphene (Matte et al., 2010). Numerous approaches have been made to produce MoS 2, such as the hydrothermal method (Chang and Chen, 2011b), thermal evaporation-exfoliation (Balendhran et al., 2012), physical vapor deposition (Lee et al., 2012), chemical vapor deposition (Shaw et al., 2014), chemical exfoliation (Sadan et al., 2008), mechanical exfoliation (Zhou et al., 2011), and wet chemical approaches (Altavilla et al., 2011). However, during the synthesis process, these methods led to the formation of buckyball-like nanoparticles or nanotube of MoS 2 (Rosentsveig et al., 2001;Rapoport et al., 2005). ...
Energy storage devices are the ultimate flexible solution to overcome energy deficiency. Thre is a need is to find innovative nanomaterials to overcome the delays in efficiency and sustainability. Herein, we report the synthesis of hierarchical MoS 2 /rGO nanohybrids as electrode material for supercapacitors. Pure phase and flower-shaped molybdenum disulfide (MoS 2) nanosheets have been synthesized using a meek hydrothermal method followed by the preparation of MoS 2 /rGO nanohybrids. The physicochemical aspects and electrochemical properties have been carefully analyzed using cyclic voltammetry and galvanostatic charge-discharge method in the 1 M KCL electrolyte. The capacitance of MoS 2 and MoS 2 /rGO were found to be 297 F/g (66 mAh/g or 238 C/g) and 850 F/g (153.5 mAh/g or 552.5 C/g) at 1 A/g respectively, with 95.3% retention in capacitance after 10,000 cycles at 2 A/g. The improved electrochemical performance of the MoS 2 /rGO electrode could be ascribed to rapid diffusion pathways delivered by rGO and improved redox reactions of hierarchical MoS 2 nanosheets owing to the high surface area (391 m 2 /g). This feature enables a decrease in the entire impedance of electrodes which agrees with the findings obtained from electrochemical impedance spectroscopy.
... [6][7][8] Alternatively, curved TMD nanostructures, such as inorganic fullerenes and nanotubes, naturally possess intriguing structural features and defects, including a range of chiralities, variable registry of concentric shells, size-dependent phase changes, and unusual nanotube capping modalities. [9][10][11][12] Revealing these unique structural features and their impact on material properties, such as mechanical behavior, has enabled the application of inorganic nanostructures in high-strength nanocomposites and solid-state lubrication. 12,13 Comprehensive structural characterization of such complex architectures, particularly via transmission electron microscopy (TEM) and scanning TEM (STEM), is a prerequisite to controllable design of TMD structure and, ultimately, sophisticated property manipulation and defect engineering. ...
Curvature presents a powerful approach to design atomic structure and tailor material properties in atomically thin transition metal dichalcogenides (TMDs). The emerging TMD core-shell architecture, in which a multilayer TMD shell encapsulates a curved nanoparticle core, presents the opportunity to controllably induce defects into a TMD crystal by strategically constructing the shape of the underlying core. However, harnessing this potential platform first requires robust characterization of the unique structural features present in the core-shell architecture. To this end, transmission electron microscopy (TEM) and scanning TEM (STEM) are particularly powerful tools for direct structural characterization of 2D materials with a high spatial resolution and precision. Here, we reveal and describe defects inherently present in the TMD core-shell architecture. We develop a comprehensive framework to classify the observed defects and discuss potential origins and implications of structural variations. We utilize high resolution S/TEM to reveal the relationship between defects and their associated strain fields. Furthermore, we demonstrate that TMD shells often possess a wide range of interlayer spacings with varied spatial distribution. By exploring the rich array of structural defects inherently present in the TMD core-shell architecture, we provide an important foundation to ultimately induce exotic properties in TMDs through sophisticated defect engineering.
... In nano-layers, the moiré patterns are often referred to as the moiré superstructure or superlattice 26,27 . The moiré effect in cylindrical nanoparticles, for instance, in single-and double-walled nanotubes (SWNT, DWNT) is also not unknown [28][29][30] . ...
We describe an optical phenomenon of unmovable moiré patterns in sliding (moving) grids and gratings. The phenomenon was observed visually in the planar straight movement of the black-and-white gratings with a period of several mm. This is a velocity-independent effect confirmed analytically and in a computer simulation based on the spatial averaging. We found the static directions of the moiré patterns in the regular grids, but our technique can be also applied to other objects. The orientation and period of the static moiré patterns are not obvious, especially in the presence of the distance effect. The phenomenon can be practically used in security applications.
... This flexibility is because of its 2D nature, which is analogous to the graphene (Matte et al., 2010). Numerous approaches have been made to produce MoS 2, such as the hydrothermal method (Chang and Chen, 2011b), thermal evaporation-exfoliation (Balendhran et al., 2012), physical vapor deposition (Lee et al., 2012), chemical vapor deposition (Shaw et al., 2014), chemical exfoliation (Sadan et al., 2008), mechanical exfoliation (Zhou et al., 2011), and wet chemical approaches (Altavilla et al., 2011). However, during the synthesis process, these methods led to the formation of buckyball-like nanoparticles or nanotube of MoS 2 (Rosentsveig et al., 2001;Rapoport et al., 2005). ...
Energy storage devices are the ultimate flexible solution to overcome energy deficiency. Thre is a need is to find innovative nanomaterials to overcome the delays in efficiency and sustainability. Herein, we report the synthesis of hierarchical MoS2/rGO nanohybrids as electrode material for supercapacitors. Pure phase and flower-shaped molybdenum disulfide (MoS2) nanosheets have been synthesized using a meek hydrothermal method followed by the preparation of MoS2/rGO nanohybrids. The physicochemical aspects and electrochemical properties have been carefully analyzed using cyclic voltammetry and galvanostatic charge-discharge method in the 1 M KCL electrolyte. The capacitance of MoS2 and MoS2/rGO were found to be 297 F/g (66 mAh/g or 238 C/g) and 850 F/g (153.5 mAh/g or 552.5 C/g) at 1 A/g respectively, with 95.3% retention in capacitance after 10,000 cycles at 2 A/g. The improved electrochemical performance of the MoS2/rGO electrode could be ascribed to rapid diffusion pathways delivered by rGO and improved redox reactions of hierarchical MoS2 nanosheets owing to the high surface area (391 m2/g). This feature enables a decrease in the entire impedance of electrodes which agrees with the findings obtained from electrochemical impedance spectroscopy.
