Electrochemical Impedance Spectroscopy (EIS): A Review Study of Basic Aspects of the Corrosion Mechanism Applied to Steels

Abstract

AC impedance measurements have been applied for over twenty years in electrochemistry and physics to investigate the electrical properties of conductive materials and their interfaces using an external electrical impulse (VOLTAGE, V or CURRENT, I) as driving force. Furthermore, its application has recently appeared to be destined in the Biotechnology field as an effective tool for rapid microbiologic diagnosis of living organism in situ. However, there is no doubt that the electrochemical impedance spectroscopy (EIS) is still one of the most useful techniques around the world for metal corrosion control and its monitoring. Corrosion has long been recognized as one of the most expensive stumbling blocks that concern many industries and government agencies, because it is a steel destructive phenomenon that occurs due to the chemical interaction with aqueous environments and takes place at the interface between metal and electrolyte producing an electrical charge transfer or ion diffusion process. Consequently, it is experimentally possible to determine through the EIS technique the mechanism and control that kinectics of corrosion reactions encounter. First, EIS data is collected through a potentiostat/galvanostat apparatus. After, it is fitted to a mathematical model (i.e. an equivalent electrical circuit, EEC) for its interpretation and analysis, fundamentally seeking a meaningful physical interpretation. Finally, this review reports some basic aspects of the corrosion mechanism applied to steels through the experimental EIS response using Nyquist or Bode plots. Examples are given for different applied electrochemical impedance cases in which steel is under study intentionally exposed to a corrosive aqueous solution by applying a sinusoidal potential at various test conditions.

Intrinsic Lability of NiMoO4to Excel the Oxygen Evolution Reaction

“…The low phase angle for the NiO­(OH) ED also highlighted favorable OER kinetics with the NiO­(OH) ED catalyst. , In the Bode plot of NiO­(OH) ED /NF and Ni­(OH) 2 /NF, two changes in the slopes (Figure S18) are further correlated with the two time constants of the Nyquist plot (Figures e and S17). Moreover, the typical Nyquist and Bode plots for NiO­(OH) ED /NF inferred a favorable electron transfer between the in-situ-constructed oxyhydroxide electrode–electrolyte interfacial layer controlled by a spontaneous charge and mass transfer mechanism. , …”

Design of halloysite-based nanocomposites by electrospinning for water treatment

“…It allows determining the photo-induced charge separation efficiency and transmission rate. 81,82 The Nyquist curves showed that resistance decreased after adding TiO2 and upon exposure to visible light radiation (Fig. 5.a).…”

Identification of Corrosion Minerals Using Shortwave Infrared Hyperspectral Imaging

“…Several methods have been developed in the past to detect and/or quantify the presence of corrosion. Non-destructive techniques such as electrochemical impedance spectroscopy (EIS) [ 3 ], linear polarization resistance (LPR) [ 4 ], Ultrasonic measurement, Eddy current [ 5 ] and Electrical resistance (ER) [ 6 ] can measure the corrosion rate. These techniques are all single point measurements.…”