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1.
Synthesis and characterization of novel flower-like CeF3 nanostructures via a rapid microwave method
Novel flower-like CeF3 nanostructures with a mean diameter of 190 nm were successfully synthesized via a rapid and facile microwave irradiation route using ethylenediaminetetraacetic acid disodium as the complexing reagent. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and photoluminescence (PL). XRD patterns showed that the CeF3 nanoflowers were hexagonal phase and had good crystallinity and purity. TEM and SEM images showed that the as-prepared CeF3 samples displayed 3D flower-like nanostructures and had uniform sizes and morphologies. The experimental results revealed that the as-prepared CeF3 nanoflowers might be assembled by nanodisks. The formation process of the CeF3 nanoflowers was preliminarily investigated. 相似文献
2.
The fine powders of Bi3.25La0.75Ti3O12 (BLT) were prepared by coprecipitaton method in aqueous medium at low temperature. The differential thermal analysis (DTA), thermo-gravimetric analysis (TG) and X-ray diffraction (XRD) were employed to evaluate the phase formation of BLT and TEM was used to characterize and observe the particle size and morphology of BLT powder obtained. The results show that the bismuth layer perovskite phase of BLT can begin to form at as low as 500 °C by the coprecipitation method. When the precipitates obtained were calcined at 600 °C for 2 h, the mono-phase and perfect BLT powder was synthesized. The BLT powder obtained consists of irregular or plate-like particles which are less than about 100 nm and is nearly aggregate free. 相似文献
3.
Co2P nanocrystals were successfully synthesized by a polymer-assisted hydrothermal method. The reaction was carried out at 190 °C-220 °C using cobalt chloride hexahydrate (CoCl2·6H2O) as Co-source and yellow phosphorous as P-source. Polyacrylamide (PAM) was used as surfactant. By controlling the experiment parameters such as the reaction temperature and the amount of polyacrylamide (PAM), Co2P nanocrystals with the rod-like or flower-like morphology could be prepared successfully. The phase and the morphology of the samples were characterized by X-ray diffraction (XRD), transmission electron microscopes (TEM), electron diffraction pattern (ED) and high resolution transmission electron microscope (HRTEM). Furthermore, based on the results of the TEM observation, the possible formation processes of the Co2P nanorods or nanoflowers were also discussed. 相似文献
4.
Flower-like MoS2 microspheres with high purity were successfully synthesized via a facile hydrothermal route by adding sodium silicate as an additive. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). XRD patterns showed that the MoS2 microspheres had good crystallinity with well-stacked layered structure. TEM and SEM images showed that the MoS2 microspheres had uniform sizes with mean diameter about 480 nm and were constructed with MoS2 sheets with thickness of several nanometers. It was found that the possible precursor H4SiMo12O40 obtained by sodium silicate reacting with sodium molybdate played a crucial role in the formation of the flower-like MoS2 microspheres in our experiment. A possible formation mechanism of MoS2 microspheres was preliminarily presented. 相似文献
5.
Fresh niobium hydroxide was first precipitated from NbF5 solution using an aqueous ammonium hydroxide under basic conditions. Then a simple procedure of mixing lithium and niobium hydroxides together and heating at a low temperature (400 °C) produced pure ultrafine single phase LiNbO3 (LN). In the literature, this is the lowest temperature so far reported on the formation of LN. The phase content and lattice parameters are determined by X-ray diffraction (XRD). The average particle size and morphology were studied by transmission electron microscopy (TEM). 相似文献
6.
Manayil Valappil Swapna 《Journal of Experimental Nanoscience》2016,11(7):540-549
Mesoporous anatase TiO2 nanopowder was synthesised by the sol–gel method using ultrasonic irradiation. This method is simple and faster for the synthesis of phase pure mesoporous anatase TiO2 nanopowder. The product is characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron spectroscopy (TEM), thermo gravimetric analysis, Brunauer–Emmett–Teller (BET) surface area, UV–visible diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy. Analysis of XRD patterns, SEM and TEM image shows that the average particles size is of 19.9 nm and has an anatase structure. The mesoporous nature was determined by the BET method using the Barrett–Joyner–Halenda (BJH) model. 相似文献
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8.
In this paper, the cuniform-like MnO2 particles were first successfully synthesized with dodecylbenzenesulfonic acid (DBSA) as surfactant in aqueous solution. The samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and infrared spectroscopy (IR). The possible mechanisms of the shape evolution for the formation of MnO2 samples were discussed. 相似文献
9.
