نتایج جستجو برای: keywords vanadium oxide nanotubes vonts

تعداد نتایج: 2168623  

Journal: :Journal of the American Chemical Society 2008
Feng Dong Scott Heinbuch Yan Xie Jorge J Rocca Elliot R Bernstein Zhe-Chen Wang Ke Deng Sheng-Gui He

Reactions of neutral vanadium oxide clusters with small hydrocarbons, namely C2H6, C2H4, and C2H2, are investigated by experiment and density functional theory (DFT) calculations. Single photon ionization through extreme ultraviolet (EUV, 46.9 nm, 26.5 eV) and vacuum ultraviolet (VUV, 118 nm, 10.5 eV) lasers is used to detect neutral cluster distributions and reaction products. The most stable ...

2002
Israel E. WACHS Jih-Mirn JEHNG D. HARDCASTLE

The interaction of vanadium oxide and niobium oxide with A1203 and TiO2 supports is examined with Raman spectroscopy. The Raman spectra of the supported metal oxides reveal that the strong interaction of the metal oxides with AI203 and TiO2 supports results in the formation of two-dimensional surface metal oxide overlayers. The surface vanadium oxide overlayers are unstable to high calcination ...

Journal: :Fizika tverdogo tela 2022

The formation of nanosized catalyst particles for the growth carbon nanotubes can be carried out during crystallization amorphous films consisting two metals, one which has higher free energy oxide. During annealing in presence oxygen, this metal is oxidized with reduction second metal, leads to nanoparticles embedded oxide first metal. This process been experimentally and theoretically studied...

Journal: :iranian journal of biotechnology 2007
hossein salehizadeh marzieh mousavi sadegh hatamipour kasra kermanshahi

an isolate from polluted soil identified as aspergillus sp. ms-100 was able to consume vanadium oxide octaethyl porphyrin as a model for protoporphyrins in crude oil. the isolate degrades about 55% of vanadium oxide octaethyl porphyrin (vooep) under optimum conditions during 7 days. the release of more than 0.96 mgl-1 of free vanadium into the aqueous phase was confirmed using atomic absorption...

2009
Hongfang Shen Qing Guo Zhiman Zhao Guozhong Cao

The present research investigated the sol–gel preparation, dielectric and ferroelectric properties of PZT films doped with 5 mol% vanadium oxide. Stable PZTV sols can be readily formed, and homogeneous, micrometer thick and pinhole-free PZTV films were obtained by using spin coating followed with rapid annealing. The X-ray diffraction patterns revealed that no parasitic or secondary phases were...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2010
ahmad tavasoli sanaz anahid ali nakhaeipour

the effects of confinement in carbon nanotubes on fischer-tropsch (ft) activity, selectivity and lifetime of carbon nanotubes (cnts) supported iron catalysts are reported. a method was developed to control the position of the catalytic sites on either inner or outer surface of carbon nanotubes. tem analyses revealed that more than 80% of iron oxide particles can be controlled to be positioned a...

2007
C. Hess

Raman, UV-Vis and X-ray photoelectron spectroscopy were combined in one experimental setup to directly study the interplay between structure and dispersion of SBA-15 supported vanadium oxide during dehydration. The fully hydrated catalyst is slightly reduced but consists mainly of V species with pseudo-octahedral V coordination strongly resembling the xerogel V2O5·1.2H2O. After dehydration a hi...

2006
S. Guimond M. Abu Haija S. Kaya J. Lu J. Weissenrieder S. Shaikhutdinov H. Kuhlenbeck H.-J. Freund J. Döbler J. Sauer

The information obtained from the characterization of vanadium oxide single crystal surfaces is related to the study of vanadia nanoparticles supported on silica and alumina thin films, model systems for the so-called ‘‘supported monolayer vanadia catalysts’’. It is found that these particles have properties similar to V2O3 surfaces, where the topmost V ions are involved in vanadyl groups and h...

2013
Juan M. Salazar

Vanadium phosphorous oxide (VPO) is traditionally manufactured from solid vanadium oxides by synthesizing VOHPO4·0.5H2O (the precursor) followed by in situ activation to produce (VO)2P2O7 (the active phase). This paper discusses an alternative synthesis method based on sol-gel techniques. Vanadium (V) triisopropoxide oxide was reacted with ortho-phosphoric acid in an aprotic solvent. The produc...

Journal: :ACS applied materials & interfaces 2011
Changhyun Ko Zheng Yang Shriram Ramanathan

Vanadium dioxide (VO(2)) undergoes a sharp metal-insulator transition (MIT) in the vicinity of room temperature and there is great interest in exploiting this effect in novel electronic and photonic devices. We have measured the work function of vanadium dioxide thin films across the phase transition using variable temperature Kelvin force microscopy (KFM). The work function is estimated to be ...

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