Comparison of Electrochemical Properties of Ni+MoS2 and Ni Coatings in an Alkaline Solution

2015 ◽  
Vol 228 ◽  
pp. 225-230
Author(s):  
Magdalena Popczyk ◽  
Bożena Łosiewicz

The Ni+MoS2composite coatings were obtained by electrolytic co-deposition of crystalline nickel with molybdenum sulfide powder from an electrolyte containing suspension of this powder. For comparison, the Ni coating was also deposited. These coatings were obtained in galvanostatic conditions at the current density ofjdep= -250 mA cm-2. A scanning electron microscope was used for surface morphology characterization of the coatings. The behavior of the coatings was investigated in the process of hydrogen evolution reaction from 5 M KOH solution using steady-state polarization and electrochemical impedance spectroscopy methods. It was found that introduction of molybdenum sulfide into nickel matrix, evokes developed and rough surface which is the reason for the increase in the rate of the HER as comapred to the smooth Ni electrode. Thus obtained coatings may be useful in application as electrode materials for the HER.

2015 ◽  
Vol 228 ◽  
pp. 299-304
Author(s):  
Magdalena Popczyk ◽  
B. Łosiewicz ◽  
Eugeniusz Łągiewka ◽  
A. Budniok

The Ni-P, Ni-Co-P and Ni-P+Co coatings were obtained in galvanostatic conditions at the current density ofjdep= -200 mA cm-2. A stereoscopic microscope was used for surface morphology characterization of the coatings. The X-ray diffraction (XRD) method was used to determine phase composition of the coatings and the atomic absorption spectrometry (AAS) was applied to specify their chemical composition. The behavior of the obtained coatings was investigated in the process of hydrogen evolution reaction (HER) from 5 M KOH using steady-state polarization and electrochemical impedance spectroscopy (EIS) methods. It was found that introduction into Ni-P amorphous matrix powder of cobalt produced porous electrode materials which could be used for the HER.


2006 ◽  
Vol 514-516 ◽  
pp. 1182-1185 ◽  
Author(s):  
Magdalena Popczyk ◽  
Julian Kubisztal ◽  
Antoni Budniok

Ni+Mo+Si coatings were obtained by electrolytic codeposition of crystalline nickel with molybdenum and silicon powders from an electrolyte containing suspension of these powders. These coatings were obtained in galvanostatic conditions, at the current density of -0.100 A cm-2. Thermal treatment of these coatings in argon atmosphere was done at temperature of 1100oC for 1 hour. A scanning electron microscope was used for surface morphology characterization of the coatings. Chemical composition of obtained coatings was determined by Xray fluorescence spectroscopy method and phase composition investigations were conducted by Xray diffraction method. It was found that introduction of molybdenum and silicon into nickel matrix, causes of obtained coatings about very rough surface. Thermal treatment of these coatings influenced their surface. The surface after thermal treatment is more compact and less rough than the as-deposited one.


2006 ◽  
Vol 514-516 ◽  
pp. 460-464 ◽  
Author(s):  
Magdalena Popczyk ◽  
Antoni Budniok ◽  
Henryk Scholl ◽  
Tadeusz Blaszczyk

Ni-P, Ni-Co-P and Ni-W-P layers were obtained in galvanostatic conditions, at the current density jdep= 0.200 A cm-2. The X-ray diffraction method was used to determine phase composition of the layers and the atomic absorption spectrometry was applied to specify their chemical composition. A metallographic, stereoscopic and tunneling microscope and also Form Talysurf-type profilograph were used for cross-section and surface morphology characterization of the layers. The behaviour of obtained layers was investigated in the processes of hydrogen and oxygen evolution from 5 M KOH using voltammetry method. It was ascertained that, introduction of cobalt or tungsten into Ni-P matrix, lead to obtain the layers about very developed surface. Thus obtained layers may be useful in application as electrode materials in electrochemistry.


2015 ◽  
Vol 228 ◽  
pp. 273-276
Author(s):  
Magdalena Popczyk ◽  
Bożena Łosiewicz

The Ni+MoO2and Ni+Cr2O3composite coatings were prepared by the electrodeposition under the galvanostatic conditions (jdep= -200 mA cm-2) from the nickel bath containing powder of MoO2or Cr2O3. Studies of hydrogen evolution reaction (HER) in 5 M KOH solution at room temperature were conducted using steady-state polarization and electrochemical impedance spectroscopy (EIS) methods. It was ascertained that the HER rate is higher for the Ni+MoO2composite electrode in comparison with the Ni+Cr2O3composite electrode due to the presence of Mo in the nickel matrix.


2015 ◽  
Vol 228 ◽  
pp. 219-224
Author(s):  
Magdalena Popczyk ◽  
Julian Kubisztal ◽  
Bożena Łosiewicz ◽  
A. Budniok

The Ni+Cr+Si, Ni+Mo+Si and Ni+W+Si composite coatings were obtained by electrodeposition of crystalline nickel from an electrolyte containing suspension of suitable metallic and non-metallic components (Cr, Mo, W and Si). These coatings were obtained galvanostatically at the current density of jdep = -0.100 A cm-2 and at the temperature of 338 K. Chemical composition of the coatings was determined by energy dispersive spectroscopy (EDS). The electrochemical activity of these electrocatalysts was studied in the process of hydrogen evolution reaction (HER) in 5 M KOH solution using steady-state polarization and electrochemical impedance spectroscopy (EIS) methods. The kinetic parameters of the HER on particular electrode materials were determined. It was found that Ni+Mo+Si composite coatings are characterized by enhanced electrochemical activity towards the HER as compared with Ni+W+Si and Ni+Cr+Si coatings due to the presence of Mo and increase in electrochemically active surface area.


Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.


Author(s):  
E. Hendarto ◽  
S.L. Toh ◽  
J. Sudijono ◽  
P.K. Tan ◽  
H. Tan ◽  
...  

Abstract The scanning electron microscope (SEM) based nanoprobing technique has established itself as an indispensable failure analysis (FA) technique as technology nodes continue to shrink according to Moore's Law. Although it has its share of disadvantages, SEM-based nanoprobing is often preferred because of its advantages over other FA techniques such as focused ion beam in fault isolation. This paper presents the effectiveness of the nanoprobing technique in isolating nanoscale defects in three different cases in sub-100 nm devices: soft-fail defect caused by asymmetrical nickel silicide (NiSi) formation, hard-fail defect caused by abnormal NiSi formation leading to contact-poly short, and isolation of resistive contact in a large electrical test structure. Results suggest that the SEM based nanoprobing technique is particularly useful in identifying causes of soft-fails and plays a very important role in investigating the cause of hard-fails and improving device yield.


2011 ◽  
Vol 415-417 ◽  
pp. 642-647
Author(s):  
En Zhong Li ◽  
Da Xiang Yang ◽  
Wei Ling Guo ◽  
Hai Dou Wang ◽  
Bin Shi Xu

Ultrafine fibers were electrospun from polyacrylonitrile (PAN)/N,N-dimethyl formamide (DMF) solution as a precursor of carbon nanofibers. The effects of solution concentration, applied voltage and flow rate on preparation and morphologies of electrospun PAN fibers were investigated. Morphologies of the green fibers, stabilized fibers and carbonized fibers were compared by scanning electron microscope (SEM). The diameter of PAN nanofibers is about 450nm and the distribution of diameter is well-proportioned. Characterization of the elements changes of fibers were performed by X-ray photoelectron spectroscopy (XPS).


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