共查询到20条相似文献,搜索用时 15 毫秒
1.
A. Lakshmi Narayana M. Dhananjaya N. Guru Prakash O. M. Hussain C. M. Julien 《Ionics》2017,23(12):3419-3428
Nanocrystalline Li2TiO3 was successfully synthesized using solid-state reaction method. The microstructural and electrochemical properties of the prepared material are systematically characterized. The X-ray diffraction pattern of the prepared material exhibits predominant (002) orientation related to the monoclinic structure with C2/c space group. HRTEM images and SAED analysis reveal the well-developed nanostructured particles with average size of ~40 nm. The electrochemical properties of the prepared sample are carried out using cyclic voltammetry (CV) and chronopotentiometry (CP) using Pt//Li2TiO3 cell in 1 mol L?1 Li2SO4 aqueous electrolyte. The Li2TiO3 electrode exhibits a specific discharge capacity of 122 mAh g?1; it can be used as anode in Li battery within the potential window 0.0–1.0 V, while investigated as a supercapacitor electrode, it delivers a specific capacitance of 317 F g?1 at a current density of 1 mA g?1 within the potential range ?0.4 to +0.4 V. The demonstration of both anodic and supercapacitor behavior concludes that the nanocrystalline Li2TiO3 is a suitable electrode material for supercapattery application. 相似文献
2.
T. V. Sviridova L. Yu. Sadovskaya A. I. Kokorin E. A. Konstantinova V. E. Agabekov D. V. Sviridov 《Russian Journal of Physical Chemistry B, Focus on Physics》2017,11(2):348-353
The thin-film photocatalysts TiO2/MoO3 and TiO2/MoO3:V2O5 obtained by a combination of sol–gel and sintering techniques were studied using the photooxidation of probing dyes, EPR spectroscopy, X-ray diffraction analysis, and electron microscopy. It was shown that due to charge accumulation caused by UV irradiation, these photocatalysts retain their oxidative activity and ability for self-sterilization in the dark for a long time after irradiation was terminated (up to 5 h for TiO2/MoO3:V2O5). 相似文献
3.
Yong Liu Hongmei Xu Hai Wang Wenxia Zhao Chaolun Liang Minyi Zhong Hui Shen 《Applied Physics A: Materials Science & Processing》2011,102(1):127-130
Here we report on the growth of TiO2 nanotube arrays (TNAs) on Ti foil with laser-drilled microhole arrays (MHAs). The MHAs promoted the adhesion of the TNA film
to Ti substrate, which is well suited for flexible dye-sensitized solar cells (DSSCs). The MHA photoanode and TNAs were characterized
by SEM, 3D optical profiling, XRD and TEM. For such a flexible MHA photoanode, the TNA-based DSSC was assembled using a platinized
conductive glass counter electrode, and a conversion efficiency of 3.45% was achieved under AM 1.5 condition. A flexible TNA-based
DSSC was also fabricated using a flexible MHA photoanode combined with a platinized indium tin oxide-polyethylene naphthalate
counter electrode, which achieved 2.67% photovoltaic conversion efficiency under simulated AM 1.5 sunlight. 相似文献
4.
Two sets of samples of SnO2/In2O3/TiO2 system have been fabricated with different concentrations of component materials. In the first set TiO2 with rutile structure was used, while in the second set it has the structure of anatase. Thin films (up to 50 nm) of obtained
mixtures were deposited. Their sensitivity and selectivity with respect to methane (CH4) were studied. Nanostructure on the
basis of 70%SnO2 — 10%In2O3 — 20%TiO2(anatase) exhibits sufficient sensitivity to methane. 相似文献
5.
6.
