Modulation of optical and photocatalytic properties by morphology and microstrain in hierarchical ceria nanostructures

In this work, we presented our effort to understand the effect of the operating parameters of the microwave oven (power and irradiation time) on the structural and morphological changes in ceria (CeO2) nanostructures. A series of controlled experiments were carried out to understand the crucial factors determining the formation of ceria nanostructures with spheres and rods like morphology. By adjusting the experimental parameters different ceria nanostructures such as spheres, cubes and rods were obtained. The variation of the lattice parameter and morphology of the prepared samples was discussed by structural studies. The W-H analysis was implemented to calculate the average crystallite size and microstrain. The influence of morphology and microstrain on the band gap energy, luminescence and photocatalytic activity of the synthesized samples was discussed. The observed variation in the band gap was explained based on the variation of the crystallite size. Also, the observed variation in the ratio of the intensity of band gap related emission (I-Bg) and defects related emission (I-def) was discussed. In addition, the enhanced photocatalytic performance of the prepared ceria nanostructures with different morphology was discussed.