WS2 Nanotubes, 2D Nanomeshes, and 2D In-Plane Films Through One Single Chemical Vapor Deposition route
| Autor: | Adelina Ilie, David C. Hooper, Zichen Liu, Ventsislav K. Valev, Alexander W. A. Murphy, Christian Kuppe |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Chemical substance Nanowire General Physics and Astronomy 02 engineering and technology Substrate (electronics) Chemical vapor deposition Physics and Astronomy(all) 010402 general chemistry 01 natural sciences Catalysis nanotubes chemistry.chemical_compound Materials Science(all) General Materials Science Engineering(all) second harmonic generation General Engineering WS2 and WO3−x suboxides 021001 nanoscience & nanotechnology 0104 chemical sciences linear and nonlinear optical properties chemical vapor deposition growth Nanomesh Chemical engineering chemistry transition-metal dichalcogenides Nanorod two-dimensional layered materials 0210 nano-technology Stoichiometry |
| Zdroj: | Liu, Z, Murphy, A, Kuppe, C, Hooper, D, Valev, V & Ilie, A 2019, ' WS2 Nanotubes, 2D Nanomeshes, and 2D In-Plane Films Through One Single Chemical Vapor Deposition route ', ACS Nano, vol. 13, no. 4, pp. 3896–3909 . https://doi.org/10.1021/acsnano.8b06515 |
| DOI: | 10.1021/acsnano.8b06515 |
| Popis: | We demonstrate a versatile, catalyst free chemical vapor deposition process on insulating substrates capable of producing in one single stream one-dimensional (1D) WO3- x suboxides leading to a wide range of substrate-supported 2H-WS2 polymorphs: a tunable class of out-of-plane (of the substrate) nanophases, with 1D nanotubes and a pure WS2, two-dimensional (2D) nanomesh (defined as a network of webbed, micron-size, few-layer 2D sheets) at its extremes; and in-plane (parallel to the substrate) mono- and few-layer 2D domains. This entails a two-stage approach in which the 2WO3 + 7S → 2WS2 + 3SO2 reaction is intentionally decoupled. First, various morphologies of nanowires or nanorods of high stoichiometry, WO2.92/WO2.9 suboxides (belonging to the class of Magnéli phases) were formed, followed by their sulfurization to undergo reduction to the aforementioned WS2 polymorphs. The continuous transition of WS2 from nanotubes to the out-of-plane 2D nanomesh, via intermediary, mixed 1D-2D phases, delivers tunable functional properties, for example, linear and nonlinear optical properties, such as reflectivity (linked to optical excitations in the material), and second harmonic generation (SHG) and onset of saturable absorption. The SHG effect is very strong across the entire tunable class of WS2 nanomaterials, weakest in nanotubes, and strongest in the 2D nanomesh. Furthermore, a mechanism via suboxide (WO3- x) intermediate as a possible path to 2D domain growth is demonstrated. 2D, in-plane WS2 domains grow via "self-seeding and feeding" where short WO2.92/WO2.9 nanorods provide both the nucleation sites and the precursor feedstock. Understanding the reaction path (here, in the W-O-S space) is an emerging approach toward controlling the nucleation, growth, and morphology of 2D domains and films of transition-metal dichalcogenides. |
| Databáze: | OpenAIRE |
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