Materials Research Express (Jan 2023)

Lanthanum substituted Ni-Zn ferrite (Ni0.75Zn0.25Fe2O4) nanomaterial and its composite with rGO for degradation of binary dyes under visible light irradiation

  • Workneh Mechal Shume,
  • Enyew Zereffa,
  • C R Ravikumar,
  • Sanaulla Pathapalya Fakrudeen,
  • Kah-Yoong Chan,
  • H C Ananda Murthy

DOI
https://doi.org/10.1088/2053-1591/acd50e
Journal volume & issue
Vol. 10, no. 5
p. 055005

Abstract

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Magnetically separable lanthanum modified Ni-Zn spinel ferrite nanoparticles (Ni _0.75 Zn _0.25 La _0.06 Fe _1.94 O _4 ) and Ni _0.75 Zn _0.25 La _0.06 Fe _1.94 O _4 @rGO nanocomposites were successfully synthesized by the sol-gel auto-combustion and sonication methods respectively, for the degradation of binary organic pollutants. The results of x-ray Diffraction (XRD) analysis confirmed the formation of the face centered cubic (FCC) ferrites with the crystallite sizes ranging between 29.74 and 44.94 nm. The optical bandgap of the nano-composite was found to be 1.691 eV as revealed by the diffused reflectance spectral (DRS) study. The formation of the desired composition nanoparticles with a nearly spherical shape and their homogeneous distribution on sheets of rGO were verified by the scanning electron microscopy (SEM) coupled with energy dispersive x-ray (EDAX) instrument. The HR-TEM/SEAD analysis also revealed the formation of spherical polycrystalline nanoparticles and their uniform dispensability with a little agglomeration on the sheet of rGO. The degradation studies were conducted using binary dyes (MB and MO) under the irradiation of visible light in the presence of peroxide. The effects of catalyst dose, irradiation time, initial dye concentration, pH value, and recyclability of nanocomposites have been systematically studied. The findings showed that as compared to La ^3+ substituted Ni-Zn ferrite nanoparticles (78% for MB and 85 % for MO), the magnetic Ni _0.75 Zn _0. 25 La _0.06 Fe _1.94 O _4 @rGO nanocomposite exhibited as a potential photocatalyst towards the simultaneous degradation of both dyes (95% for MB and 98% MO) within 40 min under the optimized conditions. The hydroxyl radical (·OH) play a key role for Ni _0.75 Zn _0.25 La _0.06 Fe _1.94 O _4 @rGO nanocomposite photocatalyst for photocatalytical degradation of the binary dyes (methyl orange and methylene blue).

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