A novel soft chemistry route (rheological phase reaction method) was developed to synthesize nanocrystalline NiFe2O4. The as-prepared samples were characterized by powder X-ray diffractometer (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The effects of the calcination temperature on the particle sizes and magnetic properties of the samples were investigated. The results indicated that the samples obtained by this method had the single-phase spinel. Particle sizes estimated from Scherrer's formula increased with the calcination temperature, which were consistent with the results of TEM. The magnetic properties of the samples were strongly affected by the calcination temperature. The coercivity initially increased and then decreased with increasing calcination temperature whereas the saturation magnetization continuously increased. 相似文献
10.
Cobalt oxide (Co3O4) nanoparticles were successfully synthesized by the cetyltrimethylammonium bromide (CTAB)-assisted method at normal pressure for the first time. The structure and morphology of the as-prepared Co3O4 nanoparticles were characterized by powder X-ray diffracton (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2-sorption analysis. XRD studies indicated that the as-prepared product was well-crystallized cubic phase of Co3O4 with a cell constant of α = 8.0722 Å. The EM images showed that the obtained Co3O4 sample consisted of dispersive quasi-spherical particles with the size ranged from 15 to 25 nm. 相似文献
11.
Intermetallic iron aluminide alloy nanoparticles were synthesized by non-transferred DC plasma spray torch at atmospheric pressure. These powder particles were characterized by vibrating sample magnetometer (VSM), X-ray diffraction (XRD), environmental scanning electron microscopy (ESEM), laser scattering particle size distribution analyzer, energy dispersive X-ray spectra (EDX) and thermo gravimetric-differential thermal analysis (TG/DTA) studies and the results are discussed. Commercially available iron and aluminium powders in the size range between 40 and 100 μm were ball milled with suitable ratio (Fe-85% and Al-15%) by weight to form a iron-aluminium blende; this was used as feed stock to synthesize iron aluminide nanoparticles. These nanoparticles particles were spherical in shape and black in colour, with the size range between 30 and 70 nm observed by ESEM. It is seen that the powders processed at higher power levels (15.3 kW) have more number of single spherical nanoparticles than powders processed at lower power levels (9.8 kW). The formation of iron aluminide nanoparticles is confirmed by XRD analysis and an exothermic reaction by DTA studies. 相似文献
12.
Complexing reagent-assisted microwave synthesis of uniform and monodisperse disk-like CeF3 particles
Highly uniform and monodisperse disk-like CeF3 particles with diameter about 230 nm and thickness about 76 nm were successfully synthesized via a mild and facile microwave irradiation assisted by a complexing reagent, ethylenediamine tetraacetic acid disodium salt (Na2H2EDTA). The morphologies and crystal structure of the products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and scanning electron microscopy (SEM). XRD patterns showed that the as-prepared CeF3 products have hexagonal structure and high crystallinity. SEM images showed that these disk-like CeF3 nanocrystals had rough surfaces which were covered with many sheet-like structures. It was found that the reaction time and the complexing reagent played crucial roles on formation of uniform disk-like CeF3 particles. A possible formation mechanism of the disk-like CeF3 particles was preliminarily presented. 相似文献
13.
Mesoporous PrOy-ZrO2 materials were obtained by coprecipitation process. XRD patterns and TEM images reveal pore size growth with increase in the calcining temperature. N2 adsorption-desorption isotherms of the PrOy-ZrO2 samples are indicative of type IV behavior characteristic of mesoporous materials (as evidenced by low-angle XRD patterns). PrOy-ZrO2 calcined at 500 and 650 °C show well-developed H2 type hysteresis loops, indicating the existence of ink-bottle-like pores with a narrow entrance and a large cavity. PrOy-ZrO2 calcined at 800 and 950 °C show H1 type hysteresis loops, which is often associated with porous materials known to consist of agglomerates of approximately uniform spheres, and hence to have narrow distributions of pore size. The phase analysis by Rietveld refinement method clearly shows the formation of cubic PrOy-ZrO2 solid solution from 500 to 950 °C. 相似文献
14.
The multi-staged formation process of titanium oxide nanotubes was investigated in detail under a hydrothermal treatment. During the synthesis procedure, an intermediate stage (tree-like structures) was observed before the formation of the titanium oxide layered structures. The layered structure of titanium oxide generally was considered to exfoliate directly from raw TiO2 materials through the alkaline hydrothermal treatment. The rolling process of the layered structures of titanium oxide was confirmed by TEM observation after the alkaline hydrothermal treatment for the raw TiO2 materials, followed by washing with 4 M HNO3 aqueous solution. The thermal stability of the tube products was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result showed that both the morphology and crystal phase of titanium oxide nanotubes could be retained even after calcination at 650 °C. 相似文献
15.
