Synthesis and characterization of Mg۱-xNixAl۲O۴ and their photocatalytic behaviors towards Congo red under UV light irradiation

In this paper, MgAl۲O۴ nanoparticles were synthesized by the Sol-gel auto combustion method and were doped with different concentrations of Ni۲+ (x= ۰, ۰.۱, ۰.۰۵, and ۰.۰۳). By this method, a novel photocatalyst which had better decolorization percentages of Congo redcompared to MgAl۲O۴ was produced. The MgAl۲O۴ samples were calcinated at ۱۰۰۰ ۰C. The samples obtained were characterized by X-ray diffraction (XRD), SEM, FT-IR, EDX, and ICP-AES. The photocatalytic activity of MgAl۲O۴ samples were evaluated by UV-Vis spectroscopy and diffuse reflectance spectra (DRS) to confirm the performance rate of the photocatalyst. Also, the photocatalytic properties were investigated in the presence of UV light, certain amounts of photocatalysts, and Congo reddye. The best- obtained results of the photocatalytic activity among the prepared samples were Mg۰.۹Ni۰.۱Al۲O۴ because this photocatalyst had a removal conversion of ۹۹.۳ % of the dye after ۹۰ min, which was better than other photocatalysts in similar conditions. Mg۰.۹Ni۰.۱Al۲O۴ was used as a photocatalyst five successfully times without any changes or loss of its high photocatalytic activity for this process. In this project, we used Ni۲+ to dope MgAl۲O۴ nanoparticles. The results decolorization percentages of Congo redshowed that Mg۰.۹Ni۰.۱Al۲O۴ hadbetter efficiency compared to MgAl۲O۴, and other photocatalysts.

Keywords:

Congo Red , MgAl۲O۴ , nanoparticles , Photocatalyst , Sol-gel auto combustion method