scholarly journals Electrodeposition of Cu-Mn Films as Precursor Alloys for the Synthesis of Nanoporous Cu

Electrochem ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 520-533
Author(s):  
Ezer Castillo ◽  
Nikolay Dimitrov
Keyword(s):  
Metal Ion ◽  
Reduction Potential ◽  
Type I ◽  
X Ray ◽  
Ion Concentrations ◽  
Galvanostatic Deposition ◽  
Anodic Stripping ◽  
Voltammetric Studies ◽  
Current Densities ◽  
Scanning Electron

Cu-Mn alloy films are electrodeposited on Au substrates as precursor alloys for the synthesis of fine-structured nanoporous Cu structures. The alloys are deposited galvanostatically in a solution containing ammonium sulfate, (NH4)2SO4, which serves as a source of the ammine ligand that complexes with Cu, thereby decreasing the inherent standard reduction potential difference between Cu and Mn. The formation of the [Cu(NH3)n]2+ complex was confirmed by UV-Vis spectroscopic and voltammetric studies. Galvanostatic deposition at current densities ranging from 100 to 200 mA⋅cm−2 generally resulted in the formation of type I, crystalline coatings as revealed by scanning electron microscopy. Although the deposition current efficiency is (<30%) generally low, the atomic composition (determined by energy dispersive X-ray spectroscopy) of the deposited alloys range from 70–85 at% Mn, which is controlled by simply adjusting the ratio of the metal ion concentrations in the deposition bath. Anodic stripping characterization revealed a three-stage dissolution of the deposited alloys, which suggests control over the selective removal of Mn. The composition of the alloys obtained in the studies are ideal for electrochemical dealloying to form nanoporous Cu.

scholarly journals X-Ray Diffraction and SEM Investigation of Solidification/ Stabilization of Nickel and Chromium Using Fly ash

2011 ◽  
Vol 8 (s1) ◽  
pp. S395-S403 ◽  
Author(s):  
Ranjana A. Patil ◽  
Sangesh P. Zodape
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Fly Ash ◽  
Metal Ion ◽  
X Ray Diffraction ◽  
Main Thrust ◽  
X Ray ◽  
Xrd Studies ◽  
Sem Investigation ◽  
Scanning Electron

The main thrust of the paper is mechanism of immobilization of nickel(Ni) and chromium(Cr) metal sludge by solidification/stabilization using lime fly ash and sand (LFAS). The mineralogy of fly ash used for the study has been determined on the basis of x- ray diffraction analysis (XRD). Attempts have been made to investigate the consequences of interaction of heavy metal ion with constituents of lime fly ash sand composite on the basis of XRD studies and scanning electron microscopy (SEM, except chromium).

Micro Experimental Research on Cement Stone under Sulfate Erosion

2012 ◽  
Vol 588-589 ◽  
pp. 95-103
Author(s):  
Jue Zhu ◽  
Qian Chen ◽  
Yuan Yuan Ding
Keyword(s):  
Immersion Time ◽  
Sulfate Solution ◽  
Cement Stone ◽  
Erosion Product ◽  
Sulfate Ion ◽  
Cement Ratio ◽  
X Ray ◽  
Ion Concentrations ◽  
Scanning Electron ◽  
Xrd Method

In this article, micro investigation of the cement stone under sulfate erosion is carried out by using SEM (Scanning Electron Microscope). The XRD method is also employed to semi-quantitatively analyze the erosion product. The cement stones whose water-cement is 0.45, 0.55, 0.65, respectively, immersed in sulfate solution whose sulfate ion concentrations is 0%, 3%, 4%, 5%, 6%. After different immersion time of 24 days, 45 days and 60 days, the microstructure of samples is detect by the SEM. The energy-dispersive X-ray analysis (EDX) is taken to determine the general elements in samples. The XRD method is employed to semi-quantitatively determine the weight percents of ettringite and gypsum in cement stone samples. Through comparative analysis, it tries to point out how the sulfate ion and water-cement ratio will affect the erosion products.

