RT info:eu-repo/semantics/article T1 Combined amperometric/potentiometric probes for improved chemical imaging of corroding surfaces using Scanning Electrochemical Microscopy A1 Souto, Ricardo Manuel A1 Filotás, Dániel A1 Fernández Pérez, Bibiana María A1 Izquierdo Pérez, Javier A1 Nagy, Lívia A1 Nagy, Géza K1 Scanning Electrochemical Microscopy (SECM) K1 Microelectrode probes K1 pH 28 gradients K1 Galvanic corrosion K1 Iron K1 Copper AB Chemical visualization of corrosion processes using scanning electrochemical microscopy (SECM) in combined amperometric/potentiometric operation has been achieved by developing novel multi-barrel probes as tips. A Pt-based amperometric disc probe is employed for the detection and characterization of reactive sites on a corroding system, whereas a Sb-based disc microelectrode is employed to visualize local solution pH changes. Quasi-simultaneous imaging of localized corrosion micro-cells on the surface and the associated pH variations in the electrolyte, resulting from both the electrolysis of dissolved metal ions from the local anodes and the consumption of an oxidizing agent at the local cathodes, can be obtained in the same solution without changing the probe. Galvanic corrosion of a model Cu-Fe pair in chloride-containing solution was visualized with high spatial resolution by recording either line scans or 2D-images using the novel Pt/Sb multi-barrel tip. YR 2016 FD 2016 LK http://riull.ull.es/xmlui/handle/915/18997 UL http://riull.ull.es/xmlui/handle/915/18997 LA en DS Repositorio institucional de la Universidad de La Laguna RD 24-nov-2024