Search

Molybdenum Trioxide (MoO3) films are grown on Si(100) substrates by reactive RF magnetron sputtering in plasma containing a mixture of Argon and Oxygen, using a pure Molybdenum target. In this paper, we report the deposition of (MoO3) films on Si(100) substrates under varying gas flow (O2 + Ar gas) (20 sccm to 30 sccm with the duration of deposition~ 1hr) by RF reactive magnetron sputtering at room temperature. To get crystalline MoO3 films annealing in O2 environment at 500 °C for 4 h is done. Phase formation and orientation of the film is characterised by Glancing incidence X-ray diffraction (GIXRD). The identification of the orthorhombic MoO3 phase is investigated by XRD and Raman spectroscopy. Raman lines at 819 cm-1 and 995 cm-1 are due to the (A1g, B1g) symmetric stretching (Mo-O-Mo) bond and asymmetric stretching band (Mo=O) respectively. Surface morphology and cross-sectional image of the deposited thin films were investigated by FE-SEM image. UV-Visible reflectance and cross-sectional FE-SEM image confirm the thickness of the MoO3 films with oxygen-rich and oxygen deficient phase formation occur. Reverse leakage current density of 20 sccm 1hr sample is low (1×10-6 mA/cm2) as compared to 30 sccm 1hr sample (1×10-3 mA/cm2). The higher leakage is due to crack formation during the ex-situ annealing of MoO3 films. This MoO3 films can be used in Gas sensing and switching devices. [ABSTRACT FROM AUTHOR]

• MoO 2 spheres with a novel mesoporous structure is fabricated for supercapacitor. • The capacitive behavior of MoO 2 and MoO 3 are evaluated and compared. • The MoO 2 shows a specific capacitance of 381.0 F g−1, 7 times higher than MoO 3. MoO 2 and MoO 3 with specific morphologies are synthesized on flexible carbon cloth through a facile hydrothermal method as supercapacitor electrodes. The prepared prismatic MoO 3 shows a specific capacitance of 54.7 F g−1 in 1 M LiOH electrolyte. Moreover, the prepared MoO 2 presents a spherical profile with hierarchical porous structure. Each MoO 2 sphere is stacked with several layers of MoO 2 "spindle" which is further built by amounts of MoO 2 nanoparticles. A high specific capacitance of 381.0 F g−1 is achieved for the MoO 2 sphere electrode, 7 times higher than that of MoO 3. [ABSTRACT FROM AUTHOR]

All-inorganic perovskite CsPbI 2 Br has received much attention recently due to its suitable bandgap and excellent thermal stability. Herein, we demonstrated a low temperature solution process to obtain high quality CsPbI 2 Br films and fabricate devices with a facile n-i-p structure (ITO/SnO 2 /CsPbI 2 Br/Spiro-OMeTAD/MoO 3 /Ag), in which MoO 3 was introduced as interfacial layer that led to high efficient charge extraction and suppressed carrier recombination. As a result, the champion cells exhibited a relatively high power conversion efficiency of 14.05% and superb fill factor of 81.5%. More importantly, unencapsulated PSCs with MoO 3 interfacial layers showed outstanding stabilities with retaining 80% of initial PCE with thermal treatment at 85 °C for 140 min in ambient air, 80% of initial PCE under continuous illumination for 120 min in ambient air, and 89% of initial PCE after being stored in N 2 glove-box over 60 days. Meantime, it should be mentioned that all interlayers and active layer were processed at temperature below 160 °C, and hence, this fabrication technique is promising for flexible energy devices and future commercialization. Low temperature processed high performance all-inorganic perovskite solar cells with MoO 3 as interfacial layer have been achieved with PCE exceeding 14% via sequential graded thermal annealing process. Moreover, the unencapsulated device exhibited enhanced operational stability under continuously simulated sunlight illumination, thermal stability and outstanding air stability after 60 days of storage under N 2 condition. Image 1 • High performance with PCE of 14 % and FF of 81.5 % are achieved by using low temperature solution processed CsPbI 2 Br. • The MoO 3 interfacial layer has been introduced to enhance charge extraction and suppressed carrier recombination. • The unencapsulated device exhibited enhanced operational stability and thermal stability. [ABSTRACT FROM AUTHOR]

