Molybdenum Trioxide Nanobelts Research Articles

Enhanced dielectric properties of α-MoO3 nanobelts dispersed polyethylene oxide-carboxymethyl cellulose matrix-based nanocomposites

Highly crystalline molybdenum trioxide nanobelts (MoO3 NBs) are synthesized via one-step hydrothermal method and the resulting NBs are incorporated with poly(ethylene oxide) (PEO)/carboxymethyl cellulose (CMC) blend matrix via a solution-casting method to be applicable in various nanoelectronics. The structural, optical, and dielectric characteristics of the polymer nanocomposite PEO/CMC-(x)MoO3 (x = 2, 4, 6, and 8 %wt) films are comprehensively examined by different techniques, including X-ray diffraction (XRD), Fourier-transform infrared (FTIR), ultraviolet–visible (UV–Vis) spectroscopy, and broadband dielectric spectroscopy. XRD results confirm the presence of nanofiller in the (PEO/CMC) blend at a higher fraction (8 wt%). Furthermore, FTIR investigations show an electrostatic interaction between the PEO/CMC polymer composite and MoO3 nanobelts, leading to the generation of metal oxides/polymer complexes. Optical properties of the synthesized PEO/CMC-(x) MoO3 matrix, including direct and indirect bandgap energies are decreased by increasing the content of MoO3 NBs in the PEO/CMC blend matrix, showing the promise of photocatalytic activity. The AC conductivity and dielectric parameters (ε′ and ε′′) are markedly increased at a higher fraction of MoO3 (8 wt%). The optical and electrical conductivity properties of the synthesized PEO/CMC-(x) MoO3 design confirms its ability to be used in optoelectronic devices.

One-pot synthesis of molybdenum trioxide nanobelts for high performance catalytic oxidative desulfurization of dibenzothiophene

One-pot synthesis of molybdenum trioxide nanobelts for high performance catalytic oxidative desulfurization of dibenzothiophene

NIR‐II Photo‐Amplified Sonodynamic Therapy Using Sodium Molybdenum Bronze Nanoplatform against Subcutaneous Staphylococcus Aureus Infection

AbstractUltrasound (US)‐mediated sonodynamic therapy (SDT) has the advantages of non‐invasiveness and deep tissue penetration. Nanosystems are prominently used in sonosensitization; however, most nano‐sonosensitizers have a low reactive oxygen species (ROS) yield, thus restraining the application of SDT. Sodium molybdenum bronze nanoparticles (SMB NPs) with rich oxygen vacancies are developed and interlayer gaps of molybdenum trioxide nanobelts are expanded. Owing to the increased oxygen vacancy density and wide interlayer gap‐induced narrower band gap of SMB NPs, the electrons (e–) and holes (h+) generated by US are separated more rapidly, and oxygen vacancies prevent electrons–holes recombination under US irradiation. SMB NPs exhibit a second near‐infrared (NIR‐II) photothermal effect to promote the generation of ROS by the sonosensitizer. The SMB NPs system is successfully realized to eliminate Staphylococcus aureus (S. aureus) and dissipate biofilm. Therefore, multimodal therapy using SMB NPs serves as an effective and promising regimen for deep‐seated bacterial infections. The newly developed Mo‐based sonosensitizer is presented for the first time to demonstrate excellent antimicrobial activity through hyperthermia‐promoting SDT therapeutics. This work proposes a novel strategy in the field of NIR‐II photo‐amplified SDT with Mo‐based materials for bacterial eradication and other important biomedical applications.

One-Pot Pulsed Laser Ablation Route Assisted Molybdenum Trioxide Nano-Belts Doped in PVA/CMC Blend for the Optical and Electrical Properties Enhancement

One-Pot Pulsed Laser Ablation Route Assisted Molybdenum Trioxide Nano-Belts Doped in PVA/CMC Blend for the Optical and Electrical Properties Enhancement

Mechanical design of brush coating technology for the alignment of one-dimension nanomaterials

Widespread approaches to fabricate surfaces with aligned nanostructured topographies have been stimulated by opportunities to enhance interface performance by combing physical and chemical effects, in which brush-coating technology (BCT) is a cost-effective and feasible method for aligned film and large-scale production. Here, we reported a BCT process to realize the alignment of various 1D nanostructures through mechanical design that provides a more precise and higher shear force. By regulating the viscosity of dispersion, shear force is proved to be 24 and 20.3 times larger (when the volume ratio of water and glycerol is 1:3) according to the theoretical calculation and ANSYS simulating calculation results respectively, which plays a vital role in brush coating process. The universality was demonstrated by the alignment of one-dimension nanomaterials with different diameters, including silver nanowires (~80 nm), molybdenum trioxide nanobelts (~150 nm), vanadium pentoxide nanobelts (~150 nm) and bismuth sulfide nanobelts (~200 nm), et al., which in consequence have different alignment ratios. Meanwhile, anisotropic and flexible electrical conductors (the resistance anisotropic ratio was 2) and thermoelectric films (Seebeck coefficient was calculated to be 56.7 µV/K) were demonstrated.

