Quantitative Study on the Metal Dissolution Reaction with Multivalent Cations by a Modified Secm Mode: Pure Ti as a Case

Abstract

Metal corrosion exhibits coupled multi-reaction features, making it challenging to quantitatively study the dissolution reaction with variable-valent cations, particularly in valence quantification. This work develops a novel scanning electrochemical microscopy mode and applies it to Ti dissolution study in acidic fluorides. This mode identifies the potential-dependent corrosion reactions and quantifies the valence evolution of Ti from HER to transpassive regions. Results provide direct electrochemical evidence for soluble Ti(z≤3), for the first time, and revise the reported dissolution equation. The proposed mode overcomes the drawbacks of macro-electrochemical analysis based on coupling informationand provides an effective quantitation method for anodic reactions.

Keywords: A. Titanium, A. Acid solutions, B. polarization, C. Anodic dissolution, C. Passivity, C. Transpassivity