Dissolution Characteristics and Morphology of Large-sized Scorodite Particles Synthesized from Fe(II) and As(V) in Aqueous Solution

2012 ◽  
Vol 31 (4-5) ◽  
pp. 451-458 ◽  
Author(s):  
S. Fujieda ◽  
K. Shinoda ◽  
T. Inanaga ◽  
M. Abumiya ◽  
S. Suzuki

AbstractA novel process for preparing scorodite particles with a diameter of approximately 20 µm from Fe(II) and As(V) in aqueous solution has been developed by DOWA Metals and Mining. In the present study, the dissolution characteristics of iron and arsenic from the scorodite particles synthesized by this process have been investigated under different conditions. The results show that the concentration of arsenic dissolved from the particles in aqueous solution is very low, but it has a complicated dependence on the temperature and pH of the solution. Transmission electron microscopy (TEM) with an energy dispersive X-ray spectrometer (EDS) was used to analyze the morphology, structure, and composition of the scorodite particles. The results indicate that the scorodite particles exhibit a nearly octahedral shape with planes composed of almost (111) planes in the orthorhombic structure. The concentration of iron at the surface of the particles is higher than that of iron inside of the particles. This characteristic morphology, along with the minimal surface defects of the scorodite particles, is considered to be responsible for the low dissolution of arsenic from the particles in aqueous solution. Atmospheric temperature and solution conditions were also found to be important for the safe, long-term storage of arsenic using scorodite particles.

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1238
Author(s):  
Murendeni P. Ravele ◽  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Damian C. Onwudiwe

In this paper, spherical-shaped pure phase djurleite (Cu31S16) and roxbyite (Cu7S4) nanoparticles were prepared by a solvothermal decomposition of copper(II) dithiocarbamate complex in dodecanthiol (DDT). The reaction temperature was used to control the phases of the samples, which were represented as Cu31S16 (120 °C), Cu31S16 (150 °C), Cu7S4 (220 °C), and Cu7S4 (250 °C) and were characterized by using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and absorption spectroscopy. The samples were used as photocatalysts for the degradation of tetracycline (TC) under visible light irradiation. The results of the study showed that Cu7S4 (250 °C) exhibited the best activity in the reaction system with the TC degradation rate of up to 99% within 120 min of light exposure, while the Cu31S16 (120 °C) system was only 46.5% at the same reaction condition. In general, roxbyite Cu7S4 (250 °C) could be considered as a potential catalyst for the degradation of TC in solution.


NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950138 ◽  
Author(s):  
Sai Zhang ◽  
Shijun Yue ◽  
Jiajia Li ◽  
Jianbin Zheng ◽  
Guojie Gao

Au nanoparticles anchored on core–shell [Formula: see text]-Fe2O3@SnO2 nanospindles were successfully constructed through hydrothermal synthesis process and used for fabricating a novel nonenzymatic dopamine (DA) sensor. The structure and morphology of the Au/[Formula: see text]-Fe2O3@SnO2 trilaminar nanohybrid film were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical properties of the sensor were investigated by cyclic voltammetry and amperometry. The experimental results suggest that the composites have excellent catalytic property toward DA with a wide linear range from 0.5[Formula: see text][Formula: see text]M to 0.47[Formula: see text]mM, a low detection limit of 0.17[Formula: see text][Formula: see text]M (S/[Formula: see text]) and high sensitivity of 397.1[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text]. In addition, the sensor exhibits long-term stability, good reproducibility and anti-interference.


2010 ◽  
Vol 663-665 ◽  
pp. 100-103
Author(s):  
Zhen Ni Du ◽  
Yong Cai Zhang ◽  
Zhi You Xu ◽  
Ming Zhang

The synthesis of hexagonal phase Zn1-xMnxS (x = 0–0.05) nanorods was achieved by hydrothermal treatment of zinc manganese diethyldithiocarbamates (Zn1-xMnx-(DDTC)2, x=0–0.05) in 40 mass % hydrate hydrazine aqueous solution at 180 °C for 12 h. The structure, composition and optical property of the obtained products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra.


2019 ◽  
Vol 27 (4) ◽  
pp. 61-64
Author(s):  
V. N. Nikolenko ◽  
A. L. Urakov ◽  
L. I. Rastegaeva ◽  
E. A. Kozyreva ◽  
L. A. Gridin ◽  
...  

For storage and open demonstration of moist anatomical educational preparations and museum exhibits proposed to use a new preservative, which is an aqueous solution of 0.014-0.019% 3-iodine-2-propinilbutilcarbonate. The solution has high antiseptic activity and does not have a local irritant effect on the skin, mucous membranes of the upper respiratory tract and oral cavity, as well as on the conjunctiva of the eyes. The proposed preservative is non-toxic and environmentally safety. Long-term storage and use of anatomical preparations in the proposed preservative does not cause any damaging changes, violations of their shape, structure and color. The method is patented by the Russian Patent Agency.


