Papers by Keyword: Chemical Reduction

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Authors: Zhi Gang Wu
Abstract: Pure metallic nickel nanoparticles, spherical shape have been successfully synthesized by the chemical reduction of nickel chloride with hydrazine at room temperature without any protective agent and inert gas protection. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were employed to characterize the nickel nanoparticles and of course, the magnetic properties were also measured. This synthetic method is proven to be simple and very facile. And it’s very interesting that the obtained nickel nanoparticle can be isolated in solid states and stabilized for several months in atmosphere.
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Authors: S. Karthick Raja Namasivayam, Arul Maximus Rabel, Teena Abhraham
Abstract: In this present study, copper nanoparticles coated on the cotton fabrics was evaluated for the antibacterial property against bacterial strains isolated from post operative patients.In this study, CUNPs synthesized by chemical reduction method and the synthesized nanoparticles characterized by UV spectroscopy, energy dispersive X ray spectroscopy and further characterized for its size by SEM. CUNPs coated on the bleached cotton fabrics by pad dry cure method. Coating of CUNPs to cotton fabric conferred by SEM and FTIR. The coated fabrics were examined in the range of basic physical–mechanical parameters such as the tensile strength, the bursting strength and air permeability.Anti bacterial activity was determined against the clinical isolate of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa by agar diffusion assay. Copper nanoparticles synthesized by chemical reduction was primarly confirmed by the colour change of the reaction mixture from blue to olive green, plasmon absorption maxima at 600 nm and uniform sp
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Authors: Marco Giulietti, Marcelo Martins Seckler, Osnney José Bandeira Leite, Silas Derenzo
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Authors: Hong Yi Zhou, Si Liang, Si Si Zeng, Shuang Jian Lei
Abstract: Nitrate is a common groundwater contaminant and poses health and environmental threats. Reductive denitrification of nitrate by zero-valent iron was investigated in unbuffered solutions at 20 °C. Nitrate was effectively removed at low initial solution pH. The reaction was accompanied by the production and then disappearance of a small quantity of nitrite, suggesting that nitrite was the intermediate and subsequently further reduced. A rapid rise in solution pH was also observed during the reaction. At the initial pH of 4, a reduction of 90% in nitrate concentration from 60 to 7.0 mg/L at 60 min was observed. The extent of nitrate removal decreased with increasing solution pH within the tested range of 3 - 6, suggesting that the reaction was an acid-driven process. The extent of nitrate removal also increased with Fe dosage over the range of 5 - 20 g/L, as higher Fe dosages provided more reactive surfaces. It is proposed that protons participate in the nitrate reduction by Fe0 via an initial reduction of protons to reduced hydrogen species followed by a subsequent reaction with nitrate. The hydrolysis of Fe corrosion products (e.g., ferrous ions) produces protons, in particular, near the surfaces of Fe, which drives the reaction to continue.
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Abstract: Alloy nanostructures formed by magnetic and nonmagnetic components play a significant role in sensor applications due to their unique magnetic properties. In this study cobalt-silver nanomaterial has been synthesized by chemical reduction using sodium borohydride, though Co and Ag are immiscible according to their phase diagram. The materials prepared with different precursor compositions have been analysed to determine the structure and the magnetic properties. It is observed that the alloy samples show room temperature ferromagnetism. The surface morphology of the as prepared samples was studied from the SEM micrographs. This is a simple but an effective method to prepare magnetic Co-Ag nanomaterials in bulk quantities at room temperature.
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Authors: Ning Ding, Jin Gang Huang, Yue Wen, Qi Zhou, Yue Xu
Abstract: Azo dyes are extensively used in the industry, resulting in the large amount of wastewater. Redox mediators (R.M.) can accelerate the chemical reduction of azo dye by shuttling electrons from primary electron donors such as sulfide to azo dyes. Three different types of R.M. were studied on the enhancement of chemical reduction of Acid Orange 7. The electron shuttle ability of these types of R.M. with 2.5 mM of initial sulfide concentration at pH 7.5, either dissolved or undissolved type, followed in order by riboflavin, humic acid and activated carbon. The potential engineering application of these R.M. lie on the superior catalytic ability for riboflavin, wide existence in the environment for humic acid, and retaining in the bioreactors all the times for activated carbon.
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Authors: Yu Mei Gong, Na Zhao, Yi Wen Li, Shuai Zhang, Hong Zhang, Jing Guo
Abstract: A simple and non-toxic way was employed to fabricate electrical conductive TiO2 materials based on a chemical reduction process here. Glucose was selected as a reductant to reduce AgNO3 to obtain Ag-modified TiO2 nanoparticles. The properties of the nanoparticles were characterized by XRD, TEM, and fourpoint probe resistivity meter. The results show that the TiO2 was successfully modified by Ag nanoparticles, and the major crystalline phase of TiO2 in the Ag-modified TiO2 composite is anatase phase. The size of Ag increased with the AgNO3 concentration increasing. Compared with pure TiO2, the Ag modified TiO2 has a higher electrically conductive. In principle, it is expected to be a general and versatile approach to increase the conductivity of insulator or semiconductor.
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Authors: Xiao Yun Zhu, Zhong Cheng Guo
Abstract: Using reduced iron powder as raw material, Copper coated iron powder(CCIP) is prepared by electroless alkaline-based plating. We discuss the impacts of reductant concentration, plating solution temperature and main salt concentration on the properties of CCIP. Surface morphology and composition are studied by using scanning electron microscopy and X-ray diffraction. The results show that after coating, the iron powder surface is rougher and the copper layer is uniform in its simple metallic form without any oxide states.
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Authors: Rajasingam Ratnamalar, Mustapha Mariatti, Zulkifli Ahmad, Sharif Zein Sharif Hussein
Abstract: This work reports a simple chemical reduction route for the preparation of uniformed Ag nanoparticles whereby a fine control over the sizes of the Ag nanoparticles was studied by varying the concentrations of the reducing agents used. In characterization, UV-Vis spectroscopy showed the changes in optical properties of the Ag nanoparticles with regards to their sizes, where as the XRD patterns of the synthesized Ag nanoparticles confirmed the distinct peaks approximately at 2θ = 38.1°, 44.3°, 64.4°, 77.4°, and 81.5 representing Bragg’s reflections from (111), (200), (220), (311), and (222) planes of the face centred cubic lattice phase. This route of synthesis is feasible to produce Ag nanoparticles with diameters in the range of 30-45 nm.
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Authors: Jong Gwan Ahn, Dong Jin Kim, Hai Hoang, Jae Ryeong Lee, Hun Saeng Chung
Abstract: Ultra-fine copper powders with an average size of 150 nm were synthesized from Cu(OH)2 .H2O slurry with hydrazine monohydrate as a reduction agent by using the wet reduction method. Parameters such as temperature, reduction agent feeding rate, stirring rate, stirring speed, Cu(OH)2 concentration, and surfactants were investigated. It was found that the feeding rate of hydrazine monohydrate and the use of surfactants mainly affect the morphology and size of the copper powders along with their dispersion. XRD, PSA, and SEM were used to characterize the prepared particles.
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