Shape-selective synthesis and optical performance of ceria nanocrystal/graphene hybrid composites

The morphology of CeO2 nanomaterials determines their properties and synthesis of well dispersed CeO2 nanocrystals with desired morphology is thus crucial for their applications. In this paper, we report the successful synthesis of CeO2 nanocrystals with different morphologies anchored on graphene hybrid composites by a hydrothermal method. Nanorods/graphene (NRs-G), nanoparticles/graphene (NPs-G) and nanocubes/graphene (NCs-G) have been selectively synthesized by optimizing experimental conditions. These nanocrystals show different exposed crystal planes and the size or morphology of the loaded CeO2 can be controlled by the alkali concentration and reactive temperature, as well as the adding of GO or not. In addition, significant changes in the photoluminescence (PL) spectra intensity and position (energy) have been observed in the synthesized samples, which depend on the morphology and size of the loaded CeO2. These interesting phenomena can be easily rationalized by the difference of oxygen storage capacity (OSC) of samples.