First-Principles Evaluation of the Morphology of WS<sub>2</sub> Nanotubes for Application as Visible-Light-Driven Water-Splitting Photocatalysts

Piskunov, Sergei; Lisovski, Oleg; Zhukovskii, Yuri F.; D’yachkov, P. N.; Ėvarestov, R. A.; Kenmoe, Stéphane; Spohr, Eckhard

doi:10.1021/acsomega.8b03121

Cited by 31 publications

(20 citation statements)

References 51 publications

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“…In the double wall nanotubes (see Tables II and III of the supplementary material), the electronic gap is in between the gaps of the two isolated single wall tubes forming the double wall tube. Our calculated gaps are in good agreement with those reported by S. Piskunov et al, 51 and the trend with nanotube diameter is the same.…”

Section: Theoretical Calculationssupporting

confidence: 92%

“…We now turn to compare the calculations with the experimental results for the CL presented above. Previous studies on WS 2 and analogous MoS 2 nanotubes 22,23,51 have found that their stabilities, as measured by the strain energy, follow the 1/D 2 behavior, where D is the external diameter of the nanotubes (diameter of the external S layer of the exterior S-W-S trilayer). Our results for the strain energy per atom, plotted in Fig.…”

Section: Theoretical Calculationsmentioning

confidence: 97%

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Cathodoluminescence in single and multiwall WS2 nanotubes: Evidence for quantum confinement and strain effect

Ghosh

Brüser

Kaplan‐Ashiri

et al. 2020

Applied Physics Reviews

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For nanoparticles with sub-10 nm diameter, the electronic bandgap becomes size dependent due to quantum confinement; this, in turn, affects their electro-optical properties. Thereby, MoS 2 and WS 2 monolayers acquire luminescent capability, due to the confinement-induced indirect-to-direct bandgap transition. Rolling up of individual layers results in single wall inorganic nanotubes (SWINTs). Up to the present study, their luminescence properties were expected to be auspicious but were limited to theoretical investigations only, due to the scarcity of SWINTs and the difficulties in handling them. By optimizing the conditions in the plasma reactor, relatively high yields of WS 2 SWINTs 3-7 nm in diameter were obtained in this work, compared to previous reports. A correlative approach, transmission electron microscopy coupled with a scanning electron microscope, was adapted to overcome handling obstacles and for testing individual nanotubes by lowtemperature cathodoluminescence. Clear cathodoluminescence spectra were obtained from WS 2 -SWINTs and compared with those of WS 2 multiwall nanotubes and the corresponding bulk material. Uniquely, the optical properties of INTs acquired from cathodoluminescence were governed by the opposite impact from quantum size effect and strain in the bent triple S-W-S layers. The experimental findings were confirmed by the Density Functional and Time-Dependent Density Functional theoretical modeling of monolayer and bilayer nanotubes of different chiralities and diameters. This study provides experimental evidence of the quantum confinement effect in WS 2 SWINTs akin to WS 2 monolayer. The ability to tune the electronic structure with morphology or number of layers may be exploited toward photoelectrochemical water splitting with WS 2 catalysts, devising field effect transistors, photodetectors, and so on.

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Section: Theoretical Calculationssupporting

confidence: 92%

Section: Theoretical Calculationsmentioning

confidence: 97%

Cathodoluminescence in single and multiwall WS2 nanotubes: Evidence for quantum confinement and strain effect

Ghosh

Brüser

Kaplan‐Ashiri

et al. 2020

Applied Physics Reviews

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“…Structural planes were determined using computational analysis, some of which are identified in Figure b, corresponding to monoclinic WO 3 nanostructures, with d -spacings of 3.8 Å. It is noteworthy to highlight that in the WO 3 spectra, the peak marked with (*) in Figure b overlaps with the (004) and (101) planes (2θ = 28.8 and 33.6°, respectively) of the WS 2 NTs. , Broadening of these XRD peaks in the WS 2 NTs spectrum is attributed to the submicron sizes of the NTs.…”

Section: Resultsmentioning

confidence: 99%

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Magee

Tang

Ozdemir

et al. 2022

ACS Appl. Nano Mater.

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Multi-walled WS 2 nanotubes (NTs) with lengths ranging from 2 to 65 μm and widths from 50 to 110 nm were synthesized in a horizontal quartz-made reactor by a process yielding NTs with aspect ratios (ARs) between ∼40 and >1000. The NTs obtained were thermally stable in air up to 400 °C but were oxidized within the temperature range 400−550 °C to produce yellow WO 3 particles. Critically, 400 °C is well above the temperature used to mix additives with the majority of meltprocessable polymers. The hydrophilic WS 2 NTs were easily dispersed in poly(lactic) acid (PLA) using a twin-screw extruder, but the shear stresses applied during melt mixing resulted in chopping of the NTs such that the AR decreased by >95% and the tensile mechanical properties of the PLA were unchanged. Although the as-extruded unfilled PLA was >99% amorphous, the much-shortened WS 2 NTs had a significant effect on the crystallization behavior of PLA, inducing heterogeneous nucleation, increasing the crystallization temperature (T c ) by ∼3 °C and the crystalline content by 15%, and significantly increasing the rate of PLA crystallization, producing smaller and more densely packed spherulites. The reduction in the AR and the nucleating effect of WS 2 NTs for PLA are critical considerations in the preparation, by melt mixing, of composites of rigid 1D NTs and polymers, irrespective of the target application, including bone tissue engineering and bioresorbable vascular scaffolds.

