Synthesis Of CeO₂ Nanostructures And The Effect Of The Exposed Facets On Their Enzyme-mimicking Activities

Nanomaterials can mimic different enzymes,catalyzing different reactions.In comparison with nature enzymes,nanoparticles are not only easy to fabricate,store and transport,but also able to maintain their catalytic performance under harsh conditions.Such enzyme-mimicking ability are employed in enzyme linked immunosorbent assay,molecule and ion detection,hazardous species degradation,etc.CeO₂ nanoparticles can mimic the superoxide dismutase,catalase and peroxidase.The mimicking abilities of CeO₂ nanoparticles was attributed to their partial reduced Ce³⁺inside the crystal structure.Herein,the author successfully synthesized CeO₂nanocubes and nanorods via hydrothermal reaction.With different characterizations,it was confirmed that these obtained CeO₂ nanostructures have the same level of Ce³⁺ions as well as the oxygen vacancy concentration.It was further discovered that these nanostructures have different morphologies,specific surface areas,exposed facets and microstrain levels.The author checked the abilities of these two CeO₂nanostructures that mimic the peroxidase and superoxide dismutase.The CeO₂nanocubes have by far better peroxidase-mimicking performance while the CeO₂nanorods have much better superoxide dismutase-mimicking ability.According to further analysis and simulation based on both molecule mechanics and density functional theory,the different exposed facets was found to be responsible for the performance difference of these two CeO₂ nanostructures.The surface area and microstrain are not main reasons for the catalytic performance difference.This research provides a new factor influencing the enzyme-mimicking performance of CeO₂ nanostructures.