Abstract
The efficiency of Thymus vulgarise extract (TVE) as a nontoxic corrosion inhibitor for copper and α-brass in 1 M HNO3 has been tested by weight loss and electrochemical techniques such as potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The calculated adsorption thermodynamic parameters indicated that the adsorption was a spontaneous, exothermic process accompanied by a decrease in entropy. The inhibition efficiency increases with increasing the concentration of the extract in HNO3 solution and decreases with increasing the temperature. The adsorption of the extract on the copper and α-brass surfaces in the acid solution was found to obey Langmuir's adsorption isotherm. Scanning electron microscope (SEM) results showed the formation of a protective film on the copper and α-brass surfaces in the presence of TVE. The results obtained from different techniques were in good agreement.
| Original language | English |
|---|---|
| Pages (from-to) | 5126-5154 |
| Number of pages | 29 |
| Journal | International Journal of Electrochemical Science |
| Volume | 9 |
| Issue number | 9 |
| State | Published - Sep 2014 |
| Externally published | Yes |
Keywords
- Copper
- Corrosion inhibition
- EDX
- EFM
- EIS
- SEM
- Thymus vulgarise
- α-brass