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“…Beside the UV counterpart, about 46% of visible and 48% infrared light accounts for the total solar spectrum. [20,21] A variety of wide and narrow band gap photocatalysts and their composites, such as SrTiO 3 , [22,23] TiO 2 , [24,25] ZnO, [26,27] BiVO 4 , [28,29] Bi 2 WO 6 , [30,31] Cu 2 O, [32] CdS, [33,34] r-GO, [35,36] g-C 3 N 4 , [4,[37][38][39] MoS 2 , [40,41] MoSe 2 , [42][43][44] WS 2 , [45][46][47] Fe 2 O 3 , [48,49] LaFeO 3 , [10,50] BiFeO 3 , [50,51] CulnS 2 , [52] copper chalcogenide, [53,54] double-layered hydroxides (LDH), [55,56] and semiconductor quantum dots, [57] etc., have been assessed so far in photocatalysis for water reduction, CO 2 conversion and pollutant degradation. Thus, a single semiconductor photocatalyst always exhibit low photocatalytic efficiency owing to the low solar energy harvesting and poor charge carrier's separation.…”

Section: Introductionmentioning

confidence: 99%

Recent Progress in the Synthesis and Applications of Composite Photocatalysts: A Critical Review

2021

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concentration for March 2021 was 417.14 parts per million (ppm), which is about 50% higher than the average for pre-industrial levels (i.e., 278 ppm). In order to control global warming, the CO 2 emission must fall by 25% to keep the temperature below 2 °C threshold relative to the pre-industrial climate. [3,4] Among the existing numerous renewable and sustainable energy resources such as wind, solar, hydropower, geo-thermal and ocean-energy, the consumption of unlimited solar energy become a vital alternative energy source, and has been extensively explored during the past few decades. [5] For instant, solar energy could be employed practically in photocatalysis for water splitting to generate hydrogen, carbon dioxide conversion to value added products, and pollutant oxidation. [6][7][8] Photocatalysis has advantage over conventional biological, incineration, electrocatalytic, adsorption, and air stripping treatment techniques because these methods always exhibit shortfalls such as instability, catalyst poisoning, low production yield, poor mechanical strength, time consuming, and electrode corrosion. [9,10] Generally, the photocatalytic process involves several essential steps such as the light absorption by photocatalyst to generate charge carriers, charge carrier's separation and migration to the photocatalyst surface, and the surface redox reactions to transform solar energy into chemical energy. [11,12] If these essential steps are satisfied by a proficient photocatalyst, then of course, high photocatalytic efficiency could be expected. Generally, the fundamental features of a photocatalyst include appropriate band gaps with their corresponding valence and conduction band potentials, surface active sites, surface area, and optical absorption behavior that govern the efficiency and effectiveness of photocatalytic processes. [13,14] Since the photocatalytic reactions are typically performed in water and air environments, therefore, the photocatalyst stability could be crucial under these circumstances. [15] Fujishima and Honda performed water splitting reaction for the first time in 1972, while utilizing TiO 2 photoanode with the aid of Pt as a counter electrode. [16] Afterward, TiO 2 photocatalyst received marvelous attention in photocatalysis owing to its promising features such as its non-toxic nature, water insolubility, nature abundant, hydrophilicity, high stability, and appropriate valence and conduction band potentials for redox reactions. [17] Yet, the Photocatalysis is an advanced technique that transforms solar energy into sustainable fuels and oxidizes pollutants via the aid of semiconductor photo catalysts. The main scientific and technological challenges for effective photocatalysis are the stability, robustness, and efficiency of semiconductor photocatalysts. For practical applications, researchers are trying to develop highly efficient and stable photocatalysts. Since the literature is highly scattered, it is urgent to write a critical review that summarizes the stateof theart progress in the ...

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First-Principles Evaluation of the Morphology of WS₂ Nanotubes for Application as Visible-Light-Driven Water-Splitting Photocatalysts

Cited by 31 publications

References 51 publications

Cathodoluminescence in single and multiwall WS2 nanotubes: Evidence for quantum confinement and strain effect

Cathodoluminescence in single and multiwall WS2 nanotubes: Evidence for quantum confinement and strain effect

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Recent Progress in the Synthesis and Applications of Composite Photocatalysts: A Critical Review

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First-Principles Evaluation of the Morphology of WS2 Nanotubes for Application as Visible-Light-Driven Water-Splitting Photocatalysts

Cited by 31 publications

References 51 publications

Cathodoluminescence in single and multiwall WS2 nanotubes: Evidence for quantum confinement and strain effect

Cathodoluminescence in single and multiwall WS2 nanotubes: Evidence for quantum confinement and strain effect

WS2 Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Recent Progress in the Synthesis and Applications of Composite Photocatalysts: A Critical Review

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Product

Resources

About

First-Principles Evaluation of the Morphology of WS₂ Nanotubes for Application as Visible-Light-Driven Water-Splitting Photocatalysts

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture