TiO2@CeOx Core鈥揝hell Nanoparticles as Artificial Enzymes with Peroxidase-Like Activity

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• 作者：Luca Artiglia ; Stefano Agnoli ; Maria Cristina Paganini ; Mattia Cattelan ; Gaetano Granozzi
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：November 26, 2014
• 年：2014
• 卷：6
• 期：22
• 页码：20130-20136
• 全文大小：355K
• ISSN：1944-8252

文摘

The Ce⁴⁺鈫?Ce³⁺ redox switch is at the basis of an all-inorganic catalytic cycle that is capable of mimicking the activity of several natural redox enzymes. The efficiency of these artificial enzymes (nanozymes) strongly depends on the Ce⁴⁺/Ce³⁺ ratio. By capitalizing on the results obtained on oxide/oxide model systems, we implemented a simple and effective procedure to obtain conformal TiO₂@CeO_x core鈥搒hell nanoparticles whose thickness is controlled with single-layer precision. Since the Ce³⁺ species are stabilized only at the interface by the electronic hybridization with the TiO₂ states, the modulation of the shell thickness offers a simple method to tailor the Ce⁴⁺/Ce³⁺ ratio and therefore the catalytic properties. The activity of these nanoparticles as artificial peroxidase-like enzymes was tested, showing exceptional performances, even better than natural horseradish peroxidase enzyme. The main advantage with respect to other oxide/oxide nanozymes is that our nanoparticles, having a tunable Ce⁴⁺/Ce³⁺ ratio, are efficient already at low H₂O₂ concentrations.

Keywords:

titanium dioxide; cerium oxide; interface hybridization; core鈭抯hell; artificial enzyme; peroxidase