Synthesis of La2NiO4+δ Nanofibers by Electrospinning Method and their Application

2018 ◽  
Vol 281 ◽  
pp. 859-864
Author(s):  
Yan Xing ◽  
Meng Fei Zhang ◽  
Tian Jun Li ◽  
Wei Pan

La2NiO4+σ nanofibers exhibiting typical Ruddlesden–Popper structure (K2NiO4) were fabricated by a facile electrospinning method. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to analyze the structure, morphology and crystal process of the La2NiO4+σ nanofibers. For electrical properties measurement, uniaxially aligned nanofibers were directly collected and assembled into electrode. In our research, La2NiO4+σ phase forms above 873K with no impurity phase emerges during the thermal treatments. The nanofibers are smooth and uniform throughout the entire length and the grain is growing as calcination temperature increases. Furthmore, the La2NiO4+σ nanofibers own high mixed conductivity at 773K, laying good foundation for intermediate temperature solid oxide fuel cells application.

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.


2011 ◽  
Vol 356-360 ◽  
pp. 565-568
Author(s):  
Shao Hong Wei ◽  
Mei Hua Zhou ◽  
Wei Ping Du

Pure ZnO and SnO2-ZnO nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and methanol sensing properties of these fibers were investigated. The results indicate that the 20 wt% SnO2-ZnO sensor exhibits considerable sensitivity, rapid response, and good selectivity against methanol at 200 °C due to the special 1D fibers properties and the promoting effect of SnO2/ZnO heterojunction structure. The methanol sensing mechanism of SnO2-ZnO nanofibers were also discussed.


2011 ◽  
Vol 52-54 ◽  
pp. 1884-1889 ◽  
Author(s):  
Dariush Jafar Khadem ◽  
Zahira Yaakob ◽  
Samaneh Shahgaldi ◽  
Wan Ramli Wan Daud ◽  
Edy Herianto Majlan

Metal and Metal oxide nanofibers have different potential to play an essential role in a series of application, among them copper and copper oxide nanostructures is a promising semiconductor material with potential applications in many field. In this paper, electrospinning method via sol-gel was used to fabricate copper and copper oxide nanofibers. Synthesize of copper and copper oxide nanofibers and also effect of calcinations temperature on morphology investigated by thermal gravimetric analysis, scanning electron microscopy (SEM), Transmission electron microscopy, x-ray diffraction(XRD), Fourier transform infrared spectroscopy (FTIR) and Brunauer Emmett and Teller (BET).


2007 ◽  
Vol 336-338 ◽  
pp. 2005-2007
Author(s):  
Xiang Feng Guan ◽  
Zhi Hui Liu ◽  
He Ping Zhou

Nanosized Ce0.8Gd0.05Y0.15O1.9 powders were synthesized using glycine nitrate process for use as the electrolyte of intermediate temperature solid oxide fuel cells. The powders were characterized by simultaneous thermogravimetry analysis (TGA) and differential thermal analysis (DTA), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD pattern indicated that the powders exhibited a single phase with cubic fluorite structure. The TEM studies showed that the calcined powders exhibited an almost spherical morphology and the mean size of the particles was 30nm, which is in agreement with the calculated result of XRD.


2009 ◽  
Vol 79-82 ◽  
pp. 1281-1284 ◽  
Author(s):  
Bo Yang Liu ◽  
De Chang Jia ◽  
Li Hua Dong ◽  
Yan Sheng Yin

Hollow carbon spheres containing Fe3N nanocrystals (Fe3N/HCSs) are synthesized by ferrocene and ammonium chloride in high pressure argon at 500 °C. The structure, morphology and properties of the products are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG) and vibrating sample magnetometry (VSM). The hollow carbon spheres have diameters of 1-10 µm and shell thickness of hundreds of nanometers. The dimensions of the acicular Fe3N nanocrystals have diameters of ca. 100 nm and lengths of 600-800 nm. The weight percent of Fe3N nanocrystals in Fe3N/HCSs is about 37.8%. The saturation magnetization value of the hollow carbon spheres containing Fe3N nanocrystals is 10.61 emu/g.


2020 ◽  
Vol 40 (4) ◽  
pp. 321-332
Author(s):  
Yuan Lin ◽  
Yangchuan Ke ◽  
Chengcheng Yu ◽  
Xu Hu ◽  
Shichao Lu ◽  
...  

