scholarly journals A Salt-Assisted Combustion Method to Prepare Well-Dispersed Octahedral MnCr2O4Spinel Nanocrystals

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Yuping Tong ◽  
Juntao Ma ◽  
Shunbo Zhao ◽  
Hongyuan Huo ◽  
Hailong Zhang

Well-dispersed nanocrystalline MnCr2O4was prepared by a salt-assisted combustion process using low-toxic glycine as fuel and Mn(NO3)2and Cr(NO3)3·9H2O as raw materials. The obtained products were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy, Raman spectroscopy, Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM). The fabrication process was monitored by thermogravimetric and differential thermal analysis (TG-DTA). The phase formation process was detected by XRD, and MnCr2O4single phase with high crystallinity was formed at 700°C. TEM and SEM images revealed that the products were composed of well-dispersed octahedral nanocrystals with an average size of 80 nm. Inert salt-LiCl played an important role in breaking the network structure of agglomerated nanocrystallites.

2012 ◽  
Vol 238 ◽  
pp. 79-82
Author(s):  
Yu Ping Tong ◽  
Xi Chen ◽  
Shun Bo Zhao ◽  
Lu De Lu

Ultrafine square-shaped pyrochlore-type Nd2Sn2O7 nanocrystals were synthesized by a convenient salt-assisted combustion process using glycine as fuel. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results indicate that the products are phase-pure nanocrystals with pyrochlore-type structure. TEM and HRTEM images reveal that the products are composed of well-dispersed square-shaped Nd2Sn2O7 nanocrystals with the average size of 30 nm and the crystallite is structurally uniform and crystalline. The presented method provides a convenient and low-cost route for the synthesis of oxide materials nanostructures.


2011 ◽  
Vol 347-353 ◽  
pp. 3472-3476
Author(s):  
Guang Xiu Cao ◽  
Tian Liu ◽  
Qing Hong Zhang ◽  
Hong Zhi Wang

A simple method for preparing nanoscale copper ferrite particles with narrow distribution and uniform size was developed by auto-combusting the precursor using copper nitrate, iron nitrate, and malic acid as raw materials. The constituents and the thermal decomposition process of the precursor were studied by Fourier transform infrared (FT-IR), thermogravimetry-differental thermal analysis (TG-DTA) and X-ray diffraction (XRD). The results showed that the carboxyl and nitrate ion take part in the reaction during the auto-combustion process. The precursor decomposed completely at about 199 °C, to yield single phase product. Transmission electron microscopy (TEM) indicated that the average size of the as-burnt sample was about 90 nm.


2011 ◽  
Vol 306-307 ◽  
pp. 1257-1261 ◽  
Author(s):  
Yun Shan Bai ◽  
Lu De Lu ◽  
Jian Chun Bao

Nanocrystalline Fe3+-doped La2Zr2O7 series solid solutions were prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results showed the La ion can be partially replaced by Fe ion. The partial substituted products were still single-phase solid solutions and the crystal form remained unchanged. TEM images reveal that the products are composed of well-dispersed square-shaped nanocrystals. The method provides a convenient and low-cost route for the synthesis of nanostructures of oxide materials. The fluorescence of La1.8Fe0.2Zr2O7 nanocrystals was evaluated by the UV-visible absorption spectra and the fluorescence spectra. The results indicate that (LaxFe1-x)2Zr2O7 nanocrystals prepared by this method are a kind of potential fluorescent-emitted material.


