Effect of Dissolution Temperature on Purity of LaNi5 Powder Synthesized with the Combustion-Reduction Method

The LaNi5 intermetallic phase has been extensively investigated because of its excellent properties, such as attractive hydrogen storage, medium plateau pressure, and easy activation. LaNi5 phase is generally produced by a complicated method, which involves several steps, i.e. melting, alloying, casting, softening and making them into powder. This study aimed to develop a new LaNi5 synthesis process by modifying the combustion-reduction method. In this method it is very important to produce La2NiO4, because LaNi5 is formed from the process of reducing this phase. The precursor powders La(NO3)3.6H2O and Ni(NO3)2.6H2O were reacted with distilled water as a solvent medium and mixed using magnetic stirring. The synthesis process was carried out at room temperature, 60 °C, 70 °C, and 80 °C for 10 minutes until the solution became transparent green. The solution was then dried for 2 hours at 100 °C to form a transparent green gel. The gel was calcined at a temperature of 500 °C for 2 hours, producing a black powder. The optimal black powder was then reduced using CO gas at 600 °C for 2 hours. The powder samples were characterized using XRD, FTIR, and SEM-EDX. The analysis revealed that synthesis at room temperature was the most optimal method for the reduction process because it produced the most La2NiO4, at 12.135 wt%.

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Synthesis of Nano Metal Powder by Electrochemical Reduction of Iron Oxides

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.137 ◽

2007 ◽

Vol 534-536 ◽

pp. 137-140

Author(s):

Ki Hun Seong ◽

Jai Sung Lee

Keyword(s):

Electrochemical Reduction ◽

Applied Voltage ◽

Room Temperature ◽

Equilibrium Shape ◽

Reduction Process ◽

Particle Growth ◽

Phase Evolution ◽

Reduction Time ◽

Powder Samples ◽

Nano Metal Powder

Synthesis of iron nanopowder by room-temperature electrochemical reduction process of α-Fe2O3 nanopowder was investigated in terms of phase evolution and microstructure. As process variables, reduction time and applied voltage were changed in the range of 1~20 h and 30~40 V, respectively. From XRD analyses, it was found that volume of Fe phase increased with increasing reduction time and applied voltage, respectively. The crystallite size of Fe phase in all powder samples was less than 30 nm, implying that particle growth was inhibited by the reaction at room temperature. Based on the distinct equilibrium shape of crystalline particle, phase composition of nanoparticles was identified by TEM observation.

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Synthesis of Nano Metal Powder by Electrochemical Reduction of Metal Oxides

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.1137 ◽

2004 ◽

Vol 449-452 ◽

pp. 1137-1140

Author(s):

Kyung Jong Lee ◽

Jai Sung Lee

Keyword(s):

Particle Size ◽

Electrochemical Reduction ◽

Room Temperature ◽

Reduction Method ◽

Reduction Process ◽

Powder Particle Size ◽

Material Transport ◽

Powder Characteristics ◽

Nano Metal Powder ◽

Reduction Of Metal Oxides

This work has attempted to find a new low temperature reduction process for fabrication of Cu nanopowder from fine CuO powder. For this purpose, we used electrochemical reduction method which is conducted in an electrolyte of NaCl aqueous solution at room temperature. It was found that ball-milled CuO powder (particle size ~100 nm and grain size ~40 nm) was completely reduced under the conditions of 20 V power, 0.5 mol NaCl solution and 2 h reaction time, producing Cu nanopowder (particle size ~80 nm and crystallite size ~25 nm). Simultaneously, we observed that sintering of nanopowders occurred during the reduction process, leading to agglomeration of nanopowder. Based upon the experimental results, the correlation between electrochemical reduction process and its related powder characteristics was discussed in terms of material transport.

