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1.
Fattakhova Rohlfing D Rathouský J Rohlfing Y Bartels O Wark M 《Langmuir : the ACS journal of surfaces and colloids》2005,21(24):11320-11329
Mesoporous silica thin films were shown to be an appropriate matrix for immobilization of discrete electroactive moieties, yielding uniform transparent thin film electrodes with defined texture and enhanced electrochemical activity. The mesoporous silica films prepared on conducting FTO-coated glass substrate were postsynthetically functionalized. Alkoxysilanes were used as precursors for subsequent grafting via ionic or covalent bonds of representative electroactive species, such as polyoxometalate PMo12O(40)3-, hexacyanoferrate(III), and ferrocene. The electrochemically active concentration within the silica-based composite electrodes achieves 90, 260, and 60 micromol cm(-3) for polyoxometalate, hexacyanoferrate(III), and ferrocene, respectively. The amount of molecules involved in the charge-transfer sequence is proportional to the film thickness and comparable to the total amount of embedded guests. Thus, eventually the whole bulk volume of the modified silica films is electrochemically accessible. Immobilization in the chemically modified silica matrix alters the redox potential of the electroactive molecules. Electron exchange between the adjacent redox centers (electron hopping) is proposed as a possible charge propagation pathway through the insulating silica matrix, which is supported by the fact that the high charge uptake is observed also for the hybrid electrodes with the covalently anchored redox guests. 相似文献
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D. N. Vtyurina A. N. Romanov K. S. Zaramenskikh M. N. Vasil’eva Z. T. Fattakhova L. A. Trusov P. A. Loiko V. N. Korchak 《Russian Journal of Physical Chemistry B, Focus on Physics》2016,10(2):211-214
The properties of bismuth-containing luminescent materials prepared by impregnating a porous glass with an aqueous solution of bismuth and aluminum salts followed by thermal treatment are studied. The formation of a variety of bismuth-containing centers luminescent in the near infrared range of the spectrum is revealed, one of which is the Bi+ monocation. At high temperatures, along with it, bismuth-containing cluster-type luminescent centers are apparently formed. 相似文献
4.
Il’ichev A. N. Bykhovsky M. Ya. Fattakhova Z. T. Shashkin D. P. Korchak V. N. 《Kinetics and Catalysis》2022,63(5):505-514
Kinetics and Catalysis - Samples of (0.5–15)%CoO/CeO2, Co3O4, and CeO2 have been studied in the oxidation of CO to CO2 in a CO+O2+H2 mixture in a range of 40–340°C. The highest... 相似文献
5.
N. Il’ichev Z. T. Fattakhova D. L. Shashkin V. A. Matyshak V. N. Korchak 《Kinetics and Catalysis》2016,57(5):686-696
The CO adsorption species on Co3O4 and (0.5-15%)CoO/CeO2 catalysts have been investigated by temperature-programmed desorption and IR spectroscopy. At 20°C, the largest amount of CO is adsorbed on the 5%CoO/CeO2 sample to form, on Com2+On2+ clusters, hydrogen-containing, bidentate, and monodentate carbonate complexes, whose decomposition is accompanied by CO2 desorption at 300 and 450°C (1.1 × 1020 g–1). The formation of the carbonates is accompanied by the formation of Co+ cations and Co0, on which carbonyls form. The latter decompose at 20, 90, and 170°C to release CO (2.7 × 1019 g–1). Part of the carbonyls oxidizes to CO2 upon oxygen adsorption, and the CO2 undergoes desorption at 20°C. Adsorbed oxygen decreases the decomposition temperature of the H-containing and bidentate carbonates from 300 to 100-170°C and maintains the sample in the oxidized state, which is active in subsequent CO adsorption and oxidation. CO oxidation by oxygen of the catalyst diminishes the activity of the sample in these processes and increases the decomposition temperature of the carbonate complexes. Taking into account the properties of the adsorption complexes, we concluded that the H-containing and bidentate carbonates are involved in CO oxidation by oxygen of the catalyst at ~170°C under isothermal conditions. The rate limiting step is the decomposition of the carbonates, a process whose activation energy is 65-74 kJ/mol. 相似文献
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Lithium insertion into titanium dioxide (anatase) electrodes: microstructure and electrolyte effects
Dina Fattakhova Ladislav Kavan Petr Krtil 《Journal of Solid State Electrochemistry》2001,5(3):196-204
Insertion characteristics of anatase electrodes were studied on single-crystal and polycrystalline electrodes of different
microstructures. The lithium incorporation from propylene carbonate solution containing LiClO4 and Li(CF3SO2)2N was studied by means of cyclic voltammetry (CV), the quartz crystal microbalance (QCM) and the galvanostatic intermittent
titration technique (GITT). The electrode microstructure affects both the accessible coefficient x and the reversibility of the process. The highest insertion activity was observed for electrodes composed of crystals with
characteristic dimensions of ∼10–8 m. The insertion properties deteriorate for higher as well as for smaller crystal sizes. Enhanced insertion was observed in
Li(CF3SO2)2N-containing solutions. Lithium insertion is satisfactorily reversible for mesoscopic electrodes; the reversibility in the
case of compact polycrystalline and single-crystal electrodes is poor. The reversibility of the insertion improves with increasing
electrolyte concentration. The lithium diffusion coefficient decreases with increasing x and ranges between 10–15 and 10–18 cm2 s–1.
