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231.
Titanium oxide nanoparticles were coated on multiwall carbon nanotubes (MWCNTs) using an atmospheric pressure chemical vapor
deposition (CVD) to achieve highly compact nanoparticles of about 5 nm on CNT structure. The CNTs with a diameter of about
50 nm were grown by plasma enhanced CVD. Gas sensitivity of the fabricated structure was investigated and compared with TiO2/CNT composite-based gas sensors. The effect of the structural interaction between the nanoparticles and the CNT wall on sensing
mechanism of the as-prepared gas sensors was investigated. Ultrasensitive gas sensors were obtained by TiO2/CNT nanostructures with strong interaction between the MWCNT and the TiO2 nanoparticles. The measurements show high chemical activity and exceptional electrical response of the as-prepared structure
being exposed to gases. Scanning and transmission electron microscopy and X-ray diffraction analysis were used to obtain structural
information. 相似文献
232.
R. I. Kureshy N. H. Khan S. H. R. Abdi S. T. Patel P. Iyer 《Journal of molecular catalysis. A, Chemical》1999,150(1-2):163-173
Ruthenium(II) chiral Schiff base complexes 1–10 and their precursor ligands derived from
-amino acids viz.
-leucine,
-histidine with salicylaldehyde, 3-tertiary-butyl-, 3,5-di-tertiary-butyl-, 3,5 dichloro- and 3,5-dinitrosalicylaldehyde are reported. The characterization of the ligands and complexes was accomplished by various appropriate physico-chemical studies, namely, microanalysis, IR-, UV/Vis-, 1H, 31P{1H} NMR, CD spectroscopy, optical rotation, conductance measurement and cyclic voltammetry. The complexes thus synthesised were used as catalysts for enantioselective epoxidation of 1,2-dihydronaphthalene. The effect on enantioselectivity and chemical conversions to epoxide were studied in different solvents viz. acetonitrile, dichloromethane and fluorobenzene along with change of the substituents on ligands and different terminal oxidants. The less polar nature of solvent as well as the donating group attached on the catalysts favours enantioselectivity, while PhIO was the oxidant of choice. The enantiomeric excess of the resulting epoxide was evaluated by chiral cyclodex BDA capillary column. 相似文献
233.