Formation of catalytically active CeO2 hollow nanoparticles guided by oriented attachment

Monodisperse CeO2 hollow nanoparticles were synthesized by a template-free hydrothermal method. The average size of the nanoparticles was measured to be 75 nm. Detailed experiments revealed that the CeO2 hollow nanoparticles were formed directly by oriented attachment of the initial CeO2 nanocrystals. Although Cu2+ was introduced into the system, the final CeO2 product was free of Cu species, which was confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectrum (XPS) studies. Furthermore, the as-prepared CeO2 hollow nanoparticles revealed superior catalytic activity toward CO oxidation compared to commercial CeO2 fine powders. It may provide a new path for the fabrication of inorganic hollow structures upon introducing alien metal ions.

► Hollow CeO2 nanoparticles were fabricated through a Cu2+-assisted hydrothermal route.
► The monodispersed CeO2 nanoparticles can form colloidal solution in water.
► The hollowing process can be attributed to the oriented attachment mechanism.
► CeO2 hollow nanoparticles show superior catalytic activity than commercial CeO2.