Ethanol-sensing properties of α-MoO3 nanobelts synthesized by hydrothermal method

Orthorhombic molybdenum trioxide nanobelts were successfully synthesized by a facile hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Gas sensing properties of the prepared α-MoO3 nanobelt sensors to ethanol, methanol and acetone vapors were investigated. The α-MoO3 nanobelt sensors show strongest response of 174 for 800 ppm ethanol vapor operating at 300 °C,which is much stronger than the response to methanol and acetone vapor. Generally the response times to ethanol vapor (5-800 ppm) decrease with the increase of operating temperature, from 33 to 61 s at 250 °C to 9–14 s at 400 °C, while the recovery times show a decrease trend with the increase in the concentration of ethanol vapor. The sensing mechanisms responsible for α-MoO3 nanobelt to ethanol vapor are discussed.

Flexible Transparent Molybdenum Trioxide Nanopapers for Supercapacitors

Free-standing paper-like film with excellent transparency and flexibility holds great potential to serve as a transparent electrode for wearable electronics and energy storage. Transition metal oxide have shown their great potential for energy storage due to their high capacitance and stability. Nevertheless, the fabrication of ultrathin transparent paper electrode via the assembly of 1D transition metal oxide nanostructure has never been reported. Orthorhombic molybdenum trioxide (α-MoO3), transition metal oxide with layered structures, has been recognized as a promising electrode for energy storage. In this talk, I will talk about the fabrication of flexible and transparent MoO3 nanopapers via assembly of ultralong molybdenum trioxide nanobelts (MoO3 NBs) and their application for high-performance supercapacitor electrodes. The well-dispersed, ultralong MoO3 NBs with an average length of 200 µm have been synthesized via a hydrothermal method. A flexible transparent molybdenum trioxide nanopaper via the assembly of these ultralong nanobelts displays an excellent average transmittance of 90% in the visible region. Significantly, the freestanding nanopaper electrode delivers an outstanding specific capacitance of 1198 F g-1 at 2 mV s-1, which is just slightly below the theoretical value of molybdenum trioxide (1256 F g-1). The excellent specific capacitance can be ascribed to the efficient ion diffusion in the 3D structure and the very thin nanobelts, as well as the reduced distance of electron transport from transparent nanopaper electrode to current collector. The nanopaper-based supercapacitor device also shows an excellent long-term stability performance over 20,000 cycles with a retention rate of 96.5%. Figure 1

High-performance lithium storage properties based on molybdenum trioxide nanobelts

Orthorhombic molybdenum trioxide (α-MoO3) nanobelts were successfully synthesized via a facile hydrothermal approach, and the lithium storage properties of α-MoO3 nanobelts were investigated. The α-MoO3 nanobelts anode delivered a high first specific discharge (lithiation) capacity of 1351 mA h g−1 at 0.2 A g−1, good capacity retention (over 900 mA h g−1 after 60 cycles at 0.2 A g−1) and impressive rate performance. The excellent electrochemical properties of the α-MoO3 electrode enable its application in the fields of energy storage and conversion.

Electrocatalysis on Separator Modified by Molybdenum Trioxide Nanobelts for Lithium–Sulfur Batteries

AbstractLithium–sulfur batteries (LSBs) have been regarded as the supreme feasible future generation energy storage system for high‐energy applications due to the exceptional‐specific energy density of 2600 Wh kg−1 and theoretical‐specific capacity of 1675 mAh g−1. Nevertheless, some key challenges which are linked with polysulfide shuttling and sluggish kinetics of polysulfide conversion are the main obstacles in the high electrochemical performance of LSBs. Here, a molybdenum trioxide (MoO3) nanobelt catalytic layer is fabricated on the separator to solve these issues. The MoO3 layer shows strong chemical interaction with polysulfides by successfully blocking the polysulfides on the separator from shuttling and significantly accelerates the redox reaction of polysulfide conversion. Furthermore, the randomly arranged layers of MoO3 nanobelts possess enough porous networks that provide effective space for electrolyte infiltration and facile pathway for fast ion transportation. The resultant LSBs exhibit a very high initial capacity of 1377 mAh g−1. After 200 cycles at 0.5 C, the capacity is 684.4 mAh g−1 with the fading rate of only 0.251% per cycle. Additionally, the MoO3 modification provides good surface protection of lithium anode and depresses the lithium anode degradation.

