Effect of pH on Nanoparticle Structure in Radiochemical Synthesis of PtCu Alloy Supported on γ-Fe2O3 and Carbon

MRS Advances ◽  
2016 ◽  
Vol 1 (6) ◽  
pp. 427-432 ◽  
Author(s):  
Tomohisa Okazaki ◽  
Satoshi Seino ◽  
Junichiro Kugai ◽  
Yuji Ohkubo ◽  
Takashi Nakagawa ◽  
...  

ABSTRACTPtCu nanoparticles were synthesized with different pH and support conditions using radiochemical process. The nanoparticle structures were characterized by transmission electron microscopy, inductively coupled plasma atomic emission spectrometry, X-ray absorption spectroscopy, and X-ray diffraction techniques. The nanoparticle structure was relevant to the pH of the precursor solutions. The lattice parameter of PtCu alloy increased in high pH samples, which indicates the critical effect of metal ion adsorption in precursor solution on nanoparticle structure.

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 133
Author(s):  
Henryk R. Parzentny ◽  
Leokadia Róg

It is supposed that the determination of the content and the mode of occurrence of ecotoxic elements (EE) in feed coal play the most significant role in forecasting distribution of EE in the soil and plants in the vicinity of power stations. Hence, the aim of the work was to analyze the properties of the feed coal, the combustion residues, and the topsoil which are reached by EE together with dust from power stations. The mineral and organic phases, which are the main hosts of EE, were identified by microscopy, X-ray powder diffraction, inductively coupled plasma atomic emission spectrometry, and scanning electron microscope with an energy dispersive X-ray methods. The highest content of elements was observed in the Oi and Oe subhorizons of the topsoil. Their hosts are various types of microspheres and char, emitted by power stations. In the areas of long-term industrial activity, there are also sharp-edged grains of magnetite emitted in the past by zinc, lead, and ironworks. The enrichment of the topsoil with these elements resulted in the increase in the content of EE, by between 0.2 times for Co; and 41.0 times for Cd in the roots of Scots pine, common oak and undergrowth, especially in the rhizodermis and the primary cortex and, more seldom, in the axle roller and cortex cells.


Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 138
Author(s):  
Yunfei Shangguan ◽  
Xinguo Zhuang ◽  
Jing Li ◽  
Baoqing Li ◽  
Xavier Querol ◽  
...  

Coal as the source of critical elements has attracted much attention and the enrichment mechanisms are of significant importance. This paper has an opportunity to investigate the mineralogical and geochemical characteristics of the Permian and Jurassic bituminous coals and associated non-coals from two underground coal mines in the Shanbei Coalfield (Northeast Ordos basin), Shaanxi Province, North China, based on the analysis of X-ray diffraction (XRD), inductively coupled plasma atomic-emission spectrometry (ICP-AES/MS), and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). The Jurassic and Permian coals have similar chemical features excluding ash yield, which is significantly higher in the Permian coals. Major mineral matters in the Jurassic coals are quartz, kaolinite, and calcite. By contrast, mineral assemblages of the Permian coals are dominated by kaolinite; and apatite occurring in the middle section’s partings. The Jurassic coals are only enriched in B, whereas the Permian coals are enriched in some trace elements (e.g., Nb, Ta, Th, and REY). Boron has a mixed inorganic and organic association which may be absorbed by organic matter from fluid (or groundwater) or inherited from coal-forming plants. Additionally, climatic variation also plays an important role. As for the Permian coals, kaolinite and apatite as the major carriers of elevated elements; the former were derived from the sedimentary source region (the Yinshan Oldland and the Benxi formation) and later precipitated from Ca-, and P-rich solutions. We deduced that those elevated elements may be controlled by the source rock and diagenetic fluid input. The findings of this work offered new data to figure out the mechanism of trace element enrichment of coal in the Ordos basin.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Shanjun Chen ◽  
Yan Chen ◽  
Huafeng Zhang ◽  
Yongjian Tang ◽  
Jianjun Wei ◽  
...  

A novel bulk synthesis method for preparing high pure Ti3Al nanoparticles was developed by flow-levitation method (FL). The Ti and Al vapours ascending from the high temperature levitated droplet were condensed by cryogenic Ar gas under atmospheric pressure. The morphology, crystalline structure, and chemical composition of Ti3Al nanoparticles were, respectively, investigated by transmission electron microscopy, X-ray diffraction, and inductively coupled plasma atomic emission spectrometry. The results indicated that the Ti3Al powders are nearly spherical-shaped, and the particle size ranges from several nanometers to 100 nm in diameter. Measurements of the d-spacing from X-ray (XRD) and electron diffraction studies confirmed that the Ti3Al nanoparticles have a hexagonal structure. A thin oxidation coating of 2-3 nm in thickness was formed around the particles after exposure to air. Based on the XPS measurements, the surface coating of the Ti3Al nanoparticles is a mixture of Al2O3and TiO2. The production rate of Ti3Al nanoparticles was estimated to be about 3 g/h. This method has a great potential in mass production of Ti3Al nanoparticles.


2016 ◽  
Vol 1 (1) ◽  
pp. 30 ◽  
Author(s):  
Honghong Chen ◽  
Hui Wang ◽  
Tongtong Wang ◽  
Songren Huang ◽  
Xiaoxia Zang ◽  
...  

Chlorothalonil hydrolytic dehalogenase (Chd) is one of two reported hydrolytic dehalogenases for halogenated aromatics, and its catalysis is independent of coenzyme A and ATP. Earlier studies have established that the catalytic activity of Chd requires zinc ions. In this study, the metal center of Chd was systematically investigated. The metal content of Chd was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES), and there were 2.14 equivalents of zinc/mol of protein, indicating that Chd contains a binuclear (Zn2+-Zn2+) center. It was found that other divalent cations, such as cobalt (Co2+) and cadmium (Cd2+), could substitute zinc (Zn2+) leading to relative activities of 91.6% and 120.0%, whereas manganese (Mn2+) and calcium (Ca2+) could substitute Zn2+ leading to relative activities of 29.1% and 57.0%, respectively. The enzymatic properties of these different metal ion-substituted Chd variants were also compared. Error-prone PCR and DNA shuffling methods were applied to directly evolve Chd to generate variants with higher catalytic efficiencies of chlorothalonil. Enhanced Chd variants were selected based on the formation of clear haloes on Luria-Bertani plates supplemented with chlorothalonil. One variant, Q146R/N168Y/S303G, exhibited a 4.43-fold increase in catalytic efficiency, showing the potential for application in the dehalogenation and detoxification of chlorothalonil contaminated-sites.


2013 ◽  
Vol 737 ◽  
pp. 145-152 ◽  
Author(s):  
Nurul Aini Edama ◽  
Alawi Sulaiman ◽  
Ku Halim Ku Hamid ◽  
Miradatul Najwa Mohd Rodhi ◽  
Mohibbah Musa ◽  
...  

This study was conducted to characterize Sg. Sayong clay so that it can be applied as a supporting material for the immobilization of biocatalyst in the bioconversion of wastewater into biofuel. The clay sample was physically and chemically characterized using Nitrogen Adsorption, X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and Field Emission Scanning Electron Microscopy (FESEM). The results obtained showed that the clay composed of SiO2 (57.4%), followed by Al2O3 (32.5%), K2O (4.9%), Fe2O3 (3.8%) and traces amount of Ca, Mg, Ma, and Ti. The results also showed the clay type was kaolinite with some presence of quartz, illite, montmorillonite and microcline. The clay was also successfully coated onto the wire-mesh and immobilized with biocatalyst for further bioconversion study.


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