17O Solid-State NMR Studies of ZrO2 Nanoparticles

17O solid-state NMR spectroscopy was applied to study the structure of monoclinic and tetragonal zirconia nanoparticles with the help of density functional theory calculations for spectral assignments. Although high-temperature 17O enrichment allows detection of oxygen ions in the “bulk” part of nanoparticles, selective NMR observation of surface oxygen species can be realized using 17O-labeled water to enrich surface oxygen sites at a relatively low temperature. The high-frequency 17O NMR resonances arising from low-coordinated oxygen ions on the surface of monoclinic and tetragonal zirconia nanoparticles were observed for the first time. The results are the basis for further understanding of structure–properties relations of zirconia nanomaterials.