AbstractExfoliated organo-montmorillonite (O-Mt) layers were successfully encapsulated in a terpolymer microsphere (PAAA) of acrylamide (AM)/acrylic acid (AA)/2-acrylamido-2-methylpropanesulfonic acid (AMPS) via in situ inverse suspension polymerization, with the aid of the organic modification by cetyltrimethylammonium bromide (CTAB) and sodium lauryl sulfonate (SLS). The chemical structure and properties of the Mt were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), which showed that SLS molecules successfully intercalated Mt interlayers and enhanced the thermostability of Mt. The microsphere morphologies of the polymer and its nanocomposites were detected by scanning electron microscopy (SEM). The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed that the exfoliated O-Mt dispersed in the polymer matrix. The introduction of well-dispersed O-Mt layers significantly enhanced the comprehensive performance of these microspheres, including thermostability and plugging properties. The Tmax of PAAA/1.5 wt.% O-Mt nanocomposite is increased by 46°C compared to the pure terpolymer. The plugging rate of PAAA/2.0 wt.% O-Mt reached up to 85.8%. Therefore, these selected nanocomposite microspheres can provide an effective plugging in the high-permeability layers.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
R. X. Chen ◽  
S. L. Zhu ◽  
J. Mao ◽  
Z. D. Cui ◽  
X. J. Yang ◽  
...  

The highly efficient CuO/Co3O4composite photocatalyst with different morphologies has been synthesized directly on Cu wire mesh by controlling the composition of cobalt-containing solid precursors via a simple hydrothermal method. The structure morphology and composition of the composite photocatalyst have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible diffuse reflectance spectra. The photocatalytic result shows that the CuO/Co3O4coaxial heterostructure is easy to recycle and exhibit enhanced photodegradation activity for methylene blue compared to single CuO nanorod arrays under full spectrum solar light irradiation. The enhanced photocatalytic efficiency of the composite could be ascribed to the synergistic effect of CuO and Co3O4. This study provides a general and effective method in the fabrication of 1D composition NRs with sound heterojunctions that show enhancement of photocatalytic performance and facility of recycling.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bamba Mahman ◽  
Mpho Enoch Sithole

A series of undoped mixed-phase BaAl2O4/CaAl4O7 (hereafter called BC) and doped BC: x% Eu3+ (0 < x ≤ 5.5) nanophosphors were successfully prepared by the citrate sol-gel technique. Their structure, morphology, and optical properties were studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD and SEM showed that all the BC:x% Eu3+ samples consisted of the crystalline structure of the mixed phases of both the BaAl2O4 and CaAl4O7 materials. The structure resembles more that of the BaAl2O4 than the CaAl4O7 phase. The TEM results suggest that the crystallite sizes are in the nanometer scale with rod-like particles. PL results showed multiple emission peaks located at 436, 590, 616, 656, and 703 nm, which were assigned to the intrinsic defects within the BC matrix, 5D0 ⟶ 7F1, 5D0 ⟶ 7F2, 5D0 ⟶ 7F3, and 5D0 ⟶ 7F4 transitions of Eu3+, respectively. The decay curves evidently showed that the nanophosphors have persistent luminescence. The Commission Internationale de l’Eclairage (CIE) analysis revealed that doping has tuned the emission colour from blue to orange-red. The results indicate that the Eu3+-doped samples can potentially be used in the orange/red-emitting phosphors.


2011 ◽  
Vol 239-242 ◽  
pp. 356-359 ◽  
Author(s):  
Hai Yan Xu ◽  
Ling Xu ◽  
Shi Biao Wu ◽  
Xu Dong Wang ◽  
Hao Wang

YVO4 nanoparticles with various morphologies were tuned directly by hydrothermal treatment in different solutions, including pure water, potassium hydroxide solution, hydrazine hydrate, ethanolamine, triethylamine, and pyridine. X-ray diffraction (XRD), Raman, and transmission electron microscopy (TEM) were utilized to characterize the structure, morphology, and size of the products, which indicated that tetragonal phase YVO4 crystallites displaying rod-like, square, and olivary shapes were obtained. It was found that the selected solvents play an important role in modulating the morphology and confining the size of the obtained products.


Author(s):  
R. Gronsky

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.


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