Pure LiMn2O4 samples with high crystallinity (LMO-1# and LMO-2#) were successfully synthesized by a facile hydrothermal method using δ-MnO2 nanoflowers and α-MnO2 nanowires as the precursors. The as-prepared samples were analyzed by XRD, SEM, and Brunauer-Emmett-Teller (BET), and their capacitive properties were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge test. Two LiMn2O4 samples showed good capacitive behavior in aqueous hybrid supercapacitors. AC//LMO-1# and AC//LMO-2# delivered the initial specific capacitance of 45.4 and 40.7 F g?1 in 1 M Li2SO4 electrolyte at a current density of 200 mA g?1 in the potential range of 0~1.5 V, respectively. After 1000 cycles, the capacitance retention was 97.6% for AC//LMO-1# and 93.7% for AC//LMO-2#. Obviously, LMO-1# from δ-MnO2 nanoflowers exhibited higher specific capacitance and better cycling performance than LMO-2#, so LMO-1# was more suitable as the positive electrode material in hybrid supercapacitors. 相似文献
7.
Terry A. Egerton Lorna M. Kessell Ian R. Tooley Liwei Wang 《Journal of nanoparticle research》2007,9(2):251-260
Photogreying, the change in brightness on UV irradiation in the absence of oxygen, of TiO2 nanoparticulate dispersions is shown to depend on the nature of the liquid, consistent with a surface reaction. Measurements
on a series of TiO2 particles (mainly 75×10 nm) dispersed in, e.g., alkyl benzoate correlate well with those on the same TiO2’s dispersed in a second liquid (e.g. propan-2-ol). Photogreying in propan-2-ol is paralleled by photocatalytic-oxidation
activity, indicating a common origin – UV-generation of charge carriers. Further, photogreying parallels Ti3+ formation. Hence, although appearance and the visible spectra of photogreyed particles both differ from those of Ti3+ in ≤10 nm colloidal TiO2, we suggest that photogreying is caused by capture of UV excited electrons to form Ti3+. Surface treatment reduces photogreying, and we speculate that differences between uncoated samples reflect differences in
the number of potentially reducible Ti’s. 相似文献
8.
E. F. Sheka E. A. Nikitina V. A. Zayets I. Ya. Ginzburg J. Schoonman 《Physics of the Solid State》2007,49(1):154-163
We present the results of a quantum-chemical study of the interface formed by titania nanoparticles and a set of carboxylic
moieties, namely, benzoic and bi-isonicotinic acids and a tris-(2, 2′-dcbipyridine) Fe (II) complex placed on the surface
of either rutile or anatase polymorphs. The calculations were performed in the spd basis using semiempirical quantum-chemical codes, both sequential and parallel. The results are mainly addressed to the geometry
optimization of the adsorbed molecules on the surface, as well as to the adsorption mechanism and the energy of adsorption.
The text was submitted by the authors in English. 相似文献
9.
10.
N. I. Surovtseva N. P. Smirnova A. M. Eremenko T. V. Fesenko V. A. Pokrovsky 《Journal of Applied Spectroscopy》2010,77(2):202-205
Electronic spectroscopy and laser desorption/ionization (LDI) mass spectrometry have been used to study the effects of UV
exposure on acridine dyes such as acridine orange (AO) and acridine yellow (AY) adsorbed on the surface of mesoporous TiO2 films. The main stages of the photodegradation process have been identified. The first one is photooxidative N-demethylation
of the dimethylamino group in AO and deamination in AY. The following stages are photodimerization and photoaggregation on
the superhydrophilic TiO2 surface and further photocatalytic decomposition to the completely mineralized dyes. 相似文献
11.
Yu. P. Sukhorukov E. A. Gan’shina A. R. Kaul’ O. Yu. Gorbenko N. N. Loshkareva A. V. Telegin M. S. Kartavtseva A. N. Vinogradov 《Technical Physics》2008,53(6):716-721
Sm0.55Sr0.45MnO3/Nd0.55Sr0.45MnO3 heterostructure consisting of layers with different Curie temperatures is studied. By comparing data for IR transmission,
resistivity, magnetotransmission, magnetoresistance, and Kerr effect measured on the side of the film and substrate, the Curie
temperatures of the layers are determined and the contributions of the layers to the magnetoresistance and magnetotransmission
are estimated. A weak temperature dependence of the magnetotransmission and magnetoresistance makes manganites with a colossal
magnetoresistance and magnetotransmission candidate materials for devices without temperature stabilization. 相似文献
12.