PRAPARATION AND CHARACTERISATION OF TiO2 NANOTUBULAR ARRAYS FOR ELECTRO-OXIDATION OF ORGANIC COMPOUNDS: EFFECT OF IMMOBILIZATION OF THE NOBLE METAL PARTICLES

2012 ◽  
Vol 05 ◽  
pp. 41-48 ◽  
Author(s):  
MIRGHASEM HOSSEINI ◽  
MOHAMAD MOHSEN MOMENI
Keyword(s):  
Organic Compounds ◽  
Noble Metal ◽  
Surface Characteristics ◽  
Metal Particles ◽  
X Ray ◽  
Galvanostatic Deposition ◽  
Oxidation Of Organic Compounds ◽  
Electro Oxidation ◽  
Nanoporous Layer ◽  
Scanning Electron

The morphology, composition and the electrochemical behavior of the anodic nanoporous layer, prepared by the galvanostatic anodisation of titanium, followed by galvanostatic deposition of noble metal particles have been investigated. The morphology and surface characteristics of result electrodes were investigated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. The results indicated that noble metal particles were homogeneously deposited on the surface of TiO 2 nanotubes. The nanotubular TiO 2 layers consist of individual tubes of about 40-80 nm diameters. The electrocatalytic behavior of result electrodes for electro-oxidation of organic compounds (glucose, dopamine, ascorbic acid and hydrazine) was studied by cyclic voltammetry. The results showed that the result electrodes possess catalytic activity toward the oxidation organic compounds.

Effects of Reduction of Percent of Template (HMI) and Time of Static Synthesis on the Structure of MCM-22 Zeolite

2014 ◽  
Vol 805 ◽  
pp. 291-297
Author(s):  
Everton R.F. dos Santos ◽  
Romulo C.N. Leite ◽  
Aécio B. Sousa ◽  
Herve M. Laborde ◽  
Meiry Glaucia F. Rodrigues
Keyword(s):  
Adsorption Isotherms ◽  
Type I ◽  
X Ray Diffraction ◽  
X Ray ◽  
P 75 ◽  
Bet Method ◽  
Ft Ir ◽  
Static Conditions ◽  
Laminated Material ◽  
Scanning Electron

This work aims to study the effects of reducing the level of template HMI (100, 75, 50, 25 and 0% HMI) and time (10, 9 and 8 days) of static synthesis in the structure of MCM-22 zeolite. The synthesis of the MCM-22 (P) precursors was carried out by using hexamethyleneimine (HMI) as organic template under static conditions. The MCM-22 zeolites (100, 75 e 50% HMI) was obtained by the calcination of precursors MCM-22 (P) in a muffle to remove the occluded organic of precursors. These materials were characterized by X-ray diffraction (XRD), spectroscopy of X-ray for energy dispersive (EDX), adsorption isotherms of N2(BET method), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The XRD's and EDX's of all samples have confirmed the static synthesis of MCM-22, whose precursor and zeolite materials showed all the characteristic peaks of the topology MWW. The Adsorption isotherms of N2are of type I, represented by microporous materials, whose hysteresis (type H3) are representative of solids with pores of different geometries. The FTIR's shown that the precursors showed the characteristic bands of a laminated material. From the SEM's, it was found the samples calcined MCM-22 are constituted by strip-shaped crystals agglomerated with a depression in the central region. In the sample MCM-22 (P) 75% HMI (8 days), showed no crystals uniform due to the presence of unreacted material in relation to crystalline phases.

Electrodeposition of Sn-Ni Alloy Coatings and their Characterization

2015 ◽  
Vol 830-831 ◽  
pp. 655-658 ◽  
Author(s):  
Sandhya Shetty ◽  
Ampar Chitharanjan Hegde
Keyword(s):  
Sem Analysis ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Corrosion Resistant ◽  
X Ray ◽  
Ni Alloy ◽  
Corrosion Behaviors ◽  
Current Densities ◽  
Alkaline Bath ◽  
Scanning Electron

A new alkaline bath has been proposed for deposition of bright Sn-Ni alloy coatings on mild steel (MS). Depositions were carried out at different current densities (c.d.) and their corrosion behaviors were studied in 5 % NaCl solution by electrochemical AC and DC methods. Sn-Ni coating, deposited at low c.d. i.e. at 1.0 A/dm2 was found to be the most corrosion resistant compared to those at other higher c.d., even up to 4.0 A/dm2. This least corrosion rate (CR) is attributed to high wt. % Sn in the deposit. Increase of CR at high c.d. range is due to decrease of wt. % Sn, explained by the observed anomalous type of codeposition, followed by the bath. Regardless of the deposition c.d., the bath developed bright coatings, inherent of Sn-Ni alloy. Experimental results are discussed taking in account of the phase structure, composition and surface morphology of the coatings, evidenced by X-ray diffraction (XRD), Energy Dispersive X-ray (EDX) and Scanning Electron Microscopy (SEM) analysis.