Fabrication of Molybdenum Trioxide Nanobelts as High Performance Supercapacitor

Electrochemical supercapacitors based on transition metal oxides nanostructures have aroused much attention for energy storage and conversion owing to their ability to intercalate ions in a wide range of sites. In this work, we have reported electrochemical properties of molybdenum trioxide (MoO3) nanobelts synthesized via facile low temperature hydrothermal method and used it as an electrode material for the supercapacitor applications. The morphology and crystal structure of the MoO3 nanobelts have been characterized by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscope (HRTEM) and X-ray powder diffraction (XRD) respectively. The BET surface area was found to be 59.285 m2 g-1. The supercapacitor performances of the nanobelts electrodes have been investigated by cyclic voltammetry (CV). The MoO3 based supercapacitor shows a specific capacitance as high as 256.83 F g-1 at a scan rate of 5 mV s-1 in 0.5 M Na2SO4 aqueous electrolyte solution. Moreover, the low series resistance (1.20 Ω) and charge transfer resistance (3.85 Ω) values at high frequency range obtained from MoO3 electrode indicate that it is a promising supercapacitor electrode material and suitable for other electrochemical applications. In addition, MoO3 supercapacitor electrode shows high electrochemical stability and can withstand over 200 cycles with no obvious change in the CV curves.

Flexible Transparent Molybdenum Trioxide Nanopaper for Energy Storage.

A flexible transparent molybdenum trioxide nanopaper, assembled via ultralong molybdenum trioxide nanobelts, displays an excellent average transmittance of ≈90% in the visible region. The free-standing nanopaper electrode delivers an outstanding specific capacitance of 1198 F g(-1) and shows an excellent long-term stability performance over 20 000 cycles with a retention rate of 99.1%.

Large-scale synthesis of single-crystal molybdenum trioxide nanobelts by hot-wire chemical vapour deposition

Bulk quantities of molybdenum trioxide (α-MoO3) nanobelts were synthesized via hot wire chemical vapor deposition on the surface of the MoSi2 rod electric heater at 600°C under air atmosphere. The MoO3 nanobelts grown on each MoSi2 rod were up to 20g in weight. The possible vapor–solid growth mechanism was discussed. Before the growth of MoO3 nanobelts, SiO2 protective layers of MoSi2 rod electric heater were deoxidized by the carbothermal reduction reaction, and Mo2C was formed on the surface of the MoSi2 rods. When Mo2C was oxidized under air atmosphere, MoO vapor was deposited on the hot MoSi2 rod surface to form yellow MoO3 nanobelts. The hot wire chemical vapor deposition technique is desirable for the large-scale production of MoO3 nanomaterials.

Characteristics of molybdenum trioxide nanobelts prepared by thermal evaporation technique

Single-crystalline nanobelts of molybdenum trioxides (MoO 3) were grown by a thermal evaporation method of molybdenum metal pellets at ambient pressure in a flow of O 2. The chemical composition, crystalline structure and optical properties of the nanobelts were investigated by various characterization techniques such as scanning electron microscopy, transmission electron microscopy, Raman-scattering, energy dispersive X-ray spectroscopy and UV–vis-NIR spectroscopy. The samples were nanobelts with a width up to 50 μm, about 85 nm in thickness and from tens to several hundred micrometers in length. The analysis indicated that as-synthesized samples were orthorhombic structured MoO 3 grown with [0 0 1] preferred orientation. The fundamental optical absorption edge corresponds to direct allowed transitions with an energy gap located at about 3.01 eV.

Synthesis and Electrochemical Performance of PEO Doped Molybdenum Trioxide Nanobelts

Synthesis and Electrochemical Performance of PEO Doped Molybdenum Trioxide Nanobelts

Morphology-Controllable Synthesis and Characterization of Single-Crystal Molybdenum Trioxide

Molybdenum trioxide nanobelts and prism-like particles with good crystallinity and high surface areas have been prepared by a facile hydrothermal method, and the morphology could be controlled by using different inorganic salts, such as KNO3, Ca(NO3)2 , La(NO3)3, etc. The possible growth mechanism of molybdenum trioxide prism-like particles is discussed on the basis of the presence of H+ and the modification of metal cations. The as-prepared nanomaterials are characterized by means of powder X-ray diffraction (PXRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transformation infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and ultraviolet and visible spectroscopy (UV-vis). TEM and HRTEM micrographs show that the molybdenum trioxide nanobelts and prism-like particles have a relatively high degree of crystallinity and uniformity. BET specific surface areas of the as-prepared molybdenum trioxide nanocrystals are 67-79 m2 g-1. XPS analysis indicates that the hexavalent molybdenum is predominant in the nanocrystals. UV-vis spectra reveal that the direct band gap energy of the annealed molybdenum trioxide prism-like particles shows a pronounced blue shift compared to that of bulk MoO3 powder. Interestingly, molybdenum trioxide nanobelts exhibit a red shift under this condition.