E. G. Bagryanskaya O. A. Krumkacheva A. E. Belikov V. A. Mal’tsev S. A. Novopashin 《Journal of Engineering Thermophysics》2011,20(1):55-63
Measurements of proton nuclear spin-spin and spin-lattice relaxation times are applied for determining the concentration of
solid-phase nanoparticles in nanofluids. This approach is tested for metal oxides SiO2, TiO2, Al2O3 and metal-carbon nanoparticles of 3d-metals Fe and Cu. It is shown that the sensitivity of the method for determining concentrations
of 3d-metals is much higher than for oxides (by 2–4 orders of magnitude). It is revealed that measurement of the proton spin-spin
relaxation time allows one to determine the concentration of Cu nanoparticles to 0.0001 mg/ml and that of Fe nanoparticles
to 0.00001 mg/ml. 相似文献
13.
This paper reports an experimental study on the cryogenic phase change behaviour of liquid nitrogen upon injection into a
relatively large pool of aqueous based titanium dioxide nanofluids under ambient temperatures. Stable TiO2 are formulated at concentrations between 1% and 4% by particle weight, and characterized in the experiments. Both transient
pressure and temperature profiles are measured and analysed in the range of liquid nitrogen Reynolds number of 2,200–11,000
and Webber number of 9–220. The results, however, do not show obvious influence of nanoparticles’ concentration on the pressure
build up and heat transfer under the condition of this work. Very similar results are observed for liquid nitrogen injection
into pure distilled water and into different concentrations of TiO2 nanofluids; both the pressure and the rate of pressure rise during the injection process increase linearly with injection
velocity irrespective of nanoparticle concentrations. Further discussion shows that a higher rate of pressure rise could be
achieved if operating conditions were optimised to induce the fragmentation and subsequent vapour explosion. 相似文献
14.
A novel approach of double hydroxide-mediated synthesis of nickel cobaltite (NiCo2O4) electro-active material by the hydrothermal method is reported. The obtained NiCo2O4 electro-active material displays the spinel cubic phase and hexagonal-like morphology. Thermogravimetry analysis confirms the thermal stability of the electrode material. The functional groups and phase formation of NiCo2O4 have been confirmed by FT-IR and Raman spectral analysis. The modified NiCo2O4 electrode exhibits the highest specific capacitance of 767.5 F g?1 at a current density of 0.5 A g?1 in 3 M KOH electrolyte and excellent cyclic stability (94 % capacitance retention after 1000 cycles at a high current density of 5 A g?1). The excellent electrochemical performance of the electrode is attributed to the hexagonal-like morphology, which contributes to the rich surface electro-active sites and easy transport pathway for the ions during the electrochemical reaction. The attractive Faradic behavior of NiCo2O4 electrode has been ascribed to the redox contribution of Ni2+/Ni3+ and Co2+/Co3+ metal species in the alkaline medium. The symmetrical two-electrode cell has been fabricated using the NiCo2O4 electro-active material with excellent electrochemical properties for supercapacitor applications. 相似文献
15.
Single crystals of Eu0.62Bi0.38MnO3 and Eu0.53Bi0.32Sr0.15MnO3 solid solutions crystallizing in an orthorhombically distorted perovskite structure were prepared. At temperatures above 120 K, Eu0.62Bi0.38MnO3 exhibits the properties of structural glass while remaining a dielectric at all temperatures. There is no long-range magnetic order in this compound. Eu0.53Bi0.32Sr0.15MnO3 behaves as a semiconductor above 120 K and exhibits a jump in conductivity at T = 175 K associated with a metal-insulator transition occurring within limited regions of the crystal. In these regions, there appears a ferromagnetic moment (due to double exchange mediated by charge carriers) and local electric polarization. 相似文献
16.
