scholarly journals Reconstruction of Copper Nanoparticles at Electrochemical CO 2 Reduction Reaction Conditions Occurs via Two‐step Dissolution/Redeposition Mechanism

2021 ◽  
Author(s):  
Stefan Popovic ◽  
Marjan Bele ◽  
Nejc Hodnik
Keyword(s):  
Copper Nanoparticles ◽  
Reduction Reaction ◽  
Reaction Conditions

scholarly journals Green Synthesis of Copper Nanoparticles Using Cotton

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1906
Author(s):  
Marissa Pérez-Alvarez ◽  
Gregorio Cadenas-Pliego ◽  
Odilia Pérez-Camacho ◽  
Víctor E. Comparán-Padilla ◽  
Christian J. Cabello-Alvarado ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Copper Nanoparticles ◽  
Uv Spectroscopy ◽  
Synthesis Method ◽  
Crystallinity Index ◽  
Reaction Conditions ◽  
New Synthesis ◽  
Water As Solvent ◽  
Characterization Studies ◽  
Xrd Patterns

Copper nanoparticles (CuNP) were obtained by a green synthesis method using cotton textile fibers and water as solvent, avoiding the use of toxic reducing agents. The new synthesis method is environmentally friendly, inexpensive, and can be implemented on a larger scale. This method showed the cellulose capacity as a reducing and stabilizing agent for synthetizing Cellulose–Copper nanoparticles (CCuNP). Nanocomposites based on CCuNP were characterized by XRD, TGA, FTIR and DSC. Functional groups present in the CCuNP were identified by FTIR analysis, and XRD patterns disclosed that nanoparticles correspond to pure metallic Cu°, and their sizes are at a range of 13–35 nm. Results demonstrated that CuNPs produced by the new method were homogeneously distributed on the entire surface of the textile fiber, obtaining CCuNP nanocomposites with different copper wt%. Thus, CuNPs obtained by this method are very stable to oxidation and can be stored for months. Characterization studies disclose that the cellulose crystallinity index (CI) is modified in relation to the reaction conditions, and its chemical structure is destroyed when nanocomposites with high copper contents are synthesized. The formation of CuO nanoparticles was confirmed as a by-product, through UV spectroscopy, in the absorbance range of 300–350 nm.

Durability study of platinum nanoparticles supported on gas-phase synthesized graphene in oxygen reduction reaction conditions

2019 ◽  
Vol 467-468 ◽  
pp. 1181-1186 ◽  
Author(s):  
Erwan Bertin ◽  
Adrian Münzer ◽  
Sven Reichenberger ◽  
Rene Streubel ◽  
Thomas Vinnay ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Gas Phase ◽  
Platinum Nanoparticles ◽  
Reduction Reaction ◽  
Reaction Conditions

Preliminary Study on the Removal of Hexavalent Chromium in Wastewater with Reduction of Sulfur Dioxide

2013 ◽  
Vol 864-867 ◽  
pp. 1699-1703
Author(s):  
Ji Ming Wu ◽  
Sheng Gao Cheng
Keyword(s):  
Reaction Time ◽  
Sulfur Dioxide ◽  
Hexavalent Chromium ◽  
Reduction Reaction ◽  
High Concentration ◽  
Reaction Conditions ◽  
Ph Values ◽  
Different Temperatures ◽  
Preliminary Study ◽  
High Concentrations

The paper focused on a self-developed methodology through using sulfur dioxide to deal with high concentration of chromium-containing wastewater. It studied the effects of different pH values, different reaction time, different temperatures and different amounts of sulfur with sulfur dioxide reduction reaction on the chromium-containing wastewater. The results showed that: when the reaction conditions were controlled as follows: the pH values ranged from 2 to 4, the reaction temperature was controlled 40~60°C, the amount of sulfur in theoretical was 1.2 times and the reaction time was 40 min, the hexavalent chromium in the high concentrations of chromium-containing wastewater could be effectively removed.

scholarly journals Synthesis and Catalytic Applications of Ultrasmall Copper Nanoparticles Using Aloe Vera Plant Extract

