Open AccessAn unexpected phase transformation of ceria nanoparticles in aqueous media
Author(s) -
Satyanarayana V N T Kuchibhatla,
Ajay Karakoti,
Andreas E. Vasdekis,
Charles F. Windisch,
Sudipta Seal,
Suntharampillai Thevuthasan,
Donald R. Baer
Publication year - 2019
Publication title -
journal of materials research/pratt's guide to venture capital sources
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.788
H-Index - 148
eISSN - 0884-2914
pISSN - 0884-1616
DOI - 10.1557/jmr.2018.490
Subject(s) - materials science , nanoparticle , transformation (genetics) , phase (matter) , aqueous medium , aqueous solution , chemical engineering , nanotechnology , chemistry , organic chemistry , biochemistry , engineering , gene
Cerium oxide Nanoparticles (CNPs) are of significant interest to the scientific community due to their wide spread applications in a variety of fields. It is proposed that size dependent variations in the extent of Ce3+ and Ce4+ oxidation states of cerium in CNPs determines the performance of CNPs in application environments. To obtain greater molecular and structural understanding of chemical state transformations previously reported for ceria ≈ 3 nm nanoparticles (CNPs) in response to changing ambient conditions, microXRD and Raman measurements were carried out for various solution conditions. The particles were observed to undergo a reversible transformation from a defective ceria structure to a non-ceria amorphous oxy-hydroxide/peroxide phase in response to the addition of 30% hydrogen peroxide. For CNPs made up of ~8 nm crystallites, a partial transformation was observed and no transformation was observed for CNPs made up of ~ 40 nm crystallites. This observation of differences in size dependent transition behavior may help explain the benefits of using smaller CNPs in applications requiring regenerative behavior.