Haloperoxidase Mimicry by CeO2-x Nanorods of Different Aspect Ratios for Antibacterial Performance

Cerium oxide nanorods as haloperoxidase started to gain attention due to their great potential as a biologically benign antifoulant. The antibacterial efficiency induced by haloperoxidase activity of cerium oxide nanorods with different aspect ratios is currently unexplored. Herein, the relationship between different aspect ratios, haloperoxidase activities, and antibacterial effects was systematically investigated. CeO2-x nanorods with different aspect ratios were synthesized by merely controlling NaOH concentrations via a traditional hydrothermal method. The CeO(2-x )nanorods exposed {110} facets and supplied the Ce3+ sites to ensure the haloperoxidase activities. The haloperoxidase activities of CeO2-x nanorods were varied with their aspect ratios because of their differences in Ce3+ concentration, oxygen vacancies, and band gap energies. More importantly, their antibacterial efficiency was in the same order as their haloperoxidase activity, indicating that natural intermediates (HOBr) are induced by the haloperoxidase mimicking activity to achieve antibacterial efficiency. This work provides a guide for improving antibacterial efficiency of cerium oxide nanorods by modulating their aspect ratios.