A lanthanum oxide (La₂O₃)-ZnO nanostructured material was synthesized in the proposed study with different La₂O₃ concentrations, 0.001 g to 5 g (named So to S7), using the combustion method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transformation infrared spectroscopy (FT-IR) were utilized for investigating the structure, morphology, and spectral studies of the La₂O₃- ZnO nanomaterials, respectively. The results obtained from previous techniques support ZnO’s growth from crystalline to nanoparticles’ fine structure by changing the concentrations of lanthanum oxide (La₂O₃) dopants in the host matrix. The percentage of ZnO doped with La- influences the ZnO photocatalytic activity. SEM analysis confirmed the grain size ranged between 81 and 138 nm. Furthermore, UV-Vis diffuse reflectance spectroscopy was performed to verify the effects of La₂O₃ dopants on the linear optical properties of the nano-composite oxides. There was a variation in the energy bandgaps of La₂O₃-ZnO nanocomposites, increasing the weight concentrations of lanthanum dopants. The AC electrical conductivity, dielectric properties, and current–voltage properties support the enactment of the electrical characteristics of the ZnO nanoparticles by adding La₂O₃. All the samples under investigation were used for photodegradation with Rhodamine B (RhB) and Methylene Blue (MB). In less than 30 min of visible light irradiation, S4 (0.5 g) La₂O₃-ZnO reached 99% of RhB and MB degradation activity. This study showed the best photocatalytic effect for RhB and MB degradation of 0.13 and 0.11 min⁻¹ by 0.5 g La₂O₃-ZnO. Recycling was performed five times for the nanocatalysts that displayed up to 98 percent catalytic efficiency for RhB and MB degradation in 30 min. The prepared La₂O₃-ZnO nanostructured composites are considered novel candidates for various applications in biomedical and photocatalytic studies.

An efficient and environmentally friendly combustion technique was employed to produce ZnO nanopowders with different Eu concentrations (from 0.001 g to 5 g). The structural morphology of the Eu₂O₃-ZnO nanocomposites was examined using XRD, SEM, and infrared spectroscopy (FT-IR). In addition, UV-Vis diffuse reflectance spectroscopy was also used to investigate the effects of europium (Eu) dopant on the optical behaviors and energy bandgaps of nano-complex oxides. The photocatalytic degradation efficiency of phenol and methylene blue was investigated using all the prepared Eu₂O₃-ZnO nanostructured samples. Photocatalytic effectiveness increased when europium (Eu) doping ratios increased. After adding moderate Eu, more hydroxyl radicals were generated over ZnO. The best photocatalyst for phenol degradation was 1 percent Eu₂O₃-ZnO, while it was 0.5 percent Eu₂O₃-ZnO for methylene blue solutions. The obtained Eu₂O₃-doped ZnO nanostructured materials are considered innovative, promising candidates for a wide range of nano-applications, including biomedical and photocatalytic degradation of organic dyes and phenol.