Great Influence of Anions for Controllable Synthesis of CeO₂ Nanostructures: From Nanorods to Nanocubes

Abstract

Controllable synthesis of well-shaped nanocrystals is of significant importance for understanding the surfacerelated properties as well as for the exploration of potential applications. Herein, CeO 2 nanorods and nanocubes were selectively synthesized using cerium(III) chloride and cerium(III) nitrate as precursor, respectively. Counter anions of the cerium source were crucial to the shapes of the resulting products. Intriguingly, the as-synthesized nanorods could be converted into nanocubes by the addition of an appropriate amount of NO 3ions into the hydrothermal reaction. The NO 3ions are considered as both a capping agent and an oxidizer during the formation of CeO 2 nanocubes. Moreover, the influences of several others anions are investigated. Br -, I -, and SO 4 2ions have similar roles to Clions, which lead to the formation of nanorods. The introduction of BrO 3ions can bring on the generation of irregular nanoparticles because they can function as an oxidizer but not a capping agent. The anion-induced controllable growth process is simple and low cost, which makes this strategy potentially useful for the preparation of other faceted nanostructures.

The influence of nano-architectured CeO supports in RhPd/CeO2 for the catalytic ethanol steam reforming reaction

“…Two types of shape-controlled nanoceria supports (nanocubes and nanorods) were prepared according to previously reported methodologies [18,[29][30][31]. For ceria nanocubes (CeO 2 -C) a NaOH solution (57.60 g NaOH dissolved in 210 mL of distilled water) was added dropwise into a Ce(NO 3 ) 3 ·6H 2 O solution (5.21 g of Ce(NO 3 ) 3 ·6H 2 O in 30 mL of distilled water) under vigorous stirring.…”

Effect of Alkali Metal Hydroxides on the Morphological Development and Optical Properties of Ceria Nanocubes Under Hydrothermal Conditions

“…17 Eventually, CeO 2 rods were converted into well-defined CeO 2 polyhedron particles with {200} and {111} facets. The growth rate of {200} appeared to be higher than that of {111}.…”

“…The effect of pH on the crystallization of nanosized CeO 2 was studied by Li W-H et al 16 It was claimed that the crystallites synthesized in an acidic hydrothermal medium are larger and more monodisperse than the ones produced in a neutral or alkaline medium. The effect of the counteranions of cerium source on CeO 2 nanostructures was investigated by Hu et al 17 They reported that the synthesized nanorods converted into cubes by addition of NO agent and an oxidizer during the formation of the CeO 2 cubes. The influence of several other anions (such as Br − , I − , and SO 2− 4 ) was also investigated showing that the basicity of the hydrothermal medium had a direct influence on the size and shape of the particles formed.…”

Influence of the Incorporation of CeO2 Nanoparticles on the Ion Exchange Behavior of Dodecylsulfate Doped Polypyrrole Films: Ac-Electrogravimetry Investigations

“…Numerous CeO 2 synthesis procedures have been reported in literature [10][11][12][13] leading to various nanoparticle morphologies. These materials were extensively studied owing to their many distinctive characteristics and applications such as catalysts in the fuel cell technology [14], gas sensor [15], catalytic wet oxidation [16][17], oxygen storage and release [18], wastewater treatment [19] or photo-catalytic oxidation of water [20].…”