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

Abstract

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.

Fe3O4-TiO2 Thin Films in Solar Photocatalytic Processes

“…It can be noticed that materials shown in Table 2 exhibit an indirect bandgap smaller than the direct band gap, suggesting that the fundamental bandgap for these materials could be considered as an indirect bandgap [ 44 , 45 ]. The direct or indirect nature of the bandgap transition is an essential parameter of semiconductors for photocatalytic applications.…”

Shaddock peel-loaded CeO2 composites with peroxidase-like activity for dye degradation and trace detection of ascorbic acid

“…15,16 However, the catalytic activities of bare ceria are still moderate. Till now, numerous strategies have been developed to modulate the activities of nanoceria such as surface modification, 17,18 doping transition metals [19][20][21][22][23] and regulating morphology and size. 24,25 Zhao found that fluoride-capped nanoceria can significantly improve the oxidase-like activity of nanoceria, which stemmed from the increase of the concentration of Ce 3+ and the accompanying oxygen vacancies upon adding F À .…”

Modulating Ce3+ Sites in Ce‐Zr Oxide Nanocatalysts through Protamine Biomineralization for Organophosphate Dephosphorylation

“…Ceria can exist in dual oxidation states as Ce 3+ and Ce 4+ , enabling the ability to accommodate a high density of oxygen vacancies (Vo), which enhances the catalytic activity for OPD due to the cooperative redox property of Ce 3+ and Ce 4+ [1,6,9,11] . The addition of metal dopants to ceria has shown to improve Vo concentration and associated catalytic activity for the decomposition of OPs [1,12–15] …”

“…[1,6,9,11] The addition of metal dopants to ceria has shown to improve Vo concentration and associated catalytic activity for the decomposition of OPs. [1,[12][13][14][15] Various approaches can be applied to synthesize oxide nanocatalysts to tune structure and thus catalytic properties; however, the majority of preparation methods exhibit common drawbacks, such as complicated synthetic procedures and/or energy intensive processes. [6,[16][17][18][19] To alleviate these concerns, benign biomineralization-based methods have received increased attention as a straightforward and efficient synthesis approach for metal oxide catalysts.…”