排序方式: 共有36条查询结果,搜索用时 23 毫秒
1.
Mustafa Aghazadeh Mehdi Ghaemi Behrouz Sabour Somayeh Dalvand 《Journal of Solid State Electrochemistry》2014,18(6):1569-1584
Well-dispersed nanoparticles of nickel hydroxide were prepared via a simple electrochemical method. Electrodeposition experiments were performed from 0.005 M Ni(NO3)2 bath at a constant current density of 0.1 mA cm?2 on the steel cathode for 1 h. Recording the potential values during the deposition process revealed that the reduction of water has major role in the base electrogeneration at the applied conditions. The obtained deposit was characterized by the X-ray diffraction (XRD), infrared (IR), differential scanning calorimeter–thermogravimetric analysis, carbon–nitrogen–hydrogen (CHN), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The CHN, XRD, and IR analyses showed that the obtained deposit has α phase of Ni(OH)2 with intercalated nitrate ions in its structure. Morphological characterization by SEM and TEM revealed that the prepared α-Ni(OH)2 is composed of well-dispersed ultrafine particles with the size of about 5 nm. The supercapacitive performance of the prepared nanoparticles was analyzed by means of cyclic voltammetry and galvanostatic charge–discharge tests. The electrochemical measurements showed an excellent supercapacitive behavior of the prepared α-Ni(OH)2 nanoparticles. It was also observed that the α-Ni(OH)2 ultrafine particles have better electrochemical characteristic and supercapacitive behavior than β-Ni(OH)2 ultrafine nanoparticles, including less positive charging potential, lower E a???E c value, better reversibility, higher E OER???E a, higher utilization of active material, higher proton diffusion coefficient, greater discharge capacity, and better cyclability. These results make the α-Ni(OH)2 nanoparticles as an excellent candidate for the supercapacitor materials. 相似文献
2.
Research on Chemical Intermediates - A highly efficient magnetic adsorbent is presented to preconcentrate acid violet-7 (AV-7) prior quantifying by UV–visible spectroscopy... 相似文献
3.
Cadmium sulfide (CdS) with different morphologies was successfully prepared by solvothermal process by controlling the processing
parameters, including nature of precursor and solvent, reaction temperature and process time. X-ray diffraction patterns revealed
that, in all cases highly pure and crystallized CdS with hexagonal structure were obtained. In addition, it was found that
the processing parameters influence on preferable growth direction of CdS nanostructures. Field emission scanning electron
microscope analysis showed that CdS nanowires with different aspect ratios were obtained (depending upon the reaction temperature
and process time) in presence of sulfur powder and ethylenediamine, whereas CdS nanoparticles were produced by sulfur powder
and ethanolamine. Moreover, CdS nanorods were prepared using thiourea and ethylenediamine. Transmission electron microscope
image confirmed that CdS nanowire with one of the highest aspect ratio reported in the literature (i.e., 255) was achieved
using sulfur powder and ethylenediamine at 200 °C reaction temperature for 72 h process time. UV–Vis absorption spectra of
CdS nanostructures prepared under different conditions displayed a blue shift relative to that of bulk CdS due to the quantum
size effect. 相似文献
4.
Aliyari Elnaz Fathi Ali Akbar Alvand Mahrouz Jamshidi Parastoo Shemirani Farzaneh Mozaffari Shahla Neyestani Mahmoud Reza 《Research on Chemical Intermediates》2021,47(5):1905-1918
Research on Chemical Intermediates - This article presents an ultrasound-assisted dispersive magnetic solid-phase extraction method (USA-DMSPE) to preconcentration Cd(II) and Pb(II) simultaneously.... 相似文献
5.
The orthometalated complex [Pd(μ-Cl)(C6H5C6H4C(O)CHPPh2C6H4-κ2-C,C)]2 (1) was prepared by refluxing in MeOH/CH2Cl2 equimolecular amounts of Pd(OAc)2 and (Ph)3PCHCOC6H4-Ph-4 (=PhBPPY) followed by addition of excess NaCl. Complex 1 reacts with 4-picoline to give the mononuclear derivative [Pd(PhC6H4COCHPPh2C6H4)(4-picoline)] (2) whose crystal structure has been determined by X-ray diffraction. The precursor complex (1) could not be isolated in a pure form, but it can be used as a starting material for the synthesis of derivatives of mononuclear
cyclo-palladated complexes. Orthometallation and ylide C-coordination in complexes 3–5 were characterized by elemental analysis as well as various spectroscopic techniques. 相似文献
6.
In this paper, we study generalized symmetric Finsler spaces. We first study some existence theorems, then we consider their
geometric properties and prove that any such space can be written as a coset space of a Lie group with an invariant Finsler
metric. Finally we show that each generalized symmetric Finsler space is of finite order and those of even order reduce to
symmetric Finsler spaces and hence are Berwaldian. 相似文献
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Parastoo Jamshidi Masoud Salavati-Niasari Davood Ghanbari Hamid Reza Shams 《Journal of Cluster Science》2013,24(4):1151-1162
Uniform CeO2 nanoparticles were synthesized via a facile sonochemical reaction between ceric ammonium nitrate and ammonia. Nanoparticles were synthesized via a surfactant free reaction at room temperature in solvent of water. Products were characterized using X-ray diffraction, scanning electron microscopy, photoluminescence (PL) spectroscopy, and energy dispersive X-ray analysis. The effect of different parameters such as precursor, power of pulsation, surfactant and reaction time on the morphology of the products was investigated. It was found that the as-obtained CeO2 nanoparticles exhibit a strong PL peak at 381 nm at room temperature that can be ascribed to the high level transition in the CeO2 semiconductor. The photocatalytic behavior of CeO2 nanoparticles was evaluated using the degradation of a methyl orange aqueous solution under ultraviolet light irradiation. The results show that CeO2 nanoparticles are promising materials with excellent performance in photocatalytic applications. 相似文献
10.
The present study reports the procedure conducted in SBA-15/CCPy/CuI preparation as a new Mesoporous nanocatalyst, whereas melamine bearing pyridine groups on SBA-15 are used to secure CuI catalyst as capping agent. The resultant catalyst was specified by conducting TEM, FESEM, WDX, ICP, and EDS. The SBA-15/CCPy/CuI catalytic behavior was studied to N-arylation of indole, imidazole, pyrazole, benzyl amine, and aniline by coupling reactions of Ullmann-type CN. Also, the heterogeneous catalyst may simply be recovered via filtration and used again for seven cycles with no considerable loss in activity. The findings revealed the privileges of the present method, including the high product yield, experimental simplicity, low catalyst loading, broad substrate scope, and short reaction times. 相似文献