17 O 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 17 O enrichment allows detection of oxygen ions in the "bulk" part of nanoparticles, selective NMR observation of surface oxygen species can be realized using 17 O-labeled water to enrich surface oxygen sites at a relatively low temperature. The high-frequency 17 O 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.
Bibliographical noteFunding Information:
This work was supported by the National Natural Science Foundation of China (NSFC) (91745202, 21573103, and 21825301) and the NSFCRoyal Society Joint Program (21661130149 and 21611130177). The ECUST group also thanks the Programme of Introducing Talents of Discipline to Universities (B16017) and the National Super Computing Centre in Jinan for computing time. L.P. thanks the Royal Society and Newton Fund for Royal Society-Newton Advanced Fellowship. This work was also supported by a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.