Electronic Publication 相似文献
7.
A. A. Veber A. N. Romanov O. V. Usovich Z. T. Fattakhova E. V. Haula V. N. Korchak L. A. Trusov P. E. Kazin V. B. Sulimov V. B. Tsvetkov 《Applied physics. B, Lasers and optics》2012,108(4):733-736
We observed a high strength near-infrared luminescence in Bi-doped KAlCl4 polycrystalline material. Luminescence dependence on the excitation wavelength and temperature of the sample was studied. Our experimental results allow asserting that the luminescence peaked near 1?μm belongs solely to Bi+ ion which isomorphically substitutes potassium in the crystal. It was also demonstrated that Bi+ luminescence features strongly depend on the local ion surroundings. 相似文献
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Petr Krtil Dina Fattakhova Masahiro Yoshimura 《Journal of Solid State Electrochemistry》2002,6(6):367-373
The mechanism of alkaline earth metal tungstate formation during soft solution processing was studied by cyclic voltammetry,
electrochemical impedance spectroscopy and by direct in situ observation of the surface changes using atomic force microscopy.
The electrochemical oxidation of W to WO3 was followed by dissolution of WO3 and, with some delay, by precipitation of tungstates at the metal surface. The same Tafel slopes observed in Li+, Ba2+, Sr2+ and Ca2+ containing solutions indicate that the course of the oxidation process is independent of the cation present in solution. The
observed differences in the current-voltage curves outside the Tafel region are accounted for by the different film-forming
tendencies of the various alkaline earth metal cations. The growth of tungstate layers at the W substrate decreases the electrochemically
active area and limits the production of WO4
2– at later stages of deposition. At low potentials (E<0.2 V) the oxidation of W is the rate-controlling step. At higher potentials, however, the dissolution process slows down
due to a relative decrease of the pH in the electrode vicinity and dissolution becomes the rate-limiting step.
Electronic Publication 相似文献
9.
D. N. Vtyurina A. N. Romanov M. S. Kuznetsov Z. T. Fattakhova E. V. Khaula I. S. Lisitskii V. N. Korchak 《Russian Journal of Physical Chemistry B, Focus on Physics》2016,10(1):1-4
IR photoluminescence of bismuth-doped ternary thallium chloride TlCdCl3 was studied. Two bismuth-containing luminescence impurity centers were detected. One of these was found to be the bismuth Bi+ monocation, emitting at 1025 nm. 相似文献
10.
Zintl Clusters as Wet‐Chemical Precursors for Germanium Nanomorphologies with Tunable Composition 下载免费PDF全文
Manuel M. Bentlohner Dr. Markus Waibel Patrick Zeller Dr. Kuhu Sarkar Prof. Dr. Peter Müller‐Buschbaum Priv.‐Doz. Dr. Dina Fattakhova‐Rohlfing Prof. Dr. Thomas F. Fässler 《Angewandte Chemie (International ed. in English)》2016,55(7):2441-2445
[Ge9]4? Zintl clusters are used as soluble germanium source for a bottom–up fabrication of Ge nanomorphologies such as inverse opal structures with tunable composition. The method is based on the assembly and oxidation of [Ge9]4? clusters in a template mold using SiCl4, GeCl4, and PCl3 leading to Si and P‐containing Ge phases as shown by X‐ray diffraction, Raman spectroscopy, and energy‐dispersive X‐ray analysis. [Ge9]4? clusters are retained using ethylenediamine (en) as a transfer medium to a mold after removal of the solvent if water is thoroughly excluded, but are oxidized to amorphous Ge in presence of water traces. 1H NMR spectroscopy reveals the oxidative deprotonation of en by [Ge9]4?. Subsequent annealing leads to crystalline Ge. As an example for wet‐chemical synthesis of complex Ge nanomorphologies, we describe the fabrication of undoped and P‐doped inverse opal‐structured Ge films with a rather low oxygen contents. The morphology of the films with regular volume porosity is characterized by SEM, TEM, and grazing incidence small‐angle X‐ray scattering. 相似文献