Zinc oxide and nickel ferrite nanocomposite as an efficient photocatalyst for crystal violet dye degradation

Abstract

In the present study, photocatalytic activity of NiFe2O4/ZnO nanocomposite was studied for the degradation of crystal violet dye. Microwave assisted green synthesis method was used for the synthesis of ZnO nanoparticles (NPs). Sol-gel auto-combustion method was used to synthesize NiFe2O4 (NiF) NPs. NiF/ZnO nanocomposite was synthesized through solid-state reaction method. Structural phase was confirmed through X-ray diffraction studies. ZnO NPs were found in wurtzite hexagonal structure whereas cubic spinel structure was found for NiF. NiF/ZnO nanocomposite was observed in both phases. The crystallite size was found to be 31 ± 1, 18 ± 2 and (95 ± 1)/(98 ± 1) nm, for NiF, ZnO and NiF/ZnO nanocomposite, respectively. The optical band gap was determined through UV–Visible spectroscopy and is found to be 1.67 ± 0.03, 2.70 ± 0.08 and 1.70 ± 0.05 eV for NiF, ZnO and NiF/ZnO nanocomposite, respectively. Infrared study of NiF showed the tetrahedral and octahedral band whereas for ZnO the characteristic band was observed. FESEM micrographs of NiF/ZnO nanocomposite showed the formation of agglomerated spherical particles and very less number of rod-like grains indicating the formation of NiF/ZnO nanocomposite. The photocatalytic activity of NiF, ZnO and NiF/ZnO nanocomposite for the degradation of crystal violet dye was studied. It was found that NiF, ZnO and NiF/ZnO nanocomposite showed 89 %, 90.46 % and 87.21 % degradation rate in 60, 120 and 50 min respectively.