99 research outputs found
Long-lived photoinduced absorption in granular molybdenum disulfide thin films
Β© 2018 Institute of Physics Publishing. All rights reserved. We present results of the differential photoinduced absorption spectra investigation of the molybdenum disulfide nanogranular thin films. The films were produced by means of a sulfurization of pre-deposited by magnetron sputtering thin molybdenum films. It has been shown that photoexcitation with the light quanta with the energy higher than the bandgap leads to a modification of the absorption spectra in the visible range. Possible nature of the photoinduced absorption spectra will be discussed
Synthesis and properties of the molybdenum and tungsten disulfide thin films
Β© Published under licence by IOP Publishing Ltd.In the paper results of thin film synthesis and primary characterization of molybdenum and tungsten disulfides are presented. The synthesis is performed by means of the high-temperature sulfurization of the metallic Mo and W films in the flow of argon. Chemical and phase compositions and morphology of thin films are reported. Optical transmission and Raman spectra are presented and discussed
One-step synthesis of N-doped graphene in a plasma jet reactor
Β© Published under licence by IOP Publishing Ltd. The possibility of doping graphene during its synthesis in a plasma jet of nitrogen has been studied. Direct current plasma torch with power of up to 40 kW was used as plasma jet generator. The source of carbon was propane-butane mixture, acetylene or methane. Synthesized materials are characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. It has been shown that XPS spectra of graphene flakes produced in nitrogen plasma differ in atomic nitrogen content. The maximum degree of nitrogen doping of graphene was obtained at decomposition of acetylene at 77 Torr
Effect of irradiation by argon ions on hydrogen transport through the surface oxide layer of zirconium
Effect of zirconium irradiation by 1 keV Ar+ ions on hydrogen transport through the surface oxide layer is studied. It is shown that deuterium trapping under subsequent irradiation of the Ar-treated sample by deuterium atoms of thermal energies in D2 + 30at.% O2 gas mixture is 2 times less than trapping in the untreated sample. Besides, irradiation of the untreated sample by D-atoms provokes desorption of β25% of hydrogen contained therein, whereas hydrogen desorption from the ion-treated zirconium surface does not occur. It is proposed that oxygen depletion of the surface oxide layer, caused by ion bombardment, is a reason of mitigation of the hydrogen transport through this layer in both directions
Heterometallic complex formation on p-sulfonatothiacalix[4]arene platform resulting in pH- and redox-modification of [Ru(bpy)3]2+ luminescence
The pH-dependent heterometallic complex formation with p-sulfonatothiacalix[4]arene (TCAS) as bridging ligand in aqueous solutions was revealed by the use of spectrophotometry, nuclear magnetic relaxation and fluorimetry methods. The novelty of the structural motif presented is that the appendance of emission metal center ([Ru(bpy)3]2+) is achieved through the cooperative non-covalent interactions with the upper rim of TCAS. The second metal block (Fe(III), Fe(II) and Mn(II)), bound with the lower rim of TCAS in the inner sphere coordination mode is serving as quencher of [Ru(bpy)3]2+ emission. The difference between the complex ability of Fe(III) and Fe(II) ions provides pH conditions for redox-dependent emission of [Ru(bpy)3]2+. Β© 2009 Elsevier B.V. All rights reserved
Photophysical and electrochemical properties of the outer-sphere associate of [Ru(bipy)3]2+ with p-sulfonatothiacalix[4]arene
1H NMR titration and X-ray diffraction analysis revealed that [Ru(bipy)3]2+ forms an outer-sphere inclusion complex with p-sulfonatothiacalix[4]arene in a ratio of 1: 1 in both aqueous solutions and the solid state. According to cyclic voltammograms and fluorimetric data, the outer-sphere association of [Ru(bipy)3]2+ with p-sulfonatothiacalix[4]arene changes the reversible character of the electrochemical oxidation of [Ru(bipy)3]2+ and lowers its emission intensity. Β© 2008 Springer Science+Business Media, Inc
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