scholarly journals Facile Synthesis of Micro CuO Crystals for Li Ion Full Battery

2021 ◽  
Author(s):  
Y.Z. Song ◽  
Z.J. Liu ◽  
B.X. Qi ◽  
Mengting Li ◽  
Jimin Xie ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Graphite Anode ◽  
Facile Synthesis ◽  
X Ray ◽  
Infrared Spectrometer ◽  
One Step ◽  
Current Densities ◽  
Li Ion ◽  
Charge Discharge ◽  
Scanning Electron

Abstract One step facile synthesis of micro CuO crystals is carried out by hydrothermal method. The porous lithium foil/Li-graphite is used as the anode for CuO-Li ion full battery. The micro CuO crystals are characterized by scanning electron micro porousscopy, X-ray powder diffractometer, Fourier Transform infrared spectrometer, thermogravimeter and differential scanning calorimeter. The battery with porous lithium foil/graphite anode is tested by the galvanostatic current charge-discharge technology at higher current densities of 0.25～0.5 mA/cm2. The porous lithium foil-graphite anode can effectively improve the discharge capacity of the CuO crystal battery.

Microstructural effect on corrosion of tungsten in SF6 environment

1995 ◽  
Vol 10 (1) ◽  
pp. 8-12
Author(s):  
W. Wong-Ng ◽  
C. S. Choi ◽  
L. P. Cook
Keyword(s):  
Electron Microscopy ◽  
Preferred Orientation ◽  
Corrosion Process ◽  
Type I ◽  
Type Ii ◽  
Drawing Process ◽  
X Ray ◽  
Deep Pits ◽  
Microstructural Effect ◽  
Scanning Electron

Reaction of tungsten (W) with SF6 has been studied using two types of samples. The first type (type I) consisted of rods fabricated by a drawing process and the second type (type II) consisted of square plates cut from a hot pressed billet. After the corrosion experiments, scanning electron microscopy (SEM) examination of the type I sample indicated the presence of deep pits parallel to the rod axis. X-ray analysis of these rods showed preferred orientation. Pole figure measurement was subsequently conducted to quantify the preferred orientation by using neutron diffraction. A significant orientation effect on the corrosion process was found, possibly originating from the considerable granular elongation parallel with the rod axis produced during the fabrication process. In contrast, the type II sample showed no directional corrosion and insignificant preferred orientation.

scholarly journals Demonstration of the Formation of Porous Silicon Films with Superior Properties Formed on Polished (100) Si with Screen-Printed Back Contacts

2007 ◽  
Vol 31 ◽  
pp. 249-253 ◽  
Author(s):  
Priyanka Singh ◽  
Shailesh N. Sharma ◽  
G. Bhagavannarayana ◽  
M. Husain ◽  
M. Lal
Keyword(s):  
Porous Silicon ◽  
Gravimetric Analysis ◽  
Back Contact ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
X Ray ◽  
Anodization Time ◽  
Current Densities ◽  
Scanning Electron ◽  
Screen Printed

Porous silicon (PS) layers were formed by anodization on polished substrates of (1 0 0) Si at different current densities for a fixed anodization time of 30 mins. using different screenprinted/ evaporated back contacts (Ag, Al) respectively. The PS films has been characterized by high resolution X-ray diffraction (HRXRD), photoluminescence (PL), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) techniques respectively. Porosity and thickness of PS layers were estimated by gravimetric analysis. The properties of PS formed using screen-printed Ag & Al as the back contacts (SP-(Ag/Al)) was found to be superior as compared to the corresponding films with evaporated back contacts (EV-(Ag/Al)). The PS formed with screenprinted Ag & Al-back contacts shows better crystalline perfection, higher stability, higher PL efficiency and negligible PL decay compared to that formed with evaporated Ag & Al- as the back contact for the same current density and time of anodization.

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