Abstract Herein, we present the synthesis of oxygen vacancies-rich α -MoO 3- x nanobelts through a novel defect-engineering strategy. The oxygen-vacancies could not only greatly increase the interlayer spacing and the electrical conductivity of MoO 3 , but also significantly enhance the electrochemical activity, which promotes faster charge storage kinetics. Meanwhile, to further facilitate the electron transfer and ion transport, a graphene nanomesh-carbon nanotube/MoO 3- x (GC/MoO 3- x) nanocomposite with three-dimensional sandwiched structure was fabricated, which displays high specific capacity up to 306 C g−1 as well as high volumetric capacity of 692 C cm−3. Our fabricated asymmetric supercapacitor (ASC) with the GC/MoO 3- x and GC/MnO 2 nanocomposites as anode and cathode, respectively, exhibits an ultrahigh energy of 150 Wh kg−1, corresponding to an impressive volumetric energy density of 319 Wh L−1. Notably, both the gravimetric and volumetric energy densities are much higher than most of the previously reported metal oxide based ASCs in aqueous electrolytes. Furthermore, the ASC displays an ultra-long lifespan with 101% retention ratio after 30,000 cycles. The outstanding performances of GC/MoO 3- x composite render it a highly promising candidate for next-generation supercapacitors with both high energy and power densities in future applications, especially in greatly limited space. Graphical abstract fx1 Highlights • Oxygen vacancies-rich MoO 3- x is prepared through a novel defect-engineering strategy. • Oxygen-vacancies greatly increase the interlayer spacing, electrical conductivity and electrochemical activity of MoO 3. • High specific capacity up to 306 C g−1 (692 C cm−3) is obtained. • An ultrahigh volumetric energy density of 319 Wh L−1 is obtained, the highest value for aqueous supercapacitors up to date. • ASC displays an ultra-long lifespan with 101% retention ratio after 30,000 cycles. [ABSTRACT FROM AUTHOR]

Abstract MoO 3 /SiO 2 catalysts were prepared by impregnation, co-precipitation and stepwise precipitation, respectively. Their textural structure and physicochemical properties were characterized by low temperature N 2 adsorption, SEM, TEM, and NH 3 -TPD technologies, and their catalytic activity was tested using the hydrodeoxygenation of guaiacol in an autoclave. SP-MoO 3 /SiO 2 catalyst prepared by stepwise precipitation exhibits the highest catalytic activity for conversion of guaiacol to aromatic hydrocarbons. Direct cleavage of the C-O bond by hydrolysis over oxygen vacancy of MoO 3-x is dominant during the HDO of guaiacol, leading to the high selectivity for arenes. In addition, large amount of toluene was found in the product over SP-MoO 3 /SiO 2 catalyst, suggesting that the methyl transfer reaction can be promoted by the strong acidity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reduction in HOMO and LUMO in Mo 7 O n as n increases from 0 to 21. • C O stretching frequencies increase and CO binding energies decrease in COMo 7 O n as n increases. • C O stretching frequency in COMo 7 O 21 is 55 cm−1 higher than in the gas phase CO. • CO is an electron density donor in COMo 7 O 21 and acceptor in COMo 7 O n (n less than 21) Molybdenum oxide has a broad range of applications in areas such as catalysis, antimicrobial coatings, medicine, and sensors. In this study, we have investigated the geometric and electronic structure, thermal stability, and chemical reactivity of molybdenum oxide at different oxidation and electronic charge states using cluster models of Mo 7 O n with density functional theory calculations. A decrease in the energy of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) has been identified as n increases from 0 to 21. Ionization potential and electron affinity of Mo 7 O n correlate strongly with the energies of HOMO and LUMO, and both increase with increasing n. We have identified the most stable CO binding sites on Mo 7 O n , calculated CO binding energy and simulated IR absorption spectrum of COMo 7 O n. An n -dependent increase in C O stretching frequencies and decrease in CO binding energies indicate that electron backdonation from Mo 7 O n to CO governs the changes in CO binding energy as a function of oxide composition. C O stretching frequency in COMo 7 O 21 is 2197 cm−1, which is 55 cm−1 higher than in the gas phase CO molecule, indicating that CO is an electron density donor and the oxide acts as an electron acceptor at this stoichiometric composition. Comparing CO binding energies in neutral and ionic (q=+/-1) COMo 7 O n , there is, in average, a stabilizing effect of excess (missing) charge on CO binding energy at low (high) n. [ABSTRACT FROM AUTHOR]

