Enhanced Artificial Enzyme Activities on the Reconstructed Sawtoothlike Nanofacets of Pure and Pr-Doped Ceria Nanocubes

In this work, a simple one-step thermal oxidation process was established to achieve a significant surface increase in {110} and {111} nanofacets on well-defined, pure and Pr-doped, ceria nanocubes. More importantly, without changing most of the bulk properties, this treatment leads to a remarkable boost of their enzymatic activities: from the oxidant (oxidase-like) to antioxidant (hydroxyl radical scavenging) as well as the paraoxon degradation (phosphatase-like) activities. Such performance improvement might be due to the thermally generated sawtoothlike {111} nanofacets and defects, which facilitate the oxygen mobility and the formation of oxygen vacancies on the surface. Finally, possible mechanisms of nanoceria as artificial enzymes have been proposed in this manuscript. Considering the potential application of ceria as artificial enzymes, this thermal treatment may enable the future design of highly efficient nanozymes without changing the bulk composition.

Automated summary

A simple one-step thermal oxidation process was established to increase {110} and {111} nanofacets on ceria nanocubes, leading to improved enzymatic activities. The enhancement may be attributed to the sawtoothlike {111} nanofacets and defects that facilitate oxygen mobility and the formation of oxygen vacancies on the surface, without changing the bulk properties. Additionally, possible mechanisms of nanoceria as artificial enzymes were proposed in this study, suggesting the potential for future design of highly efficient nanozymes.