The Hydration Structure at Yttria-Stabilized Cubic Zirconia (110)-Water Interface with Sub-Ångström Resolution

Abstract

The interfacial hydration structure of yttria-stabilized cubic zirconia (110) surface in contact with water was determined with ~0.5 Å resolution by high-resolution X-ray reflectivity measurement. The terminal layer shows a reduced electron density compared to the following substrate lattice layers, which indicates there are additional defects generated by metal depletion as well as intrinsic oxygen vacancies, both of which are apparently filled by water species. Above this top surface layer, two additional adsorbed layers are observed forming a characteristic interfacial hydration structure. The first adsorbed layer shows abnormally high density as pure water and likely includes metal species, whereas the second layer consists of pure water. The observed interfacial hydration structure seems responsible for local equilibration of the defective surface in water and eventually regulating the long-term degradation processes. The multitude of water interactions with the zirconia surface results in the complex but highly ordered interfacial structure constituting the reaction front.

A novel coating layer on zirconia using modified zinc phosphatizing method

“…The hydration structure at yttria stabilized zirconia and water interface in hydrothermal condition with sub angstrom resolution confirmed that Y 3+ and ZrO nanoparticles could release from the bulk because of chemisorbed water to the Zr sites of the zirconia surface and the OH − groups initiate the stressed sites and precede the degradation of the substrate. Due to the degradation phenomenon, the metal ions could be provided from the surface to combine with zinc and phosphate to form zinc phosphate coating 28) , which is similar to the previously confirmed zinc phosphatizing mechanisms.…”

Multiple water layers on AnO2 {111}, {110}, and {100} surfaces (An = U, Pu): A computational study

“…Multiple water layers have not, to our knowledge, been studied computationally on actinide or lanthanide oxides, although there is some very recent work on yttriastabilised zirconia, 27,28 a system which is isostructural with the lanthanide and actinide oxides. This paucity is in stark contrast to water adsorption on other metal oxides such as Cassiterite (SnO2) and rutile (TiO2), which has been studied extensively.…”

Tailoring the protonic conductivity of porous yttria-stabilized zirconia thin films by surface modification

“…11 This behavior can be attributed mainly to the reduced amount of oxygen vacancies on TiO 2 surfaces compared to YSZ, which act as active sites for water adsorption. 69,70,74 Furthermore, DFT calculations suggest that on amorphous TiO 2 the adsorption of hydroxyl groups is even less favorable compared to anatase TiO 2 , 75 which is also supported by the lower protonic conductivity in the case of the amorphous coating, especially at higher temperatures. However, water condensation in the pores may also play a role in the higher protonic conductivity in the case of the YSZ thin film with the crystalline TiO 2 (note that the pore size is also reduced due to the coating).…”

“…However, also surface defects, such as oxygen vacancies, play a significant role in the formation of surface protons as water fills the oxygen vacancies and forms hydroxyl groups. [68][69][70] In Kroeger-Vink notation, their formation is given by the reaction: 15,35,71,72…”