Synthesis and characterization of cerium nanoparticles supported in graphene nanosheets.

In this work, we prepared 4% cerium nanoparticles supported on graphene nanosheets using the polymeric precursor method [1] to further investigate the electrocatalytic activity for H2O2 production from oxygen reduction reaction (ORR). Firstly, the electroactivity of graphene in the generation of H2O2 was analyzed. The measurements were performed using a rotating ring-disc electrode with a vitreous carbon disc (0.245 cm2 ) and gold ring (0.1866 cm2 ), efficiency factor: 0.28. For graphene nanosheets the H2O2 percentage was 86 % for two electrons transferred during ORR [2]. After the synthesis cerium nanoparticles supported in graphene nanosheets were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD). Analysis using SEM Figure 1A shows the nanoparticles of cerium on the graphene sheet (region highlighted in the figure). Characterization by X-ray diffraction analysis showed the presence of the CeO2 and CeO2-x phases in the cerium-based material as can be seen in Figure 1 B (insert) [3]. EDS showed the formation of the cerium nanoparticles on the graphene sheets. The results are promising for further application in the generation of H2O2, since using only graphene there is a high production of hydrogen peroxide, as cerium oxide is recognized as a good electrocatalyst for hydrogen peroxide production, the value of 86 % can be increased.