Two dimensional α-MoO3 nanoflakes obtained using solvent-assisted grinding and sonication method: Application for H2 gas sensing

Alsaif, Manal M. Y. A.; Balendhran, Sivacarendran; Field, Matthew R.; Latham, Kay; Włodarski, W.; Ou, Jian Zhen; Kalantar‐zadeh, Kourosh

doi:10.1016/j.snb.2013.10.107

Cited by 192 publications

(152 citation statements)

References 64 publications

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“…Different from other typical metal oxide semiconductors (SnO 2 or ZnO), the gas detection process of MoO 3 dominated mainly by the surface lattice oxygen rather than the chemisorbed oxygen, as shown in the schematic Figure 4a. Alsaifa et al [48][49][50] insist that hydrogen ions etc. can be intercalated into van der Waals's gaps of α-MoO 3 , accompanied with the lower oxidation state.…”

Section: Resultsmentioning

confidence: 99%

Diverse Adsorption/Desorption Abilities Originating from the Nanostructural Morphology of VOC Gas Sensing Devices Based on Molybdenum Trioxide Nanorod Arrays

Cong

Sugahara

Wei

et al. 2016

Adv Materials Inter

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attention from researchers because of their advantages of sensitivity, rapid response, and inexpensive production. [9,10] Recently, considerable effort has been devoted to developing much simpler routes to control the shape and grain size of SMO to achieve a higher surface-to-area ratio and unique surface chemistry behavior to improve sensing performance. [11][12][13] Among the metal oxides, molybdenum trioxide (MoO 3 ) is one of the most desirable for use in gas sensors because of its indirect wide band gap of 3.5 eV. [14][15][16][17] MoO 3 -based gas analyzing devices show excellent gas sensing properties for several kinds of gas species [18][19][20][21][22][23][24] because of their special quantum size effect, surface effect, high reactivity, and the polyvalency of molybdate. In particular, MoO 3 nanostructures, such as MoO 3 nanobelts, flower-like microstructured MoO 3 , and net-like MoO 3 porous architectures synthesized by the hydrothermal route, exhibit appealing sensing properties for VOC vapors. [25][26][27] The gas sensing properties of MoO 3 thin film fabricated by radiofrequency (RF) sputtering have also been investigated. [28] These reports showed the nanostructures possessed typical sensing performance for VOC vapors; however, these nanostructures need to be processed with two or more steps, which is time consuming. For instance, these nanostructures need to be transferred or arranged on a ceramic substrate and then annealed to obtain substantial growth/adhesion on the substrate. To increase the VOC gas sensing performance of nanostructures, they needed to be loaded with noble metal particles (e.g., Au, Nanorod arrays gas sensors are attracting much scientific and engineering interest because of their excellent sensing performance arising from their unique nanostructures. In this work, large-scale random 3D networks of ultrafine single-crystal α-MoO 3 nanorod arrays are applied as gas sensors. The arrays are spontaneously grown by a simple single-step solution route. A prompt response and obvious discrimination of ethanol, methanol, isopropanol, and acetone vapors at 573 K are investigated via the modulation of the resistance of the gas sensors. The sensitivity, response time, and recovery time of the sensors strongly depend on the specific morphologies of the nanorod arrays, such as length, number, and coverage of nanorods in the 3D network. A reaction mechanism in which the 3D-network nanorod arrays adsorb and react with the target molecules more readily than the seed layer is proposed to explain the different response and recovery times of the sensors. These random 3D-network nanorod arrays with functionally tunable morphology are promising for universal application as gas sensors for detecting various vapors, and provide valuable insights for the production of fast, largescale, low-cost, and simple synthesis of sensing devices.

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Section: Resultsmentioning

confidence: 99%

Diverse Adsorption/Desorption Abilities Originating from the Nanostructural Morphology of VOC Gas Sensing Devices Based on Molybdenum Trioxide Nanorod Arrays

Cong

Sugahara

Wei

et al. 2016

Adv Materials Inter

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“…A significant advantage of this approach is its versatility; it has been used to exfoliate graphene, 24,[27][28][29][30][31] BN, 15 a range of TMDs 25,26,32,33 and TMOs 34,35 as well as black phosphorus [36][37][38][39][40] and a host of other 2D materials. 41,42 Another advantage is the inherent processability of nanosheet dispersions.…”

Section: Introductionmentioning

confidence: 99%

Photoluminescence from Liquid‐Exfoliated WS₂ Monomers in Poly(Vinyl Alcohol) Polymer Composites