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Enhancement of Photocatalytic Performance of Anatase by Silver Deposition through Chemical Reduction Process at Room Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.998.71 ◽

2020 ◽

Vol 998 ◽

pp. 71-77

Author(s):

Tanaporn Narkbuakaew ◽

Pornapa Sujaridworakul

Keyword(s):

Rhodamine B ◽

Room Temperature ◽

Photocatalytic Performance ◽

Reduction Method ◽

Chemical Reduction ◽

Organic Pollutant ◽

Reduction Process ◽

Chemical Reduction Method ◽

Silver Deposition ◽

Environmental Application

Herein, Ag-anatase photocatalysts were synthesized though chemical reduction method under room temperature by using PVP and NaBH4 as stabilizer and strong reducing agent, respectively. The prepared photocatalysts were characterized by the following technique: XRD, SEM, HR-TEM, EDX, and UV-Vis-NIR. The photocatalytic performance of 0.05 g of photocatalysts were performed under UV irradiation within 1 h by using 10 mg/L of rhodamine B as the representative of organic pollutant. The results demonstrated that the optimum Ag loading contents were 2 %wt (2-ST) which can degrade rhodamine B up to 98.54%. Therefore, the photocatalytic performance of bare anatase could be enhanced by deposited Ag nanoparticles. Further, this prepared Ag-anatase could be suitable for environmental application.

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Green synthesis of mixed metallic nanoparticles using room temperature self-assembly

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v13i2.5942 ◽

2017 ◽

Vol 13 (2) ◽

pp. 4671-4677 ◽

Cited By ~ 2

Author(s):

A. M. Abdelghany ◽

A.H. Oraby ◽

Awatif A Hindi ◽

Doaa M El-Nagar ◽

Fathia S Alhakami

Keyword(s):

Self Assembly ◽

Metallic Nanoparticles ◽

Room Temperature ◽

Bimetallic Nanoparticles ◽

Reduction Process ◽

Nano Particles ◽

Nano Structure ◽

Small Shift ◽

Molar Ratios ◽

Vis Spectroscopy

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.

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The Extrusion and SPS of Zirconium–Copper Powders and Studies of Selected Mechanical Properties

Materials ◽

10.3390/ma14133560 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3560

Author(s):

Tomasz Skrzekut ◽

Grzegorz Boczkal ◽

Adam Zwoliński ◽

Piotr Noga ◽

Lucyna Jaworska ◽

...

Keyword(s):

Mechanical Properties ◽

Intermetallic Compounds ◽

Room Temperature ◽

Intermetallic Phase ◽

Extrusion Process ◽

Strength Properties ◽

Plasma Sintering ◽

Copper Powders ◽

Spark Plasma ◽

Zirconium Copper

Zr-2.5Cu and Zr-10Cu powder mixtures were consolidated in the extrusion process and using the spark plasma sintering technique. In these studies, material tests were carried out in the fields of phase composition, microstructure, hardness and tensile strength for Zr-Cu materials at room temperature (RT) and 400 °C. Fractography analysis of materials at room temperature and 400 °C was carried out. The research took into account the anisotropy of the materials obtained in the extrusion process. For the nonequilibrium SPS process, ZrCu2 and Cu10Zr7 intermetallic compounds formed in the material at sintering temperature. Extruded materials were composed mainly of α-Zr and ZrCu2. The presence of intermetallic compounds affected the reduction in the strength properties of the tested materials. The highest strength value of 205 MPa was obtained for the extruded Zr-2.5Cu, for which the samples were cut in the direction of extrusion. For materials with 10 wt.% copper, more participation of the intermetallic phase was formed, which lowered the mechanical properties of the obtained materials. In addition to brittle intermetallic phases, the materials were characterized by residual porosity, which also reduced the strength properties.

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ZnO/RGO Heterojunction Based near Room Temperature Alcohol SENSOR with Improved Efficiency

Engineering Proceedings ◽

10.3390/i3s2021dresden-10073 ◽

2021 ◽

Vol 6 (1) ◽

pp. 25

Author(s):

Sanghamitra Ghosal ◽

Partha Bhattacharyya

Keyword(s):

