Formation of CeO₂ Nanotubes from Ce(OH)CO₃ Nanorods through Kirkendall Diffusion

Abstract

In this paper, CeO(2) nanotubes based on the Kirkendall effect (for simplicity, this type of nanotubes is denoted as K-type CeO(2) nanotubes) are fabricated through a solid-liquid interface reaction between Ce(OH)CO(3) nanorods and NaOH solutions. Our studies indicate the formation mechanism of K-type CeO(2) nanotubes is quite different from those of CeO(2) nanotubes subjected to template (T-type CeO(2) nanotubes) and lamellar rolling (L-type CeO(2) nanotubes) reported previously by our group. The K-type CeO(2) nanotubes are prepared by congregating Kirkendall voids and subsequent calcinations. The time evolution processes are imaged by TEM, and the results show that as the reaction processes, interior spaces are formed and enlarged in Ce(OH)CO(3) nanorods to form K-type CeO(2) nanotubes. In contrast, the interior space in T-type CeO(2) nanotubes decreases with reaction time. XRD is applied to study the phase transformation in the formation process of K-type CeO(2) nanotubes. Our study also indicates NaOH and reaction temperature are two key factors responsible for formation of K-type CeO(2) nanotubes. Combined with the T- and L-type nanotubes, three types of CeO(2) nanotubes with different formation mechanisms are successfully synthesized in one reaction system, which might afford some guidance for the synthesis of other inorganic nanotubes.

Construction of Ce(OH)4nanostructures from 1D to 3D by a mechanical force-driven method

“…The shape transformation was mainly due to a combination of an acid-assisted etching process and an oxidation-reduction process. 56,57 To further verify the function of the acid in our experiment, we have performed a contrast experiment. With the aid of acid and oxygen in the atmosphere, the solid nanoparticles have turned into hollow structures ( Fig.…”

Synthesis, Characterization, and Application of 1-D Cerium Oxide Nanomaterials: A Review

“…Chen et al . [24] studied three different ways for the formation of ceria nanotube on the basis of the Kirkendall effect (denoted as K-type), Template (T-type), and lamellar rolling (L-type). The K-type Ce-NT had been prepared by congregating Kirkendall voids and subsequent calcinations were acquired in the presence of air at 600 °C for 4 h. In addition, T-type and L-type nanotubes had been obtained without any calcination.…”

Tuning the Morphology of Metal Oxides for Catalytic Applications

“…315 A new route taking the advantage of the Kirkendall effect has been used to synthesize CeO 2 nanotubes. 316 However, the diameters of these ceria nanotubes are typically in the range of 200-1000 nm, too large to have appreciable impact on their catalytic properties. [317][318][319] Synthesis of single-crystalline and small-sized ceria nanotubes is still difficult, and most synthetic approaches are either time-consuming or involving complicated procedures with very low yield.…”