Vega‐Mayoral

Backes

Hanlon

et al. 2015

Adv Funct Materials

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While liquid phase exfoliation can be used to produce nanosheets stabilized in polymer solutions, very little is known about the resultant nanosheet size, thickness or monolayer content. Here we use semi-quantitative spectroscopic metrics based on extinction, Raman and photoluminescence (PL) spectroscopy to investigate these parameters for WS2 nanosheets exfoliated in aqueous polyvinylalcohol (PVA) solutions. By measuring Raman and PL simultaneously, we can track the monolayer content via the PL/Raman intensity ratio while varying processing conditions. We find the monolayer population to be maximized for a stabilizing polymer concentration of 2 g/L. In addition, the monolayer content can be controlled via the centrifugation conditions, exceeding 5% by mass in some cases. These techniques have allowed us to track the ratio of PL/Raman in a droplet of polymer-stabilized WS2 nanosheets as the water evaporates during composite formation. We find no evidence of nanosheet aggregation under these conditions although the PL becomes dominated by trion emission as drying proceeds and the balance of doping from PVA/water changes. Finally, we have produced bulk PVA/WS2 composites by freeze drying where >50% of the monolayers remain unaggregated, even at WS2 volume fractions as high as 10%.2

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“…The O1S core level spectrum of h-MoO 3 exhibit binding energy at 529.91 eV which is due to presence of lattice oxygen in MoO 3 as shown in Figure 8c. The Mo3d core level spectrum of annealed α-MoO 3 shows spin orbit doublet at 236.24 eV and 233.07 eV for Mo3d 3/2 and Mo3d 5/2 respectively confirming +6 oxidation state of molybdenum as shown in Figure 8d [41,42]. The energy difference between the doublets is 3.17eV for α-MoO 3 .…”

Section: Compositional Analysismentioning

confidence: 78%

Chemically Grown MoO3 Nanorods for Antibacterial Activity Study

Desai¹,

Mali²,

Kondalkar³

et al. 2015

J Nanomed Nanotechnol

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In the present investigation, sea urchin like morphology of h-MoO 3 nanorods are successfully synthesized by chemical bath deposition (CBD) technique. The thermal stability, structural details, morphology and compositional analysis of MoO 3 was done using thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS) techniques respectively. The thermal analysis reveals presence of sharp exothermic peak at 409ºC indicating irreversible phase transition. X-ray diffraction pattern showed hexagonal to orthorhombic phase transition after annealing at 450ºC. As synthesized h-MoO 3 shows well oriented hexagonal rods with sea urchin like architecture while that of annealed MoO 3 sample revealed 2D layer by layer growth. The SAED pattern confirms single crystalline nature of as synthesized h-MoO 3 and polycrystalline nature of annealed α-MoO 3 . While XPS study of both confirms Mo +6 and O 2-oxidation states of elements. Furthermore, characteristic antibacterial properties of h-MoO 3 and α-MoO 3 against gram positive Bacillus megaterium, Streptococcus aureus and gram negative Escherichia coli is noted.

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Two dimensional α-MoO3 nanoflakes obtained using solvent-assisted grinding and sonication method: Application for H2 gas sensing

Cited by 192 publications

References 64 publications

Diverse Adsorption/Desorption Abilities Originating from the Nanostructural Morphology of VOC Gas Sensing Devices Based on Molybdenum Trioxide Nanorod Arrays

Diverse Adsorption/Desorption Abilities Originating from the Nanostructural Morphology of VOC Gas Sensing Devices Based on Molybdenum Trioxide Nanorod Arrays

Photoluminescence from Liquid‐Exfoliated WS₂ Monomers in Poly(Vinyl Alcohol) Polymer Composites

Chemically Grown MoO3 Nanorods for Antibacterial Activity Study

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Two dimensional α-MoO3 nanoflakes obtained using solvent-assisted grinding and sonication method: Application for H2 gas sensing

Cited by 192 publications

References 64 publications

Diverse Adsorption/Desorption Abilities Originating from the Nanostructural Morphology of VOC Gas Sensing Devices Based on Molybdenum Trioxide Nanorod Arrays

Diverse Adsorption/Desorption Abilities Originating from the Nanostructural Morphology of VOC Gas Sensing Devices Based on Molybdenum Trioxide Nanorod Arrays

Photoluminescence from Liquid‐Exfoliated WS2 Monomers in Poly(Vinyl Alcohol) Polymer Composites

Chemically Grown MoO3 Nanorods for Antibacterial Activity Study

Contact Info

Product

Resources

About

Photoluminescence from Liquid‐Exfoliated WS₂ Monomers in Poly(Vinyl Alcohol) Polymer Composites