Novel Bi2Te3 nanoplates with about 0.2-1 μm in diagonal and 100 nm in thickness have been facilely synthesized via hydrothermal routes in the presence of polyvinylpyrrolidone (PVP). Various techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectrometry (FT-IR) have been used to characterize the obtained products. The results show that the existence of PVP is vital to the formation of the plate-like morphology. Other factors, such as the reaction temperature and the different surfactants also have influence on the morphology of the final products to some extent. 相似文献
16.
The microstructure of a-plane ZnO grown on LaAlO3 (LAO) (001) has been systematically investigated by employing X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Based on the results of XRD and TEM, only a-plane ZnO has been found to grow on LAO (001), and it consists of two types of domains perpendicular to each other. The crystal orientation relationships of a-plane ZnO domains with LAO have been verified to be [0001]ZnO//[110]LAO and [11?00]ZnO//[11?0]LAO. The domain boundaries in the a-plane ZnO are along the direction in a rotation angle of about 45° from the c-axes of ZnO. The surface morphology of ZnO films in SEM exhibits domain structure in stripe-like shape. The formation of two domains can be attributed to the cubic symmetry of the surface configuration of LAO (001). 相似文献
17.
Microwave-assisted green synthesis of MnO2 nanoplates with environmental catalytic activity 总被引:1,自引:0,他引:1
Zhihui Ai Lizhi Zhang Fanhai Kong Hao Liu Wenting Xing Jianrong Qiu 《Materials Chemistry and Physics》2008,111(1):162-167
In this paper, MnO2 nanoplates were synthesized in aqueous solution under the microwave irradiation, without using any templates, catalysts, and organic reagents. The as-prepared MnO2 nanoplates were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and thermo-gravimetric (TG) analysis, and nitrogen sorption measurements. Microwave irradiation could produce MnO2 with uniform size and well-defined shape as well as high crystallinity. On the basis of experimental results, a possible formation mechanism of MnO2 nanoplates was proposed. Furthermore, the resulting MnO2 nanoplates were found to exhibit remarkable environmental catalytic performance in degradation of Rhodamine B (RhB) in aqueous solution, indicating these MnO2 nanoplates is very promising for wastewater treatment. 相似文献
18.
Yongai Zhai 《Materials Letters》2008,62(30):4563-4565
Nanostructure rutile TiO2 was prepared in a carboxyl-containing ionic liquid, 1-methylimidazolium-3-acetate chlorine ([AcMIm]Cl), by using TiOCl2 solution as a precursor at low temperature. The obtained nanostructure TiO2 was analyzed with fourier transform infrared (FTIR), X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The as-prepared TiO2 present only rutile crystal phase and a novel flower-like morphology. The as-prepared rutile TiO2 shows better photocatalytic performance in the degradation of methyl orange. The template-directing performance of ionic liquid is due to the bidentate chelating complexation between the carboxylic functional group of ionic liquid and titania. 相似文献
19.
A. R. Toibah M. Sato M. Yamada M. Fukumoto 《Materials and Manufacturing Processes》2016,31(11):1527-1534
In this work, synthesis of agglomerated TiO2, which is ready to be used after synthesis via a simple hydrolysis process, is described. The as-synthesized TiO2 powders were characterized by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Field Emission Scanning Electron Microscope (FE-SEM), Transmission Electron Microscope (TEM) and DTA. DTA curve indicated that addition of (NH4)2SO4 into the starting precursor has accelerated the hydrolysis of titanyl sulfate. The XRD patterns showed that single-phase anatase TiO2 was produced using low-temperature hydrolysis at 80°C. SEM confirmed that the as-synthesized powders were in agglomerated form and in micro size. Addition of a structure-directing agent (SDA), (NH4)2SO4, promotes agglomeration, with a denser closed packing of particle arrangement, which reduces the number of existing porosities in the synthesized powder. The TEM image showed that the primary particles were nanoparticles. The preliminary study of coating formation depicted that the powder obtained could be used as the feedstock powder for the cold spray (CS) process to make the coating as it can be deposited onto the ceramic tile substrate. 相似文献
20.
T. Sarakonsri T. Apirattanawan S. Tungprasurt T. Tunkasiri 《Journal of Materials Science》2006,41(15):4749-4754
Intermetallic dendrite particles, such as Cu6Sn5 compound, possible anode materials for high power lithium-ion batteries, can be synthesized by using solution technique. Solution route method can induce the formation of the compound by performing a redox reaction between metal chloride salts and metallic reducing powder in a suitable solvent. The morphological features and single-phase formation corresponding to different processing conditions including solvent type, reducing agent particle size, and reaction temperature, were determined. The X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) results illustrate the dendritic morphology of Cu6Sn5 particles with small amount of impurities, which can be synthesized by using ethylene glycol as solvent and zinc powder as reducing agent. Reducing agent particle size and reaction temperature have a very small effect on the formation of the Cu6Sn5 dendrite powder. 相似文献