Abstract: The application of Au nanoparticles (AuNPs) modified CeO₂(Au/CeO₂) as an antioxidant has great potential in the field of life health, and exploring the antioxidant activities of Au/CeO₂ prepared by different methods is helpful for optimizing the property of Au/CeO₂. In this work, two different Au-modified CeO₂ were synthesized by modifying AuNPs on the surface of CeO₂ nanorods using sol-immobilized and deposition methods, respectively. The antioxidant activities of two different Au/CeO₂ were studied by UV method in the MV-Fenton system, and the results showed that the antioxidant activity of Au/CeO₂ by sol-immobilized method (S-Au/CeO₂) was higher than that of Au/CeO₂ by deposition method (D-Au/CeO₂). The affecting factors on the differences between the antioxidant properties of the two Au/CeO₂ were further investigated. We suppose that the surface structure of CeO₂ may be damaged in the process of preparation by deposited method, which resulted in the lower antioxidant activity of D-Au/CeO₂. In addition, the electron transfer between sol-immobilized AuNPs and CeO₂ contributed to the higher antioxidant activity of S-Au/CeO₂. These results have great significance for the functional preparation and antioxidant property regulation of Au/CeO₂.

Key words: Au/CeO₂, sol-immobilized, deposition method, antioxidant activity, surface structure