LAUSR

Nanoparticles of CeO2, with rod- and cubic-morphology, were synthesized by hydrothermal method and compared with commercial polyhedral ceria particles. Comparison of the synthesized CeO2 with the commercial powder revealed the influence of its defectivity with the absorption edge energy. The defectivity of CeO2 has also been determined in correlation with the photocatalytic performance of CeO2 per unit particles area, under narrow band UV-light condition. Analysis of the photocatalytic performance of the synthesized and commercial CeO2, as well as the reference TiO2 powder, revealed an enhancement in the decolorization of methylene blue dye (MB) with pH. The improvement in photocatalysis was associated with the surface charge condition of CeO2 particles, which controls the adsorption of molecules during the process. Furthermore, it was observed that the highly negative surface charge of cubic-morphology CeO2 favored the decolorization of MB, despite the low Brunauer-Emmett-Teller surface area. The photoelectrochemical study of ceria electrodes revealed a low photopotential compared to that of TiO2, the impact of which leads to a worse photocatalytic performance of CeO2 compared to TiO2.