2004 ◽  
Vol 19 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Yury Teterin ◽  
Serguei Stefanovskij ◽  
Serguei Yudintsev ◽  
George Bek-Uzarov ◽  
Anton Teterin ◽  
...  

The synthesis of ceramic matrixes for the long-term storage of highly active radionuclide wastes and determination of physical and chemical forms of radionuclides in them is one of the important problems in radioecology. It enables to create purpose fully materials for the long-term storage of radionuclides. In the present work the samples of ceramics [CaCe0.9Ti2O6.8(I) and CaCeTi2O7(II}] formed under various conditions were investigated with the X-ray photo electron spectroscopy. It is necessary for synthesis of ceramic matrixes, for the disposal of the plutonium and others tetravalent actinides. A technique was developed for the determination of cerium oxidation state (Ce3+ and Ce4+) on the basis of the X-ray photo electron spectroscopy spectral structure characteristics. It was established that the sample (I) formed at 300 MPa and T = 1400 ?C in the air atmosphere contained on the surface two types of cerium ions in the ratio ? 63 atomic % of Ce3+ and 37 atomic % of Ce4+, and the sample (II) formed at 300 MPa and T= 1300 ?C in the oxygen atmosphere contained on its surface two types of cerium ions also, but in the ratio ? 36 atomic % of Ce3+ and 64 atomic % of Ce4+. It was established that on the surface of the studied ceramics carbonates of calcium and/or cerium could be formed under influence of the environment that leads to the destruction of ceramics.


e-Polymers ◽  
2016 ◽  
Vol 16 (3) ◽  
pp. 177-180 ◽  
Author(s):  
Zheng Peng ◽  
Hong Li ◽  
Xinwu Ba ◽  
Junchai Zhao ◽  
Xiuguo Sun ◽  
...  

AbstractIntramolecular nanocavities in polyamidoamine (PAMAM) are usually used as a good template to synthesize nanoparticles. In this paper, TiO2 nanoparticles were prepared successfully by the interspaces of the hydrogen network between PAMAM. The possible mechanism was that PAMAM could form the steady microspheres with many interspaces in ammonia aqueous solution at pH=10. The interspaces of the hydrogen network could act as the template for preparing TiO2 nanoparticles. The results were proved by transmission electron microscopy (TEM) and X-ray diffraction (XRD).


2014 ◽  
Vol 887-888 ◽  
pp. 108-111
Author(s):  
Zao Yi ◽  
Jiang Shan Luo ◽  
Xi Bo Li ◽  
Yong Yi ◽  
Xi Bin Xu ◽  
...  

In this paper a simple eco-friendly wet-chemical way was mentioned to synthesize gold nanoplates. The prepared of the gold nanoplates was a seedless process that carried out by mixing HAuCl4 aqueous solution and Tannic acid (TA) solution at room temperature without the other surfactant and capping agents. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) have been used to characterize the shape and composition the prepared gold nanoplates. The molar ratio of HAuCl4 and TA can control the shape and the size of gold nanoplates effectively. This research can provide a simple and eco-friendly way for the prepared gold nanoplates in aqueous solution.


2007 ◽  
Vol 40 (4) ◽  
pp. 796-798 ◽  
Author(s):  
Bingyun Ao ◽  
Xiaolin Wang ◽  
Yongjun Wei ◽  
Yanzhi Zhang

In order to help resolve unknowns regarding aging effects of uranium during long-term storage of tritium, a number of experiments have been carried out by several researchers. However, almost no literature is available on the structural change of uranium tritide, mainly because its high toxicity and air-sensitivity render appropriate experiments very difficult. In this paper, a simple hermetic sample holder that fits the Philips X'Pert Pro X-ray diffractometer is described. It may be used to study the aging effects of uranium tritide during storage. The sample holder mainly consists of an aluminium container for sample storage and a Mylar window for X-ray measurements. This sample holder can also be used with other air-sensitive, radioactive and toxic materials. In this paper, the first results obtained from X-ray diffraction analysis of uranium hydride are presented.


1989 ◽  
Vol 164 ◽  
Author(s):  
Toby J. Cumberbatch ◽  
Andrew Putnis

AbstractIndium arsenide colloids have been prepared by passing arsine through an aqueous solution of the metal nitrate. Similar experiments with gallium solutions produced an extremely fine precipitate which has been tentatively identified as amorphous gallium arsenide. Attempts to precipitate aluminium arsenide from aqueous solutions or mixed organic solvent systems were unsuccessful. The materials were characterised by transmission electron microscopy, X-ray powder diffraction and and optical absorption spectroscopy.


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