Determination of Iron, Chromium, and Nickel by Fluorescent X-Ray Analysis. Aqueous Solution Method

1959 ◽  
Vol 31 (6) ◽  
pp. 1069-1072 ◽  
Author(s):  
W. W. Houk ◽  
Louis. Silverman
2013 ◽  
Vol 06 (06) ◽  
pp. 1350058 ◽  
Author(s):  
YUAN MING HUANG ◽  
QING-LAN MA ◽  
BAO-GAI ZHAI

A facile and green method was utilized to synthesize core-shelled Zn / ZnO microspheres by boiling Zn microparticles in water for improving the photocatalytic activity of ZnO . The synthesized Zn / ZnO core-shells were investigated by means of scanning electron microscope, X-ray diffractometer and photoluminescence spectrometer, respectively. The morphology analysis showed that the metallic Zn core was about 6 μm in diameter while the ZnO shell was about 600 nm in thickness. Compared to ZnO nanoparticles, the core-shelled Zn / ZnO microspheres exhibited improved photocatalytic activity in degrading methyl orange in water. Our results suggest that the metal–semiconductor junction formed at the Zn / ZnO interface is responsible for the enhanced photocatalytic activity of ZnO .


2013 ◽  
Vol 770 ◽  
pp. 120-123
Author(s):  
P. Limnonthakul ◽  
C. Chananonnawathorn ◽  
K. Aiempanakit ◽  
J. Kaewkhao ◽  
P. Eiamchai ◽  
...  

The ZnO nanorods were fabricated on top of the seeded gold layer by the aqueous solution method with the solution of zinc nitrate and hexamethylenetetramine (HTMA) at 90°C for 24 hours. The variety of the ZnO nanorods were prepared and investigated based on the precursor concentrations, in a range of 1 to 40 mM. The physical morphologies and crystal structures were characterized by field-emission scanning electron microscopy (FE-SEM) and X-ray diffractometry (XRD), respectively. The results showed that, with the small precursor concentrations, the lateral growth of the nanorods was highly significant when compared to their axial growth. The precursor concentration of 20 mM was best optimized for the preparation of the ZnO nanorod arrays with the hexagonal structures at the highest rod diameter and length. At the higher concentrations, although the nanorod size remained nearly constant, the length was however rapidly decreased. Further analyses also proved that, with the increased precursor concentrations, the number density of the ZnO nanorods was progressively increased along with the more complete hexagonal wurtzite structures.


1957 ◽  
Vol 1 ◽  
pp. 271-281
Author(s):  
Louis Silverman ◽  
William Houk ◽  
Lavada Moudy

AbstractThis paper outlines a rapid method for the determination of uranium dioxide in stainless steel by direct X-ray fluorescence analysis after chemical solution of the sample in perchloric acid. A scintillation counter is used to detect the intensity of the radiation. Modifications in the apparatus needed to insure stabilization of the counter are described. Strontium is used as internal indicator. The determination of uranium is unaffected by the presence of large amounts of iron, chromium or nickel at the dilutions described. The counting time for four pairs of counts (uranium and strontium) is about 12 minutes.A standard deviation corresponding to one-half to one per cent of the uranium dioxide present was observed on synthetic samples ranging from 15 to 25% uranium dioxide.


2011 ◽  
Vol 284-286 ◽  
pp. 781-785 ◽  
Author(s):  
Shi Cai Cui ◽  
Da Feng Zhang ◽  
Xi Peng Pu ◽  
Xian Hua Qian ◽  
Tian Tian Ge ◽  
...  

ZnO were rapidly synthesized using different zinc salts (Zn(NO3)2, Zn(CH3CO2)2, ZnCl2and ZnSO4) by an aqueous solution method at 90°C. The products were characterized by X-ray diffractometry and scanning electron microscopy. The results show that the anions have remarkable effects on the morphologies of ZnO. When Zn(NO3)2, Zn(CH3CO2)2or ZnCl2was used, ZnO was obtained with ellipsoidal, under-developed ellipsoidal and nano-particles morphologies, respectively. In the case of ZnSO4, layered basic zinc sulfate was obtained. The remarkable effects of anions on ZnO can be ascribed to the adsorption of the anions on the surface of ZnO, which hinders the further growth of ZnO nuclei. The effect of SO42-was further investigated by changing the mole ratio of SO42-to NO3-.


Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1458 ◽  
Author(s):  
Paola Semeraro ◽  
Simona Bettini ◽  
Shadi Sawalha ◽  
Sudipto Pal ◽  
Antonio Licciulli ◽  
...  

In recent years, the presence of numerous xenobiotic substances, such as antibiotics, has been detected in water environments. They can be considered as environmental contaminants, even if their effect on human health has yet to be totally understood. Several approaches have been studied for the removal of these kinds of pollutants. Among these compounds, tetracycline (TC), a broad-spectrum antibiotic, is one of the most commonly found in water due to its widespread use. In the context of reducing the presence of TC in aqueous solution, in this contribution, a composite catalyst based on zinc oxide (ZnO) and iron oxide (γ-Fe2O3) was developed and its photocatalytic properties were investigated. The catalytic materials were synthesized by a microwave-assisted aqueous solution method and characterized by Field Emission Scanning Electron Microscope (FESEM), X-Ray Fluorescence (XRF) and Brunauer−Emmett−Teller (BET) analysis. The TC concentration was evaluated by spectrophotometer measurements at specific time intervals. The performed photocatalytic experiments clearly demonstrated that the ZnO/γ-Fe2O3 composite catalyst presents significant photocatalytic activity, indeed a TC degradation efficiency of 88.52% was registered after 150 min. The presence of iron oxide in the structure of the catalyst enhances both the surface area and the pore volume, facilitating the adsorption of the analyte on the surface of nanostructures, a fundamental phase to optimize a photodegradation process. Moreover, ZnO was found to play the key role in the photocatalytic process assisted by γ-Fe2O3 which enhanced the TC degradation efficiency by 20%.


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