Active Sites ◽

Room Temperature ◽

Surface Engineering ◽

Gas Sensing ◽

Energy Band Diagram ◽

Future Generation ◽

High Yield ◽

Synthesis Process ◽

Ethanol Sensor ◽

Vapor Sensing

The systematic optimization of surface engineering (dimensionality) indeed plays a crucial role in achieving efficient vapor-sensing performance. Among various semiconducting metal oxides, owing to some of its unique features and advantages, ZnO has attracted researchers on a global scale due to its application in various fields, including chemical sensors. The concomitant optimization of the surface attributes (varying different dimensions) of ZnO have become a sensation for the entire research community. Moreover, the small thickness and extremely large surface of exfoliated 2D nanosheets render the gas sensing material an ideal candidate for achieving strong coupling with different gas molecules. However, temperature is a crucial factor in the field of chemical sensing. Recently, graphene-based gas sensors have attracted attention due to their variety of structures, unique sensing performances and room temperature working conditions. In this work, a highly sensitive and fast responsive low temperature (60 °C)-based ethanol sensor, based on RGO/2D ZnO nanosheets hybrid structure, is reported. After detailed characterizations, the vapor sensing potentiality of this sensor was tested for the detection of ethanol. The ethanol sensor offered the response magnitude of 89% (100 ppm concentration) with response and recovery time of 12 s/29 s, respectively. Due to excessively high number of active sites for VOC interaction, with high yield synthesis process and appreciably high carrier mobility, this has paved the way for developing future generation, miniaturized and flexible (wearable) vapor sensor devices, meeting the multidimensional requirements for traditional and upcoming (health/medical sector) applications. The underlying mechanistic framework for vapor sensing, using this hybrid junction, is explained with the Energy Band Diagram.

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Compression of Single-Crystal Micropillars of the Γ Intermetallic Phase in the Fe-Zn System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.922.264 ◽

2014 ◽

Vol 922 ◽

pp. 264-269 ◽

Cited By ~ 7

Author(s):

Masahiro Inomoto ◽

Norihiko L. Okamoto ◽

Haruyuki Inui

Keyword(s):

Single Crystal ◽

Deformation Behavior ◽

Room Temperature ◽

Focused Ion Beam ◽

Ion Beam ◽

Intermetallic Phase ◽

Gamma Phase ◽

Compression Tests ◽

Slip Direction ◽

Beam Method

The deformation behavior of the Γ (gamma) phase in the Fe-Zn system has been investigated via room-temperature compression tests of single-crystal micropillar specimens fabricated by the focused ion beam method. Trace analysis of slip lines indicates that {110} slip occurs for the specimens investigated in the present study. Although the slip direction has not been uniquely determined, the slip direction might be <111> in consideration of the crystal structure of the Γ phase (bcc).

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A Novel Photosynthesis of Carboxymethyl Starch-Stabilized Silver Nanoparticles

The Scientific World JOURNAL ◽

10.1155/2014/514563 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 8

Author(s):

M. A. El-Sheikh

Keyword(s):

Silver Nanoparticles ◽

Room Temperature ◽

Colloidal Solution ◽

Synthesis Method ◽

Silver Ions ◽

Water Soluble ◽

Synthesis Process ◽

Carboxymethyl Starch ◽

Round Shape ◽

First Time

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40°C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25°C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1–21 nm and the highest counts % of these particles were for particles of 6–10 and 1–3 nm, respectively.

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STRUCTURE AND MAGNETIC PROPERTIES OF MECHANICAL ALLOYED Mn-15at.%Al

International Journal of Nanoscience ◽

10.1142/s0219581x13500063 ◽

2013 ◽

Vol 12 (01) ◽

pp. 1350006

Author(s):

AHMED E. HANNORA ◽

FARIED F. HANNA ◽

LOTFY K. MAREI

Keyword(s):

Thermal Analysis ◽

Room Temperature ◽

Average Crystallite Size ◽

Al Alloy ◽

X Ray Diffraction ◽

X Ray ◽

Milled Sample ◽

Powder Samples ◽

Xrd Patterns ◽

Method Analysis

Mechanical alloying (MA) method has been used to produce nanocrystallite Mn -15at.% Al alloy. X-ray diffraction (XRD) patterns for the as-milled elemental α- Mn and aluminum powder samples show a mixture of α + β- MnAl phases after 20 h of milling and changes to a dominant β- MnAl phase structure after 50 h. An average crystallite size of 40 nm was determined from Hall–Williamson method analysis after 5 h of milling. Moreover, the thermal analysis results using differential thermal analysis (DTA), suggested a possible phase transformation after 20 h of milling. Isothermal treatments are carried in the temperature range of 450°C to 1000°C. Room-temperature vibrating sample magnetometer (VSM) measurements of the hysteretic response revealed that the saturation magnetization Bs and coercivity Hc for 10 h ball milled sample are ~ 2.1 emu/g and ~ 92 Oe, respectively.

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