A novel green synthesis and characterization of tetragonal-spinel MgMn2O4nanoparticles by tragacanth gel and studies of its photocatalytic activity for degradation of reactive blue 21 dye under visible light

In this work, Magnesium manganite (MgMn 2 O 4 ) tetragonal-spinel nanoparticles were successfully synthesized by tragacanth gel through the easy and inexpensive novel sol-gel method. This technique has many strong points such as facile, economical, non-toxic and quickness in comparison with other methods. The magnesium manganite nanoparticles characterized by energy dispersive x-ray analysis (EDX), powder x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transforms infrared spectroscopy (FTIR), UV-Visible Diffuse Reflectance spectroscopy (DRS), and percent of dye degradation which was followed by UV–Visible spectroscopy. The XRD pattern confirmed the formation of spinel tetragonal structure of MgMn 2 O 4 nanoparticles with a crystallite size of 10 nm. The MgMn 2 O 4 NPs expressed high photocatalytic activity for degradation of reactive blue 21 dye at room temperature in aqueous solution so that 95% of RB21 was degraded in 60 min. The spinel MgMn 2 O 4 NPs reusability was examined by administering the degradation of RB21 dye with the spent catalyst, and it was considered that the photocatalyst exhibits a small decrease in its activity after the four recycles.