Synthesis of Nano Metal Powder by Electrochemical Reduction of Iron Oxides

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.

Synthesis of Nano Metal Powder by Electrochemical Reduction of Metal Oxides

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.

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

2021 ◽  
Vol 53 (5) ◽  
pp. 210512
Author(s):  
Ade Utami Hapsari ◽  
Retna Deca Pravitasari ◽  
Hanif Yuliani ◽  
Damisih Damisih ◽  
Deni Shidqi Khaerudini ◽  
...  
Keyword(s):  
Room Temperature ◽  
Reduction Method ◽  
Intermetallic Phase ◽  
Reduction Process ◽  
Plateau Pressure ◽  
Synthesis Process ◽  
Optimal Method ◽  
Black Powder ◽  
Powder Samples ◽  
Precursor Powders

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%.

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

2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
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.

Performance of poly-o-phenylenediamine and its carbon dot composite electrode in the removal of Cu2+ from its aqueous solution

2021 ◽  
pp. 2151037
Author(s):  
Yu Meng ◽  
Qing Zhong ◽  
Arzugul Muslim
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Reduction ◽  
Composite Electrode ◽  
Reduction Process ◽  
Order Kinetic ◽  
Carbon Dot ◽  
First Order ◽  
Oxidation Reduction ◽  
Order Kinetic Model ◽  
Optimal Ph

Because −NH2 and −NH− in poly-[Formula: see text]-phenylenediamine (P[Formula: see text]PD) can interact strongly with the empty orbitals of Cu to show unique electrochemical activity, P[Formula: see text]PD is suitable for the removal of Cu[Formula: see text] by electrochemical oxidation–reduction process. In this study, with P[Formula: see text]PD and its carbon dot composite (CDs/P[Formula: see text]PD) as working electrodes, the electrochemical reduction and removal of Cu[Formula: see text] in the aqueous solution were carried out with the potentiostatic method. According to effects of voltage, pH of the solution, initial concentration of Cu[Formula: see text], and electrochemical reduction time on the Cu[Formula: see text] removal, the Cu[Formula: see text] removal ratios of P[Formula: see text]PD and CDs/P[Formula: see text]PD were up to 64.69% and 73.34%, respectively, at −0.2 V and the optimal pH. Additionally, results showed that these processes were in line with the quasi-first order kinetic model. Both P[Formula: see text]PD and CDs/P[Formula: see text]PD showed good reproducibility in six cycles. After five times of repeated usage, the regeneration efficiencies of P[Formula: see text]PD and CDs/P[Formula: see text]PD dropped to 77.04% and 79.36%, respectively.

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

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.

Electrochemical reduction of nitrobenzene and 4-nitrophenol in the room temperature ionic liquid [C4dmim][N(Tf)2]

2006 ◽  
Vol 596 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Debbie S. Silvester ◽  
Andrew J. Wain ◽  
Leigh Aldous ◽  
Christopher Hardacre ◽  
Richard G. Compton
Keyword(s):  
Ionic Liquid ◽  
Electrochemical Reduction ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid

Electrochemical reduction of indigo by combination of sodium borohydride and copper salt

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaoyan Li ◽  
MengQian Wang ◽  
Gang Wu ◽  
Jiming Yao
Keyword(s):  
Sodium Borohydride ◽  
Room Temperature ◽  
Reduction Potential ◽  
Copper Ion ◽  
Reduction Process ◽  
Divalent Copper ◽  
Content Type ◽  
Copper Sulfate Pentahydrate ◽  
Electrochemical Technology ◽  
Dyed Fabric

Purpose The purpose of this study is to improve the performance of sodium borohydride in reducing indigo at room temperature, the divalent copper ion complex was combined with electrochemical technology for the reduction of indigo by sodium borohydride. Design/methodology/approach According to the K/S value of the dyed cloth sample, find a more suitable ligand for the copper ion in the catholyte. Response surface analysis tests were performed to evaluate the effects of sodium borohydride concentration, sodium hydroxide concentration and copper sulfate pentahydrate concentration on the reduction potential of the dye solution and the K/S value of the dyed fabric samples. Findings Sodium gluconate was found to be a more suitable ligand for copper ions in catholyte. The effects of NaOH concentration as well as the interaction of NaBH4 and NaOH on the reduction potential of the catholyte and the K/S value of the dyed fabric samples were extremely significant. The optimal concentrations of NaBH4, NaOH and CuSO4•5H2O were 0.5, 2.5 and 0.65 g/L. In the case of the optimized condition, the absolute value of the reduction potential was 968, and the K/S value was 11.92, which is comparable with that of the conventional reduction process with sodium dithionite. Originality/value The divalent copper ion complex combined with electrochemical technology was applied in the process of reducing indigo with NaBH4 at room temperature.

scholarly journals Recovery of Iron, Chromium, and Nickel from Pickling Sludge Using Smelting Reduction

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 936 ◽  
Author(s):  
Zhaohui Tang ◽  
Xueyong Ding ◽  
Xinlin Yan ◽  
Yue Dong ◽  
Chenghong Liu
Keyword(s):  
Reduction Process ◽  
Slag Basicity ◽  
Experimental Results ◽  
Iron Ores ◽  
Reduction Temperature ◽  
Smelting Reduction ◽  
Reduction Time ◽  
Temperature Reduction ◽  
Pickling Sludge ◽  
Iron Chromium

This paper reports the recoveries of iron, chromium, and nickel from pickling sludge using coal-based smelting reduction. The influences of slag basicity (CaO/SiO2, which is controlled by high phosphorus oolitic hematite iron ores), reduction temperature, reduction time, and the C/O mole ratio on the recoveries of Fe, Cr, and Ni are investigated systematically. The experimental results show that high recoveries of Fe (98.91%), Cr (98.46%), and Ni (99.44%) are produced from pickling sludge with optimized parameters for the smelting reduction process. The optimized parameters are a slag basicity of 1.5; a reduction temperature of 1550 °C, a reduction time of 90 min, and a C/O mole ratio of 2.0. These parameters can be used as technical support for the recycling of pickling sludge with pyrometallurgy.

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