Pure MoO3 photocatalyst was prepared and simultaneously modified with graphene-like BN by a facile method which had attracted much attention. The samples were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectra (FT-IR). The hybrids showed higher photocatalytic activity toward the decomposition of the RhB molecules under visible light irradiation than the pure MoO3, and the results indicated that the optimal loading amount of graphene-like BN was 3 wt%. The results of the photocurrent and impedance analysis manifested that a small amount of graphene-like BN was beneficial for the separation of photogenerated electrons and holes, and then could enhance the photoactivity of graphene-like BN/MoO3. Based on the experimental results, a possible visible-light photocatalytic degradation mechanism was also discussed. [ABSTRACT FROM AUTHOR]

Cordierite (MAS) is difficult to sinter because of the very narrow sintering temperature range (1300-1400°C). Because a low temperature process is desirable, it is necessary to find functional ads which can allow easier sintering process at lower temperature. The influence of MoO3 on the preparation process of cordierite ceramics was investigated. 2MgO-2Al2O3-5SiO2 was researched by sintering followed binary systems: MgO/MoO3, Al2O3/MoO3 and SiO2/MoO3 (all sintered at 850°C and 1100°C, sintering time 2h). Composition of these systems was 80 mass% of oxide and 20 mass% MoO3. The effects of sintering, the composition and morphology were followed by X-ray diffraction and SEM microscopy. It has been found that MoO3, beside liquid phase, forms intermediary unstable compounds with MgO and Al2O3, which is the significance information for further research. MAS ceramics were sintered with 20 mass% MoO3 at 1100°C, 1200°C and 1300°C, during 2h. [ABSTRACT FROM AUTHOR]

The composited photocatalyst of Ag-MoO3 was prepared via the solid phase eutectic method. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectrometer (EDS), UV-vis diffuse reflectance spectra (UV-vis DRS) and Fourier transform infrared (FT-IR). Results show that the Ag could be effectively doped into MoO3, and the doping could effective enhance the adsorption of visible light. The photocatalytic influence of doping Ag into MoO3 was investigated by degradation of methylene blue (MB). The result shows that Ag doping could restrain the adsorption of MoO3, exhibit better photo-catalytic activity, but the degradation rate of MB was reduced under the same conditions. [ABSTRACT FROM AUTHOR]

Abstract: Small molecular organic solar cells (OSCs) with an inverted structure of indium tin oxide (ITO)/cesium carbonate (Cs2CO3)/C60/subphthalocya- nine(SubPc)/molybdenum oxide (MoO3)/Ag were fabri- cated and studied. By using the equivalent circuit model and transfer matrix theory, the influence of the thickness of MoO3 on the electrical and optical characteristics of the device was systematically investigated. The results indicate that at the optimized thickness of 15nm, the power conversion efficiency was increased to 0.57% under AM 1.5 solar illumination at an intensity of 100 mW/cm2. The enhancement of the device performance was attributed to the optical spacer effect and the good protection of active layer from Ag diffusion and charge extraction without introducing more series resistance. Finally, the lifetime measure- ment showed that the stability of OSCs was remarkably enhanced by introducing inverted structure. [Copyright &y& Elsevier]

MoO3/TiO2/fly-ash cenospheres photocatalyst has been synthesized via a simple sol-gel method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible diffuse reflection spectrum (UV-VIS DRS) in detail. The results indicate that MoO3/TiO2 binary compound film was well deposited onto the fly-ash cenospheres. The photocatalyst gives a better response to the visible light range, and its photocatalytic activity was evaluated by degradation of methylene blue under visible light irradiation. The photocatalyst of MoO3/TiO2/fly-ash cenospheres with 9 wt % of Mo has the highest decolorization rate (95.6 %) under visible light irradiation for 20 min. MoO3 takes an important role to improve the photo-decolorization rate by decreasing the recombination of the electrons and holds. [ABSTRACT FROM AUTHOR]

