Atomically-precise colloidal nanoparticles of cerium dioxide

Abstract

Synthesis of truly monodisperse nanoparticles and their structural characterization to atomic precision are important challenges in nanoscience. Success has recently been achieved for metal nanoparticles, particularly Au, with diameters up to 3 nm, the size regime referred to as nanoclusters. In contrast, families of atomically precise metal oxide nanoparticles are currently lacking, but would have a major impact since metal oxides are of widespread importance for their magnetic, catalytic and other properties. One such material is colloidal CeO2 (ceria), whose applications include catalysis, new energy technologies, photochemistry, and medicine, among others. Here we report a family of atomically precise ceria nanoclusters with ultra-small dimensions up to ~1.6 nm (~100 core atoms). X-ray crystallography confirms they have the fluorite structure of bulk CeO2, and identifies surface features, H+ binding sites, Ce3+ locations, and O vacancies on (100) facets. Monodisperse ceria nanoclusters now permit investigation of their properties as a function of exact size, surface morphology, and Ce3+:Ce4+ composition.

CeIV70Oxosulfate Rings, Frameworks, Supramolecular Assembly, and Redox Activity**

“…Owed to facile Ce III ‐Ce IV redox behavior and concomitant oxygen transport, ceria nanoparticles are used as automotive redox catalysts, in oxide fuel cells, and as photoactive solar cell materials [15] . Atomically precise cerium‐oxo clusters are valuable to understand form‐function relationships; and Ce 10 , Ce 20 , Ce 22 , Ce 24 , Ce 38 and Ce 40 have been isolated, some of which have distinct Ce III and Ce IV sites [6e, 12] . Farha and co‐workers recently demonstrated catalytic activity of Ce 38 , owed to the high porosity and redox activity of the solid material [16] …”

Modeling the Kinetic Behavior of Reactive Oxygen Species with Cerium Dioxide Nanoparticles

“…Mitchell, Abboud and Christou explore the opposite end of the ceria size spectrum with an upper limit of ~ 1.8 nm and detail the H + and other various ligand binding sites as a function of ceria surface Miller Index, as well as the location of Ce 3+ and oxygen vacancies [24].…”

Untitled

“…The LLOD and LLO quantitation (LLOQ) are the concentrations that give signal-to-noise ratio of 3:1 or 10:1, respectively, which can be detected and verified by the relation of standard deviation of response (SD) to the slope of calibration curves (S): [37] LLOD=3.3 SD/S, LLOQ=10 SD/S All peaks were well resolved and the precision was acceptable. System suitability of the method was studied through method development by calculating LOD, LOQ, intercept, slope, retention time, standard error, standard error estimate, and repeatability favorable for the system are summarized in Tables 1-3.…”