Lanthanide oxide doped zinc oxide: effective photocatalysts for the degradation of diesel in seawater under visible light irradiation

Nanocrystalline lanthanide oxide doped ZnO has been prepared by a simple and efficient technique for exhibiting an enhanced visible light photocatalytic activity. The prepared photocatalysts were characterized by SEM, XRD and UV–Vis DRS analysis. XRD data showed that the particles of samples were highly nanosized and crystalline. The sizes of Yb2O3/ZnO, Er2O3/ZnO and Pr6O11/ZnO nanoparticle were 40.97, 40.94 and 51.18 nm and found to be mixed morphology. Six factors such as dosage of photocatalysts, coupling ratio of lanthanide oxide and ZnO, initial concentration of diesel, concentration of H2O2, illumination time of visible light and pH value were changed in order to test the photocatalytic activity and efficiency of reaction. The enhanced photocatalytic activity was due to the presence of f shells in the lanthanide oxide crystal lattice which delays the process of recombination of electron hole pair. According to the results, diesel removal was