A review on bipolar electrochemistry for corrosion testing: highlighting mechanisms, applications, and future prospects

Abstract

Bipolar electrode corrosion (BPEC), utilizing bipolar electrochemistry, has emerged as a pivotal technique in corrosion research by leveraging potential gradients between two feeder electrodes immersed in electrolyte solutions. This review provides a comprehensive exploration of the methodology, applications, and underlying corrosion mechanisms associated with BPEC, emphasizing its versatility across diverse domains. By establishing an electric field gradient, BPEC facilitates simultaneous oxidation and reduction reactions across a wide electrochemical potential range, typically inducing oxidation near to the negative feeder electrode and reduction adjacent to the positive electrode. The straightforward setup allows efficient screening of corrosion behavior under varied conditions, offering insights into anodic-to-cathodic corrosion dynamics on individual electrodes. Application of BPEC to steel samples reveals insights into pitting, crevice corrosion, general corrosion, and passive behavior, enabling thorough assessment of corrosion phenomena. Integration with sample arrays accelerates comparative studies, while analysis of local current and potential distributions enhances methodological understanding. This review underscores BPEC’s capability for spectroscopic, quantitative, and qualitative assessment of multiple samples in galvanic corrosion studies, providing a streamlined approach to evaluate comparative corrosion behavior within a single experiment. Moreover, evaluating pitting morphology on anodic surfaces offers a straightforward method for quantifying and qualitatively assessing overall corrosion performance across diverse sample sets.