Studying the Photocatalytic Activity of a Nanosized Powder and Fibers Based on Nickel–Zinc Ferrite

A nanosized powder and nanostructured fibers of nickel–zinc ferrite Ni_0.5Zn_0.5Fe₂O₄ have been synthesized. Using X-ray diffraction analysis, it has been proven that the synthesized samples correspond to the nickel–zinc ferrite phase. It has been found that the fibers based on nickel–zinc ferrite have higher crystal lattice parameter and crystallite size values than those of the synthesized nanosized powder. Scanning electron microscopy data have shown that the studied samples consist of nanosized particles with a size of 20–60 nm for the powder and 20–40 nm for the fibers. The optical diffuse reflectance method has been used to determine the band gap for the Ni_0.5Zn_0.5Fe₂O₄ samples: 1.58 and 1.67 eV for the fibers and the powder, respectively. The photocatalytic degradation of methylene blue under the action of Ni_0.5Zn_0.5Fe₂O₄ samples of the different morphologies has been studied. It has been found that the nanostructured Ni_0.5Zn_0.5Fe₂O₄ fiber sample exhibits a higher photocatalytic activity, because the degree of degradation of methylene blue is 26% for the nanofibers and 18% for the nanopowder.