The Utilization of Scanning Electrochemical Microscopic (SECM) Technique in Corrosion Monitoring

Various conventional electrochemical corrosion measurements have been deployed to evaluate the corrosion phenomenon on various metallic materials. However, these techniques have been inadequate to elucidate the corrosion process on the metal/solution interface at the micrometer scale with early interpretation. Hence, we are in need to discover the appropriate technique with a longitudinal determination in the microscopic level that might specify the early steps of surface degradation in the actual phase. Recently, several methods, including scanning reference electrode (SRET) techniques, scanning vibrating electrode (SVET), localized electrochemical impedance spectroscopy (LEIS), and scanning electrochemical microscopy (SECM) have been established to overcome the issues with conventional electrochemical techniques. Amongst the methods, SECM has been presented to assess the corrosion phenomenon in early stages at the micrometer scale, as it delivers the electrochemical behavior and surface topographic evidence about the electrochemical reactions at the interface in solution. Owing to their higher spatial resolution and electrochemical sensitivity, the application of SECM has enabled inspection on the metal/electrolyte interface. This method has previously delivered exact exciting evidence regarding the beginning of localized corrosion of numerous metallic materials, the formation of anodized layers on metallic samples, and the illustration of thin inhibitor films on various metallic materials and galvanic corrosion of Zn–Fe cell. Moreover, the usage of SECM to investigate the degradation of protective coatings on various metallic substrates is very promising in investigating the multifaceted reactions happening in the aggressive environment. This chapter intends to demonstrate the fundamentals, different modes briefly, and the feasibility of utilizing the SECM technique in corrosion monitoring research.