Non-Classical Crystal Growth Recipe using nanocrystalline ceria a detailed review

Abstract

In this review, room temperature (RT) precipitation of the nanocrystalline-ceria (nc-ceria) re-dispersed and subsequently size-reduced by 20 kHz probe sonication in 25 % ethylene glycol/ 75 % DI-water mixed media is investigated. The sonication result in three nanostructured products: (1) water-soluble supernatant nc-ceria (Ce_Sl@RT), (2) settled gelatinous nc-ceria mass (Ce_SS@RT), and (3) ambient dried nc-ceria solid powder (Ce_SP@RT) product along with the parent RT nc-ceria (Ce@RT) precipitates. Surface/interface attributes are investigated systematically with the help of suitable spectroscopic probes. By following this synthesis protocol, the nc-ceria is made to cohabit with a variety (water, ethylene glycol, air) of neighbors that lead to the distinct surface and interface termination. The physical and chemical aspects of these varieties of the specialized surface terminated nc-ceria are explored coherently with respect to the Ce@RT precipitate. The second aspect of this review is devoted to the biomineralization for which the sonication derived Ce_Sl@RT is the candidate of choice. Aging of Ce_Sl@RT is physically tracked to mimic the natural aquatic medium crystal growth by the biomineralization process. In-situ TEM is extensively used to demonstrate the non-classical crystal growth mechanism physically. Uniquely TEM electron beam (e-beam) is exploited to aid both in the material manipulation and probing.