Novel metal oxides have been studied worldwide due to their potential uses in ecological refinement, particularly to eliminate organic impurities present in water. In this work, we report the preparation of Ni1-xCoxAl2O4-δ (where x=0, 0.05, 0.10, 0.15 and 0.20) nanoparticles by simple chemical precipitation route. The as-synthesized spinel particles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), particle size analysis, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), UV-Vis Spectroscopy (UV) and Photo Luminescence (PL) Spectroscopy techniques. The XRD results affirmed the development of the cubic structure in all the samples. FT-IR confirmed the presence of the M-O bond. Particle characteristics statistics showed the existence of particles in the range of 36-741 nm range. SEM analysis strengthened the presence of various sized grains (nano and micron) in the samples. EDX analysis affirmed the existence of an appropriate amount of elements (Ni, Al, Co and O) in all the samples. The band gap of Co doped NiAl2O4 was in between 2.8 – 3.0 eV, which was in line with the reported data. The PL spectra exhibited a strong peak at around 450 nm in the samples. From UV studies, the λmax was around 310 nm in all the prepared samples. The photoluminescent characteristics of the samples were confirmed by PL studies and their photoemission was found at 437 nm. Among the samples studied, the parent NiAl2O4 shows more efficiency in degrading the malachite green (MG) dye than other Co doped NiAl2O4 photocatalysts under the irradiation of visible light at the wavelength of 616nm at normal temperature. Manuscript profile

In this study, we discuss the wet chemical synthesis and experimental analysis of zinc doped Gd2O3(Gd2-xZnxO3-δ) nanoparticles where, x=0, 0.1, 0.2, 0.3, 0.4, and 0.5. The cubic crystalline structure is derived from XRD results and the existence of metal-oxide bond has been confirmed from FTIR studies. According to SEM and PSA analysis, the produced nanoparticles are found to be of nano size. The EDX data verified the presence of Gd, Zn, and O in the samples. Based on UV-visible spectroscopy, the band gap and λmax values were computed. In an aqueous medium and under UV light irradiation, the photodegradation of Rhodamine B over Zn doped Gd2O3 nanoparticles was studied. It was observed that Gd1.50Zn0.50O3-δ has exhibited 82% of photo-degradation of the dye solution which further increased to 96% because of increasing the catalyst loading. The effect of pH and the concentration of the dye are also reported. According to the kinetic analysis, the photocatalysis process followed a pseudo-first-order kinetic model. A radical scavenger technique was used to further examine and identify the function of photoactive species. Manuscript profile