Low-Cost Synthesis and Morphology Control of Magnesium Oxysulfate Hydrate Whiskers

2014 ◽  
Vol 936 ◽  
pp. 986-991
Author(s):  
Chuan Hui Gao ◽  
Li Ding ◽  
Yu Min Wu ◽  
Chuan Xing Wang ◽  
Jun Xu

A low-cost raw material, bittern obtained from the production process of sea salt, was used to prepare magnesium oxysulfate hydrate (MgSO4·5Mg (OH)2·2H2O, abbreviated as 152MOS) whiskers via hydrothermal synthesis with ammonia and magnesium sulfate as the other starting raw materials. The bittern was firstly filtered and then used directly without de-coloring. X-ray powder diffraction (XRD), transmission electron microscope (TEM), selected area electron diffraction (SAED), energy dispersive X-ray spectroscopy (EDX) and scanning electron microscope (SEM) were employed to investigate the composition and morphology of the products. It was found that the 152MOS whiskers synthesized from bittern at 190°C for 3 hours exhibited fanlike morphology. The formation of the fanlike whiskers was inhibited and most of the whiskers presented as single fibers when ethanol was used as crystal control agent in the hydrothermal process. From the two-dimensional steps observed at tips of the whiskers, a possible growth mechanism was speculated that it was the extension of dislocations that made the growth of the whiskers.

2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.


2014 ◽  
Vol 809-810 ◽  
pp. 122-127 ◽  
Author(s):  
Li Xiong Yin ◽  
Fei Fei Wang ◽  
Jian Feng Huang ◽  
Dan Wang ◽  
Jia Yin Li

SnO2nanocrystals were synthesized using SnCl4•5H2O and NH3•H2O as the main raw materials and distilled water as the solvent by microwave hydrothermal. Reaction temperature on the structure and photocatalytic activities of the SnO2nanocrystals by microwave hydrothermal process was studied. The phase composition, morphologies and photocatalytic activities of the product were characterized by XRD (X-ray diffraction), SEM (scanning electron microscope), TEM (transmission electron microscope) and photochemical reaction instrument. Results show the crystalline and conglobation of the product have significant effect on its photocatalytic properties. The homogeneous low-agglomerated and well crystallined SnO2nanocrystals prepared at 180 °C has good photocatalytic activities during photocatalytic degradation of RhB process.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Beomjin Kim ◽  
Woo Chang Song ◽  
Sun Young Park ◽  
Geuntae Park

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics.


2007 ◽  
Vol 7 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Bo Zhou ◽  
Jun-Jie Zhu

A chemical co-reduction route in aqueous solution was developed to synthesize Bi100−xSbx alloys at room temperature. The hydrolyses of Bi(III) and Sb(III) were effectively avoided by selecting proper raw materials and coordinator. X-ray diffraction analysis indicated that the as-prepared Bi100−xSbx alloys were homogeneous and phase-pure, and the Bi/Sb ratios in the alloys were very close to those in the aqueous solutions. The transmission electron microscope observation showed that the as-prepared Bi100−xSbx (x = 0∼100) alloys were particles with a size of tens of nanometers. The selected area electron diffraction patterns confirmed the high crystallinity, the homogeneousness, and the composition controllability of as-prepared alloys. All these characters and the nanometer-scaled size of the alloys are believed to be beneficial to the thermoelectric property of the Bi100−xSbx alloys.


2008 ◽  
Vol 8 (1) ◽  
pp. 335-339 ◽  
Author(s):  
Satyendra Singh ◽  
S. B. Krupanidhi

Multiferroic BiFeO3 (BFO) nanotubes have been successfully fabricated by the modified sol–gel method within the nanochannels of porous anodic aluminum oxide (AAO) templates. The morphology, structure and composition of the nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), selected-area electron diffraction (SAED), high resolution TEM, (HRTEM) and energy-dispersive X-ray spectroscopy (EDX). Postannealed (650 °C for 1 h), BFO nanotubes were polycrystalline and X-ray diffraction study revealed that they are of the rhomohedrally distorted perovskite crystal structure. The results of SEM and TEM revealed that BFO nanotubes possessed a uniform length (up to 60 μm) and diameter (about 200 nm), which were controlled by the thickness and the pore diameter of the applied AAO template, respectively and the thickness of the wall of the BFO nanotube was about 15 nm. Y-junctions in the BFO nanotubes were observed. EDX analysis demonstrated that stoichiometric BiFeO3 was formed. HRTEM analysis confirmed that the obtained BFO nanotubes made up of nanoparticles (3–6 nm). The possible formation mechanism of BFO nanotubes was discussed.


