Synthesis and Characterization of Pure and Manganese (Mn) Doped Zinc Oxide (ZnO) Nanocrystallites for Photocatalytic Applications

Abstract

In this work, pure and manganese (Mn) doped zinc oxide (ZnO) nanocrystallites are synthesized using a sol-gel technique. 0.25 M solution of zinc nitrate hexahydrate is prepared in 50 ml of DI water with stirring condition. An equimolar citric acid (0.25 M) solution is added slowly into the above solution and stirred for 2 hrs. at 70oC. The obtained gel is dried for 3 hrs in hot air oven at 120°C. Further, the nanoparticles are annealed at 400°C and the samples are characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, photoluminescence spectroscopy (PL) and photo catalytic studies. XRD analysis deciphered the polycrystalline hexagonal of the samples and the crystallites sizes are observed to be 18 nm and 42 nm for the pure and Mn doped ZnO particles, respectively. FE-SEM studies demonstrate that the crystallites are spherical in shape with agglomeration. PL studies reveal the emission bands at 490 nm for pure ZnO and 530 nm for Mn doped ZnO. The photocatalytic studies determine the photocatalytic performance of pure ZnO NPs and Mn doped ZnO NPs under the UV light irradiation (365 nm and 125 W) in which, the pure ZnO degrades MB dye more efficiently than Mn doped ZnO.