Yu. P. Sukhorukov A. V. Telegin E. A. Gan’shina E. A. Stepantsov A. N. Vinogradov F. Lombardi D. Winkler 《Technical Physics》2010,55(8):1161-1167
The optical, magnetooptical (Kerr effect and magnetotransmission), and magnetotransport properties of La2/3Ca1/3MnO3/La2/3Sr1/3MnO3 and La2/3Ca1/3MnO3/SrTiO3/La2/3Sr1/3MnO3 heterostructures on SrTiO3 substrates are studied. The contribution of the interface boundary to the magnetotransmission is typical of a material with
a transitional composition. It is found that a 2-nm-thick SrTiO3 spacer does not influence the shape and position of the magnetotransmission peak in a field normal to the surface of the
heterostructure but increases the contribution of the upper layer to the magnetotransmission in the Voigt geometry and also
enhances the magnetoresistance that is due to the tunneling of spin-polarized carriers through the spacer. The Kerr spectra
taken of the heterostructures are typical of single-layer single-crystal films. 相似文献
17.
A. V. Telegin M. S. Kartavtseva Yu. P. Sukhorukov E. A. Gan’shina A. R. Kaul’ O. Yu. Gorbenko S. N. Tugushev A. N. Vinogradov 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(11):1584-1585
The effects of magnetotransmission and magnetoresistance in a film heterostructure composed of manganite layers with different Curie temperatures have been analyzed. High sensitivity of optical methods to the presence of different magnetic phases in the bulk of the material has been shown. 相似文献
18.
Mohamed Kamal Ahmed Ali Hou Xianjun Ahmed Elagouz F.A. Essa Mohamed A. A. Abdelkareem 《Journal of nanoparticle research》2016,18(12):377
Minimizing of the boundary friction coefficient is critical for engine efficiency improvement. It is known that the tribological behavior has a major role in controlling the performance of automotive engines in terms of the fuel consumption. The purpose of this research is an experimental study to minimize the boundary friction coefficient via nano-lubricant additives. The tribological characteristics of Al2O3 and TiO2 nano-lubricants were evaluated under reciprocating test conditions to simulate a piston ring/cylinder liner interface in automotive engines. The nanoparticles were suspended in a commercially available lubricant in a concentration of 0.25 wt.% to formulate the nano-lubricants. The Al2O3 and TiO2 nanoparticles had sizes of 8–12 and 10 nm, respectively. The experimental results have shown that the boundary friction coefficient reduced by 35–51% near the top and bottom dead center of the stroke (TDC and BDC) for the Al2O3 and TiO2 nano-lubricants, respectively. The anti-wear mechanism was generated via the formation of protective films on the worn surfaces of the ring and liner. These results will be a promising approach for improving fuel economy in automotive. 相似文献
19.
The manganese oxide/multi-walled carbon nanotube (MnO2/MWNT) composite and the manganese oxide/acetylene black (MnO2/AB) composite were prepared by translating potassium permanganate into MnO2 which formed the above composite with residual carbon material using the redox deposition method and carbon as a reducer.
The products were characterized by X-ray diffraction, Fourier transform infrared, and scanning electron microscope. Electrochemical
properties of both the MnO2/MWNT and MnO2/AB electrodes were studied by using cyclic voltammetry, electrochemical impedance measurement, and galvanostatic charge/discharge
tests. The results show that the MnO2/MWNT electrode has better electrochemical capacitance performance than the MnO2/AB electrode. The charge–discharge test showed the specific capacitance of 182.3 F·g−1 for the MnO2/MWNT electrode, and the specific capacitance of 127.2 F·g−1 for the MnO2/AB electrode had obtained, within potential range of 0–1 V at a charge/discharge current density of 200 mA·g−1 in 0.5 mol·L−1 potassium sulfate electrolyte solution in the first cycle. The specific capacitance of both the MnO2/MWNT and MnO2/AB electrodes were 141.2 F·g−1 and 78.5 F·g−1 after 1,200 cycles, respectively. The MnO2/MWNT electrode has better cycling performance. The effect of different morphologies was investigated for both MnO2/MWNT and MnO2/AB composites. 相似文献