Author(s):  
Chuan Bao Cao ◽  
Ruitao Lv ◽  
He Sun Zhu

Nanorods of a compound semiconductor, BiOCl, have been prepared from BiCl3 solutions containing a nonionic surfactant, t-octyl-(OCH2CH2)xOH, x=9, 10 (Triton X-100). Powder X-ray diffraction (XRD) pattern indicated that the product was pure tetragonal phase bismoclite (BiOCl). The product was also characterized by the techniques of scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscope (TEM). The as-obtained BiOCl nanorods possess mean diameters less than 40nm and lengths ranging in 160-400nm. Selected area electron diffraction (SAED) pattern showed the single-crystal nature of as-prepared BiOCl nanorods. The growth mechanism of BiOCl nanorods has also been proposed.


2017 ◽  
Vol 268 ◽  
pp. 172-176 ◽  
Author(s):  
Nurul Norfarina Hasbullah ◽  
Oon Jew Lee ◽  
Josephine Liew Ying Chyi ◽  
Soo Kien Chen ◽  
Zainal Abidin Talib

In this work, BaTiO3 nanoparticles were synthesized through hydrothermal method. The powder obtained from the hydrothermal process (as-synthesized powder) was calcined at 1000 °C. The phase formation and morphology of the as-synthesized and calcined powders were studied using X-ray diffraction (XRD), thermogravimetric (TGA) and differential scanning calorimetry (DSC) analyzer, and transmission electron microscope (TEM). The XRD data showed that the as-synthesized powder is partially amorphous. Upon calcining the powder at 1000 °C, highly crystalline BaTiO3 with tetragonal structure was obtained. As shown by TGA and DSC analysis, the precursor powder was completely transformed into BaTiO3 at 1000 °C. The presence of BaCO3 as an impurity phase in the powder is due to the lack of Ba2+ / Ti3+/4+. Transmission electron microscope images showed that the particle size of the as-synthesized powder increased after calcination due to crystal growth. In addition, nanocubes with the average size of around 11.66 nm were obtained as a result of the calcination compared to the ellipsoid like particles of the as-synthesized powder.


2020 ◽  
Vol 27 (11) ◽  
pp. 2050003
Author(s):  
HONGXIA LI ◽  
CHAO YANG ◽  
JIAN ZHANG ◽  
XIANGUO LIU ◽  
XUEFENG ZHANG

Recently, Co(OH)2 has gained much attention as a promising electrocatalyst. Herein, we synthesized Co(OH)2-decorated TiO2 film for electrocatalytic water splitting by a facile and low-cost electrochemistry method, which possessed enhanced performance for oxygen evolution reaction. The results of X-ray diffractometry, transmission electron microscope, scanning electron microscope and X-ray photoelectron spectroscopy verify the successful decoration of Co(OH)2 electrocatalysts onto the surface of TiO2. Moreover, photoelectrocatalytic measurements illustrate that the Co(OH)2-decorated TiO2 shows higher current density than pure TiO2 sample. The results obtained in this work give deep insights into the development of photoelectrochemical water splitting.


2007 ◽  
Vol 561-565 ◽  
pp. 243-246 ◽  
Author(s):  
Junya Nakamura ◽  
Kenji Matsuda ◽  
Yoshio Nakamura ◽  
Tatsuo Sato ◽  
Susumu Ikeno

The purpose of this study is to identify the crystal structure of metastable phase in Ag added Al-Mg-Si alloy to compare the formation of β’-phases in Al-Mg-Si alloys without Ag, using images of high resolution transmission electron microscope (HRTEM), selected area electron diffraction (SAED) patterns and an energy dispersive X-ray spectroscopy (EDS). The result of SAED patterns and HRTEM images have been simulated and compared with images then SAED patterns obtained from actual precipitates. SAED patterns and HRTEM images obtained from metastable phase in the Ag added Al-Mg-Si alloy showed similar to those of β’-phase in Al-Mg-Si alloy without Ag and the lattice spacings changed because of the effect of Ag.


2014 ◽  
Vol 1033-1034 ◽  
pp. 1040-1043 ◽  
Author(s):  
Bin Deng ◽  
Hai Ying Huang

In this Letter, we reported the facile synthesis of manganese (III) oxide (Mn2O3) nanowires via the facile hydrothermal treatment in the presence of ammonia, which were prepared simply by hydrothermal treatment of commercial bulky Mn2O3crystals at 160oC for 24 h. The obtained Mn2O3products consist a large quantity of nanwires with the diameters of 30-90 nm, and lengths ranging from 1 to 10 μm. Such high quality nanowires with high aspect ratio have a variety of promising applications. The simplicity of hydrothermal process, cheapness, and availability of raw materials, without the need of catalyst or template, are advantages favoring industrial manufacturing in scaled-up process by the novel method. X-ray and transmission electron microscopy, electron diffraction, and scanning electron microscopy have been employed to characterize these materials. In addition, the possible growth mechanism of the Mn2O3nanowires was also proposed. The growth of Mn2O3nanowires occurredviaa dissolution-recrystallization process.


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