Electrochemical behavior of iron electrode in sodium sulphide solutions

I. Zaafarany

Department of Chemistry, Faculty of Applied Science, Umm Al-Qura University, Makkah Al-Mukaramah (Saudi Arabia).

Received on August 08, 2009 and accepted on October 15, 2009

ABSTRACT

The electrochemical behavior of iron electrode in sodium sulphide solutions was studied using cyclic voltammograms technique. The morphology of the surface before and after immersion of iron electrode in Na2S solution was also studied using scanning electron microscope (SEM) and energy dispersive analysis of X-rays (EDAX). Two anodic peaks were observed in the anodic scan due to the formation of FeS2, converted to FeS on the surface of electrodes. On the other hand one cathodic peak occurred due to the reduction of FeS2 in the cathodic branch of cyclic voltammograms. The formation of iron sulphide was supported by SEM photograph and increase of sulphur counts observed in EDAX analysis. The current for peaks (A and B) increases with increasing sodium sulphide concentration and voltage scan rate but the values of peak potential remains unchanged.

Keywords : Iron, sodium sulphide, cyclic voltammogram, SEM, EDAX.