Comparative Electrochemical study of niobium, molybdenum, cobalt chromium alloy and gold electrodes in milk and tap water

Attia, Enas Mohamed; Abou Koffa, Fatma Mokhtar; Abou Shahba, Rabab Mohamed

doi:10.21608/ijtar.2024.168826.1011

Comparative Electrochemical study of niobium, molybdenum, cobalt chromium alloy and gold electrodes in milk and tap water

Document Type : Original Article

Authors

¹ Chemistry Department, Faculty of Science (Girls), Al-Azhar University, Nasr City, Cairo, Egypt

² Additives and Miscellaneous Department at Central Public Health Laboratories - Ministry of Health

10.21608/ijtar.2024.168826.1011

Abstract

In both milk and water, the corrosion behavior of four distinct electrodes—niobium, molybdenum, cobalt chromium-alloy, and gold electrodes—was studied at temperatures ranging from 20 to 50°C. Analysis of tap water and milk were performed. Open circuit potential and potentiodynamic polarization experiments were used in the inquiry. The open circuit data show the four electrodes' declining steady potential values (E_ss) in the ensuing direction: CoCr- Alloy > Au > Mo > Nb. For water and milk, this sequence was followed regardless of temperature. But milk at 50°C modified the order to be: Au > CoCr- alloy > Mo > Nb. At all temperatures, the E_ss values in tap water were higher than those in milk solutions, indicating more passivation in tap water. All of the investigated electrodes show rising corrosion rate (C_R) values during potentiodynamic polarization experiments as the solution temperature rises. At all temperatures, milk had greater C_R values than tap water for the four electrodes. According to C_R values, the following is the order of passivity: Au > Mo > CoCr-alloy > Nb in milk, Au > Mo > Nb > CoCr- alloy in water. Calculations and discussions were made about the activation energy (E_a), enthalpy change (〖∆H〗^°), and entropy change (〖∆S〗^°) of corrosion.

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