Electrochemical Study of Zinc Adsorption on Yttria-Stabilized Zirconia-Water Interfaces

Abstract

Research has shown that zinc ions can mitigate the corrosion of the alloy materials in nuclear power plants in addition to reducing radiation contaminations. Understanding how zinc ions alter the interfacial structure of the alloy surface is therefore important in improving the life cycle of the materials and achieving higher burnups of the nuclear fuels. While the corrosion mitigation of zinc on nickel and stainless-steel alloys has been widely studied and reported, its effect on zirconium oxide surfaces, i.e. the oxide layer of zirconium alloys exposed to the aqueous solution, has rarely been reported. Meanwhile, zirconium oxide also serves as the solid oxide fuel cell electrolyte in energy storage. The study of the corrosion mitigation mechanism on zirconia could also contribute to the successful commercialization of SOFC technologies as cleaner and more efficient energy conversion electrochemical systems. In this work, we utilize the electrochemical techniques to study the interfacial structure changes under the influence of zinc ions on the yttria-stabilized zirconia (YSZ) surfaces on the (100), (110), and (111) orientations in contact with aqueous solution with and without externally applied electric potentials. The experimental measurements indicated the modification of the interfacial structures by zinc on (100) and (111) surfaces is strongly influenced by the applied external electric fields, while the modification of surface structure by zinc ions is not as evident on the (110) surface. Our study also showed that the Zn2+ adsorption layers on the oxide surfaces could be better preserved by tuning the electric potential on the oxide substrates towards the negative potentials.