Home | My Profile | Contact Us
Research Trends Products  |   order gateway  |   author gateway  |   editor gateway  
Register | Forgot Password

Author Resources
 Author Gateway
 Article submission guidelines

Editor Resources
 Editor/Referee Gateway

 Regional Subscription Agents/Distributors
Current Topics in Electrochemistry   Volumes    Volume 6 
A review on the corrosion and corrosion inhibition of cadmium in aqueous solutions
W. A. Badawy, F. M. Al-Kharafi
Pages: 33 - 73
Number of pages: 41
Current Topics in Electrochemistry
Volume 6 

Copyright © 1998 Research Trends. All rights reserved

Cadmium is occuring at the dividing line between noble and base metals. The metal has better corrosion resistance than zinc and a greater domain for immunity. The remarkable biological and environmental pollution caused by cadmium makes the corrosion behaviour of this metal important case worthy of intensive studies. The few investigations done on cadmium in the last decades were concerned with the mechanism of anodic dissolution of Cd and cathodic reduction of Cd2+ in aqueous solutions. The proposed mechanism involves two consecutive charge transfer reactions. In the present investigation a systematic study of the electrochemical behaviour of Cd in aqueous solutions of different pH was carried out. The effect of chloride ions on the corrosion behaviour of the metal was investigated. The inhibition of the corrosion process taking place at the metal solution interface using different alcohols was studied. Open-circui potential measurements, polarization and electrochemical impedance spectroscopy (EIS) techniques were employed. The experimental results have shown that the corrosion behaviour of the metal in aqueous solutions is dependent on the solution pH. The presence of oxygen passivates the metal surface in neutral and basic solutions. In acidic solutions, no remarkable effect of oxygen was recorded. EIS data showed the presence of two phase maxima in neutral solutions which indicates the presence of two consecutive processes with two different time constants. The mechanism of the corrosion and passivation processes occurring at the electrode/electrolyte interface in different solutions was discussed. From the investigated alcohols, n-propanol was found to be the most efficient inhibitor of cadmium corrosion in aqueous solutions. The corrosion inhibition process was based on the adsorption of the alcohol molecules on the metal surface. The corrosion inhibition efficiency increases as the chain length of the alkyl radical increases. The adsorption of alcohol molecules was found to obey the Freundlich isotherm, θ = K Cn. A concentration of ≥ 0.075 mole fraction of n-propanol in the aqueous solution of pH13 has led to a corrosion inhibition efficiency of more than 97%. The mechanism of corrosion inhibition process was discussed. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) confirm the proposed mechanism.
Buy this Article


Buy this article
Buy this volume
Subscribe to this title
Shopping Cart

Quick Links
Search Products
Browse in Alphabetical Order : Journals
Browse by Subject Classification : Journals

Ordering Information Ordering Information
Downloadable forms Downloadable Forms