Effect of Ethylene Diamine Tetra Acetic Acid (EDTA) on the Surface Reaction Behavior and the Hydrogen Evolution Efficiency of Ni-30at.%Cu Electrode in Alkaline Medium
DOI:
https://doi.org/10.3329/bjsir.v43i2.955Keywords:
Ni-30at.%Cu electrode, EDTA, Electrochemical transformation, Surface reactions, Hydrogen evolution, Hydrogen evolution reactions (HER)Abstract
The surface reaction characteristics, hydrogen evolution efficiency and hydrogen evolution reaction kinetics of Ni-30at.%Cu electrode have been investigated in 30wt.%KOH electrolyte in presence and absence of ethylene diamine tetra acetic acid (EDTA) at room temperature by cyclic voltammetric technique. Cyclic voltammogram of the electrode showed three couples of oxidation-reduction peaks in between the potential range - 1.1 to + 0.4 V. The peak couples were originated from the electrochemical transformations of Ni(0) ←→ Ni(OH)2, Cu(0) ←→ Cu(I) and Cu(I) ←→ Cu(OH)2. An interference of the adsorped hydrogen over Cu(0) surface on the transformation of Ni(OH) 2 → Ni(0) was found. It was realized that added EDTA forms Cu-EDTA complex over the electrode surface. With increasing the amount of EDTA, the thickness of Cu(OH) 2 layer gradually decreased. Addition of 0.04g, 0.08g and 0.12g EDTAincreased the hydrogen evolution efficiency of the electrode more than 6%, 12% and 17%. Tafel plots for both the systems showed two well-defined Tafel regions. 0.12g EDTA increased the exchange current density (i0) values 1.3 times for both the Tafel regions. The observed i0 value for the high overpotential (η) region is 1.8 and 2.9 times higher than those of Ni and Cu electrodes. The Tafel slope (b) values for both the low and high η regions are smaller than those observed for without EDTA system and also for the Ni electrode. From the achieved information, it can be concluded that addition of EDTA remarkably increased the hydrogen evolution efficiency of the Ni-30at.%Cu electrode. It seems that hydrogen evolution reactions (HER) followed like mechanisms in absence and presence of EDTA.
Key words: Ni-30at.%Cu electrode, EDTA, Electrochemical transformation, Surface reactions, Hydrogen evolution, Hydrogen evolution reactions (HER)
DOI: 10.3329/bjsir.v43i2.955
Bangladesh J. Sci. Ind. Res. 43(2), 145-158, 2008
Downloads
140
82
Downloads
How to Cite
Issue
Section
License
Bangladesh Council of Scientific and Industrial Research (BCSIR) holds the copyright to all contents published in Bangladesh Journal of Scientific and Industrial Research (BJSIR). A copyright transfer form should be signed by the author(s) and be returned to BJSIR.
The entire contents of the BJSIR are protected under Bangladesh Council of Scientific and Industrial Research (BCSIR) copyrights.
BJSIR is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial License (CC BY-NC) Creative Commons Attribution-NonCommercial 4.0 International License which allows others remix, tweak, and build upon the articles non-commercially, and although their new works must also acknowledge and be non-commercial, they dont have to license their derivative works on the same terms.