Abstract: We study the effect of indium tin oxide (ITO) cleaning and hole-injection layer (HIL) insertion on performance of organic light emitting diodes (OLEDs) device, especially the degradation. We prepare higher- and lower-level cleaned ITOs and molybdenum oxide (MoO3) as HIL. OLED with higher-level cleaned ITO and without MoO3 gives the lower driving voltage, while a good stability in chromaticity and power efficiency is obtained from OLEDs with MoO3. The degradation of power efficiency is reduced in OLEDs with MoO3 and lower-level cleaned ITO. [Copyright &y& Elsevier]

Chicken poultry industry produces a vast amount of feather waste and is often disposed into landfills, creating environmental pollution. Therefore, we explored the valorization of chicken feather waste into lipids and keratinous sludge biomass. This study demonstrates the successful utilization of keratinous sludge biomass as a unique precursor for the facile preparation of novel keratinous sludge biomass-derived carbon-based molybdenum oxide (KSC@MoO 3) nanocomposite material using two-step (hydrothermal and co-pyrolysis) processes. The surface morphology and electrochemical properties of as-prepared nanocomposite material were analyzed using HR-SEM, XRD, XPS, and cyclic voltammetric techniques. KSC@MoO 3 nanocomposite exhibited prominent electrocatalytic behavior to simultaneously determine hydroquinone (HQ) and catechol (CC) in environmental waters. The as-prepared electrochemical sensor showed excellent performance towards the detection of HQ and CC with broad concentration ranges between 0.5–176.5 μM (HQ and CC), and the detection limits achieved were 0.063 μM (HQ) and 0.059 μM (CC). Furthermore, the developed modified electrode has exhibited excellent stability and reproducibility and was also applied to analyze HQ and CC in environmental water samples. Results revealed that chicken feather waste valorization could result in sustainable biomass conversion into a high-value nanomaterial to develop a cost-effective electrochemical environmental monitoring sensor and lipids for biofuel. [ABSTRACT FROM AUTHOR]

• The normally-off H-diamond MESFETs with a MoO 3 passivation layer were fabricated and the performances at different temperature were investigated. • The device can work normally at the temperature higher than 150 °C. • The MoO 3 passivated H-diamond FET shows great potential to be used in high temperature situation in the future. The normally-off hydrogen-terminated diamond metal–semiconductor field effect transistors (MESFETs) with a MoO 3 passivation layer were fabricated on the CVD grown polycrystalline diamond substrate. The characteristics of the device at room temperature and 100 °C, 150 °C and 200 °C were investigated. The device with a 2-μm gate shows a threshold voltage of −0.38 V, the maximum output current of 35 mA/mm and the transconductance of 17.4 mS/mm. The device can still work normally until 150 °C, which shows great potential to be used in high temperature in the future. [ABSTRACT FROM AUTHOR]

For Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells, eliminating multi-layer crystallization is a key issue of achieving high quality CZTSSe absorber layers and high cell performance. In this work, the formation mechanism of the multi-layer crystallization is revealed, that is, the reaction between CZTS and Mo may give the secondary phase, which subsequently acts as crystal nucleus to facilitate the CZTSSe crystal growth at back interface (Mo/CZTSSe), leading to multi-layer crystallization. By introducing MoO 3 isolating layer, this undesired reaction can be well prevented, and high quality single-layer crystals are obtained. This absorber film with fewer defects and secondary phases exhibits better semiconductor properties. Based on this regulated CZTSSe absorber layer, 11.68% (active area: 0.16092 cm2) and 10.69% (mask area: 0.17586 cm2) certified power-conversion-efficiency have been achieved with significant increase in the open-circuit voltage and fill factor. The origin of multi-layer crystallization of Cu 2 ZnSn(S,Se) 4 absorber layer is revealed for the first time. A simple, effective method is developed to eliminate this multi-layer crystallization to give high quality single-layer crystals, which exhibits 11.68% certified conversion efficiency of the device. Image 1 • Revealing formation mechanism of multi-layer crystallization for the first time. • Elimination of the multi-layer crystallization by introducing MoO 3 isolating layer. • As high as 11.68% certified power-conversion-efficiency has been achieved. [ABSTRACT FROM AUTHOR]