• Title/Summary/Keyword: Molybdenum (Mo)

Search Result 463, Processing Time 0.026 seconds

A New Way to Prepare MoO3/C as Anode of Lithium ion Battery for Enhancing the Electrochemical Performance at Room Temperature

  • Yu, Zhian;Jiang, Hongying;Gu, Dawei;Li, Jishu;Wang, Lei;Shen, Linjiang
    • Journal of Electrochemical Science and Technology
    • /
    • v.7 no.2
    • /
    • pp.170-178
    • /
    • 2016
  • Composited molybdenum oxide and amorphous carbon (MoO3/C) as anode material for lithium ion batteries has been successfully synthesized by calcining polyaniline (PANI) doped with ammonium heptamolybdate tetrahydrate (AMo). The as prepared electrode material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). The electrochemical performance of the anode was investigated by galvanostatic charge/discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The MoO3/C shows higher specific capacity, better cyclic performance and rate performance than pristine MoO3 at room temperature. The electrochemical of MoO3/C properties at various temperatures were also investigated. At elevated temperature, MoO3/C exhibited higher specific capacity but suffered rapidly declines. While at low temperature, the electrochemical performance was mainly limited by the low kinetics of lithium ion diffusion and the high charge transfer resistance.

Synthesis and Characterization of Molybdenum Complexes with Schiff Bases (I). Bis-(N-aryl salicylaldiminato) of dioxomolybdenum (VI) Complexes (몰리브덴의 시프-염기착물의 합성과 그 성질 (제1보). 다이옥소 몰리브데늄(VI)의 아릴살릴실알디미나토착물)

  • Oh Sang Oh;Bon Kweon Koo
    • Journal of the Korean Chemical Society
    • /
    • v.29 no.3
    • /
    • pp.226-232
    • /
    • 1985
  • Dioxomolybdenum(VI) complexes, MoO$_2$(H-Sal-R)$_2$, R; arylamines, have been synthesized by reactions of dioxobis (salicylaldehydato) molybdenum(VI) with various primary amines. These complexes have been characterized by electric conductivity and spectroscopic studies. Infrared, uv-vis, and proton nmr spectra show that the complexes are six-coordinated with cis-MoO$_2$ group. And mass spectra indicates that the combining ratios for Mo (VI)-ligand are 1 : 2. They are yellow, stable for a considerably long time in the atmosphere at room temperature and slightly soluble in alcohol, dichloromethane and dimethylformamide but insoluble in benzene, ether and carbon tetrachloride.

  • PDF

Physicochemical Characterization of Mo Films at Various Oxygen Ratio

  • Bin, Jun-Hyeong;Park, Ju-Yeon;Gang, Yong-Cheol
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.08a
    • /
    • pp.88-88
    • /
    • 2010
  • We synthesized molybdenum thin films deposited by RF magnetron sputtering and physicochemical analysis was performed. The physical and chemical properties of these films were examined with X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The obtained film at the oxygen ratio of 0% showed crystallinity of cubic Mo(110) phase. After the oxygen ratio increased more than 5% in the sputter gas, the molybdenum films were formed as an amorphous phase. The thickness of the Mo thin film was drastically decreased from 1000 nm to ca 70 nm after introduction of oxygen in the sputter gas confirmed by spectroscopic ellipsometer (SE) and scanning electron spectroscopy (SEM). The calculated band gap of the film deduced from SE data increased from 3.17 to 3.63 eV by addition of oxygen in the sputter gas. The roughness of the Mo film was examined with atomic force microscopy (AFM) and it was dramatically decreased by introducing of oxygen during sputtering. XPS results revealed that the ratio of metallic Mo species in the film decreased by the contents of Mo(VI) species increased at the ratio of oxygen increased in the sputter gas and fully oxidized at low content of oxygen in the sputter gas.

  • PDF

Conceptual design of hybrid target for molybdenum-99 production based on heavywater

  • Ali Torkamani ;Ali Taghibi Khotbehsara ;Faezeh Rahmani ;Alexander Khelvas ;Alexander Bugaev ;Farshad Ghasemi
    • Nuclear Engineering and Technology
    • /
    • v.55 no.5
    • /
    • pp.1863-1870
    • /
    • 2023
  • Molybdenum-99 (99Mo) is used for preparing Technetium-99 m (99mTc), which is the most widely used isotope in nuclear medicine. In this work, a study for 99Mo production based on a high-power electron accelerator has been performed as an alternative approach to produce 99mTc. In this study, Monte Carlo MCNPX2.6 code has been used to examine a novel idea of simultaneous hybrid production of 99Mo via both photoneutron and neutron capture reactions using an electron accelerator in heavy water tank. It is expected that this conceptual design including an arrangement of metallic plates of 100Mo and 98Mo produces total activity of 97.5 Ci at the end of 20-h continuous e-beam irradiation (30 MeV, 10 mA).