2020 ◽  
Author(s):  
Rajagopal Ramkumar ◽  
Shradha Sapru ◽  
Panthalattu Parambil Archana
Keyword(s):  
Catalytic Activity ◽  
Copper Nanoparticles ◽  
Plant Extract ◽  
Aloe Vera ◽  
Catalyst Loading ◽  
Water Medium ◽  
Reaction Conditions ◽  
Three Component Reaction ◽  
Catalytic Applications ◽  
Low Catalyst Loading

<div>An extract of <i>Aloe Vera</i> acts as a powerful reducing agent for the synthesis of ultrasmall copper nanoparticles (CuNPs) in water medium. The prepared copper nanoparticles are characterized by XRD, HRTEM and UV-Vis analysis. The diameter of the prepared nanoparticle is less than 5 nm. The catalytic activity of CuNPs has been successfully evaluated for the three-component reaction to synthesize 1,2,3-triazoles and chalcone tethered 1,2,3-triazoles with low catalyst loading and under mild reaction conditions. These triazoles are further utilized for the synthesis of dihydropyrazines.</div>

scholarly journals Preparation of Metal Oxides Containing ppm Levels of Pd as Catalysts for the Reduction of Nitroarene and Evaluation of Their Catalytic Activity by the Fluorescence-Based High-Throughput Screening Method

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 542
Author(s):  
Taeho Lim ◽  
Min Su Han
Keyword(s):  
Catalytic Activity ◽  
Metal Oxides ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening Method ◽  
Reduction Reaction ◽  
Precipitation Method ◽  
Reaction Conditions ◽  
One Pot ◽  
Co Precipitation

Herein, an easily accessible and efficient green method for the reduction of nitroarene compounds was developed using metal oxide catalysts. Heterogeneous metal oxides with or without Pd were prepared by a simple and scalable co-precipitation method and used for the reduction of nitroarenes. A fluorescence-based high-throughput screening (HTS) method was also developed for the rapid analysis of the reaction conditions. The catalytic activity of the metal oxides and reaction conditions were rapidly screened by the fluorescence-based HTS method, and Pd/CuO showed the highest catalytic activity under mild reaction conditions. After identifying the optimal reaction conditions, various nitroarenes were reduced to the corresponding aniline derivatives by Pd/CuO (0.005 mol% of Pd) under these conditions. Furthermore, the Pd/CuO catalyst was used for the one-pot Suzuki–Miyaura cross-coupling/reduction reaction. A gram-scale reaction (20 mmol) was successfully performed using the present method, and Pd/CuO showed high reusability without a loss of catalytic activity for five cycles.

Kinetic Mechanism on Synthesis of Copper Nanoparticle from Reduction Reaction - Effect of Temperature

2015 ◽  
Vol 754-755 ◽  
pp. 1012-1016
Author(s):  
Noorsuhana Mohd Yusof ◽  
Junaidah Jai ◽  
Ahmad Hafizie Zaini ◽  
Nur Hashimah Alias ◽  
Nurul Aimi Ghazali ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Room Temperature ◽  
Low Cost ◽  
Copper Nitrate ◽  
Kinetic Mechanism ◽  
Reduction Reaction ◽  
Reducing Agent ◽  
Effect Of Temperature ◽  
Hydroxyl Groups ◽  
Copper Nanoparticle

Copper nanoparticles, due to their interesting properties, low cost preparation and many potential applications in catalysis, cooling fluid or conductive inks, have attracted a lot of interest in recent years. In this study, copper nanoparticles were synthesized through the palm leaves extract that act as reducing agent. In this synthesis route, the hydroxyl groups of the polyphenols in palm extract are capable to act as reducing agent for reduction reaction. The effect of temperature given starting with control parameters at room temperature proceeds to 40, 50, 60, 70 and 80°C with the time length of 2 hours and 10 milimol copper nitrate aqueous solution. Characterization had been conducted using the instrument of UV-vis spectrophotometer, FTIR and ESEM. The average size of all powder nanoparticles was found to 109, 86, 196, 133, 241, and 230nm accordingly from room temperature till 80°C. The correspondence analysis of the results yielded that the optimum temperature was at 40°C which is 86nm of average copper nanoparticle size.

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