2013 ◽  
Vol 678 ◽  
pp. 248-252
Author(s):  
K. Kavi Rasu ◽  
Dhandapani Vishnushankar ◽  
V. Veeravazhuthi

Bismuth sulfide (Bi2S3) and Polyvinyl pyrrolidone (PVP) encapsulated Bi2S3 Nanoparticles are synthesized from aqueous solutions at room temperature. Synthesized samples are subjected to UV-Visible Spectroscopy, X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX), Transmission Electron Microscopy (TEM) and FT-IR studies and their results are compared. X-ray diffraction spectrum reveals the crystalline nature of the synthesized samples. Grain size value of PVP/ Bi2S3 nanoparticles show a decrease when compared to Bi2S3 nanoparticles and this ensures the good encapsulant effect of PVP on Bi2S3 nanoparticles. SEM images show that all the particles in the synthesized sample are nearly equal in size. From the TEM image we conclude that the particle size lies between 30nm to 70nm. Finally the samples are subjected to EDAX studies for determining their composition.


2016 ◽  
Vol 35 (5) ◽  
pp. 493-498
Author(s):  
Masoud Salavati-Niasari ◽  
Mahdiyeh Esmaeili-Zare ◽  
Mina Gholami-Daghian ◽  
Samira Bagheri

AbstractManganese oxyhydroxide (MnOOH) nanoparticles were synthesized by the reaction of [Mn(Hsal)2] complex and NaOH in the presence of ultrasound irradiation. In this study, the effect of different reaction parameters such as type of solvent, sonication time and type of surfactant on the morphology and the particle size of product were studied. The as-synthesized nanoparticles, with an average size of 10–15 nm, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and energy dispersive spectrometry (EDS). To the best of author’s knowledge, it is the first time that [Mn(Hsal)2] complex is used as manganese source for the synthesis of MnOOH nanoparticles.


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.


2010 ◽  
Vol 123-125 ◽  
pp. 1291-1294 ◽  
Author(s):  
Bin Lü ◽  
Jian Zhong Ma ◽  
Dang Ge Gao ◽  
Lei Hong

Modified rapeseed oil(MRO) was prepared by using rapeseed oil, ethylene diamine and acrylic acid as the raw materials. Modified rapeseed oil/montmorillonite(MRO/MMT) nanocomposite was prepared by using modified rapeseed oil and montmorillonite. The emulsifying properties of MRO and MRO/MMT were determined respectively. Fourier transforms infrared spectrometry (FT-IR) and Transmission Electron microscope (TEM) results showed that MRO/MMT was prepared successfully. X-ray diffraction (XRD) results showed that modified rapeseed oil could smoothly enter the interlayer of montmorillonite, and modified the montmorillonite; with an increase in the amount of montmorillonite, the layer spacing of montmorillonite in the MRO/MMT lower after the first increase. The results of emulsifying properties indicated that emulsifying properties of MRO/MMT was better than MRO.


2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.


2013 ◽  
Vol 655-657 ◽  
pp. 1927-1930 ◽  
Author(s):  
Guang Na Zhang ◽  
Zhi Yue Xia ◽  
Jian Ming Ouyang ◽  
Li Kuan

The presence of crystallites in urine is closely related to stones formation. In this article, the components, morphology of nano- and micro-crystallites in urines of 20 uric acid (UA) stone formers as well as their relationship with the formation of UAstones were comparatively studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The main constituent of urinary crystallites was uric acid. Their particle size distribution was highly uneven, ranging from several nanometers to several tens of micrometers, and obvious aggregation was observed. These results showed that there was close relationship among stone components, urinary crystallites composition and urine pH.


2011 ◽  
Vol 412 ◽  
pp. 5-8 ◽  
Author(s):  
Ying Zhang ◽  
Ai Chen ◽  
Hai Rong Wang ◽  
Ze Song Li ◽  
Ying Ping Shen

The present article reports the results of studies related to the synthesis of nanocrystalline ceria powder by combustion process using salt combustion aid. Cerium nitrate as oxidant and urea as fuel were used as reagents, Sodium Chloride was compared as combustion aid. The phase analysis and particle size were compared. The product was characterized by X-ray diffraction, Scanning electron microscopy and Transmission electron microscopy. The results showed that employment of starting fuel with combustion aid resulted in synthesizing nanocrystalline ceria powder with fine agglomerates. By using combustion aid, the energetics of the combustion reaction and particle characteristics have been changed.


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