Activity and Selectivity in Low Temperature for Dibenzothiophene Hydrodesulfurization based Zeolite Support (제올라이트 담체상의 디벤조티오펜 수첨탈황반응에서 저온활성 및 선택성)

  • Kim, Moon-Chan
    • Applied Chemistry for Engineering
    • /
    • v.9 no.1
    • /
    • pp.101-106
    • /
    • 1998
  • Two types of CoMo/zeolite as well as $NiMo/{\gamma}-Al_2O_3$ were prepared and their activities and selectivities of low-temperature dibenzothiophene(DBT) hydrodesulfurization(HDS) were studied in high pressure fixed bed reactor. The HDS activities of CoMo/zeolites were higher than that of $NiMo/{\gamma}-Al_2O_3$ at temperatures below $225^{\circ}C$ while they were lower than that of $NiMo/{\gamma}-Al_2O_3$ at temperatures higher than $275^{\circ}C$. The main products from $NiMo/{\gamma}-Al_2O_3$ were biphenyl and cyclohexylbenzene. The product distribution of CoMo/zeolite catalysts was different from that of $NiMo/{\gamma}-Al_2O_3$. It is speculated that DBT is converted to alkylcyclohexane over zeolite based catalysts through both alkylation and hydrogenation reactions. The crystal structure of molybdenum was $MoO_3$ in fresh zeolite support while mixtures of $MoO_3$ and $MoS_2$ were observed in the aged catalyst.

  • PDF

Effect of Metal Barrier Layer for Flexible Solar Cell Devices on Tainless Steel Substrates

  • Kim, Kyoung-Bo
    • Applied Science and Convergence Technology
    • /
    • v.26 no.1
    • /
    • pp.16-19
    • /
    • 2017
  • A thin metal layer of molybdenum is placed between the conventional barrier layer and the stainless steel substrate for investigating the diffusion property of iron (Fe) atoms. In this study, the protection probability was confirmed by measuring the concentration of out-diffused Fe using a SIMS depth profile. The Fe concentration of chromium (Cr) barrier layer with 10 nm molybdenum (Mo) layer is 5 times lower than that of Cr barrier without the thin Mo layer. The insertion of a thin Mo metal layer between the barrier layer and the stainless steel substrate effectively protects the out-diffusion of Fe atoms.

High temperature poly-Si thin film transistors on a molybdenum substrate

  • Kim, Do-Young;Gangopadhyay, Utpal;Park, Joong-Hyun;Ko, Jae-Kyung;Yi, Jun-Sin
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.523-525
    • /
    • 2002
  • The poly-Si thin film can be used in high mobility active matrix liquid-crystal display (AMLCD) and system on panel (SOP). In this paper, poly-Si thin films were grown by novel high temperature process on the molybdenum (Mo) substrate. By applying a high current above 48A on a Mo substrate. We obtained an improved crystalline Si films with the crystallinity over 80%. We exhibit the properties of structural and electrical properties of high temperature poly-Si thin film transistor on the Mo substrates.

  • PDF

Phase Transformation by the Oxidation of Air-passivated W and Mo Nanopowders Produced by an Electrical Explosion of Wires

  • Kwon, Young-Soon;Kim, Ji-Soon;A. Gromov, Alexander;Hong, Moon-Hee
    • Journal of Powder Materials
    • /
    • v.11 no.2
    • /
    • pp.130-136
    • /
    • 2004
  • The passivation and oxidation process of tungsten and molybdenum narlopowders, produced by electrical explosion of wires was studied by means of FE-SEM, XPS. XRD, TEM, DIA-TGA and sire distribution analysis. In addition, the phase transformation of W and Mo nanopowders under oxidation in air was investigated. A chemical process is suggested for the oxidation of W and Mo nano-particles after a comprehensive testing of passivated and oxidized powders.

Electrochemical Multi-Coloration of Molybdenum Oxide Bronzes

  • Lee, Sang-Min;Saji, Viswanathan S.;Lee, Chi-Woo
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.8
    • /
    • pp.2348-2352
    • /
    • 2013
  • We report a simple electrochemical approach in fabricating multiple colored molybdenum (Mo) oxide bronzes on the surface of a Mo-quartz electrode. A three step electrochemical batch process consisting of linear sweep voltammetry and anodic oxidation followed by cathodic reduction in neutral $K_2SO_4$ electrolyte at different end potentials, viz. -0.62, -0.80 and -1.60 V (vs. $Hg/HgSO_4$) yielded red, blue and yellow colored bronzes. The samples produced were analyzed by XRD, EDS, and SIMS. The color variation was suggested to be associated with the cations intercalation into the oxide formed and the simultaneous structural changes that occurred during the cathodic reduction in neutral aqueous medium.

XPS Study of MoO3 Interlayer Between Aluminum Electrode and Inkjet-Printed Zinc Tin Oxide for Thin-Film Transistor

  • Choi, Woon-Seop
    • Transactions on Electrical and Electronic Materials
    • /
    • v.12 no.6
    • /
    • pp.267-270
    • /
    • 2011
  • In the process of inkjet-printed zinc tin oxide thin-film transistor, the effect of metallic interlayer underneath of source and drain electrode was investigated. The reason for the improved electrical properties with thin molybdenum oxide ($MoO_3$) layer was due to the chemically intermixed state of metallic interlayer, aluminum source and drain, and oxide semiconductor together. The atomic configuration of three Mo $3d_3$ and $3d_5$ doublets, three different Al 2p core levels, two Sn $3d_5$, and four different types of oxygen O 1s in the interfaces among those layers was confirmed by X-ray photospectroscopy.