Tailoring the photo-Fenton activity of spinel ferrites (MFe₂O₄) by incorporating different cations (M = Cu, Zn, Ni and Co) in the structure

Abstract

Magnetic bimetallic nanospinels (MFe 2 O 4 ; M=Cu, Zn, Ni and Co) of size ranging between 15-30 nm were synthesized by facile and viable sol-gel method. The analysis of Fourier Transform Infrared Spectra of all the samples demonstrated formation of M-O bond in spinel structure. Structural exploration of all the nano materials using Powder X-Ray Diffraction and High Resolution Transmission Electron Microscopy revealed formation of single phase cubic spinel structure. All the materials exhibited magnetic temperament with high surface area (92-151 m 2 /g). Furthermore, band gap calculated from diffuse reflectance spectra was quite narrow (1.26-2.08eV) for all the samples, hence ferrites could act as visible light driven photocatalyst.The prepared nanospinels were proposed to be promising heterogeneous photo-Fenton catalyst under visible light for the degradation of organic pollutants. The catalytic results revealed that rate of reaction was significantly influenced by the cation in the spinel structure as degradation order was observed to be CuFe 2 O 4 (k=0.286 min -1 ) >ZnFe 2 O 4 (k=0.267 min -1 ) > NiFe 2 O 4 (k=0.138 min -1 ) > CoFe 2 O 4 (k=0.078 min -1 ). The reaction conditions were optimized for all the ferrites as the photodegradation was influenced by ferrite dosage (0.25-1.00 g/L), pH (2)(3)(4)(5) and H 2 O 2 concentration (4-27 mM). The experimental data disclosed that activity of ferrite was sensitive to sintering temperature. The materials displayed remarkable stability in the reaction as it could be magnetically separated using external magnet and recycled up to 4 consecutive cycles. There was no significant loss in activity of all the material demonstrating an excellent ability of ferrites to remove organic pollutants from wastewater.

Comparison Study of Structural and Magnetic Properties of Magnesium-Substituted Nickel–Zinc Ferrites Synthesized by Solid-State and Sol–Gel Routes

“…The presence of cobalt also increases the permeability and low loss factor at high frequency [7]. Similar doping of copper and magnesium substitution of Ni-Zn ferrite also show significant results in dielectric and magnetic property changes [8][9][10]13].…”

Spinel Ferrite Mediated Photo‐Fenton Degradation of Phenolic Analogues: A Detailed Study Employing Two Distinct Inorganic Oxidants

“…[30] The particle size examined using high resolution transmission electron microscopy (HRTEM, FEI Tecnai [G2 F20] operating at 200 keV) suggested that the samples were in the range of 15-30 nm. [30] The chemical composition and elemental distribution of materials was examined using an adjacent EDX system which suggested proper stoichiometric ratio of all elements. The crystal structure of magnetic materials was further analyzed by powder X-ray diffraction (XRD, Bruker model, D8 Advance) with CuK α radiation of 1.54 A in the range of 20-80 .…”

“…The synthesis and complete characterization of all photo-catalysts used in the present analysis has already been discussed in a previous report. [30] Briefly, all magnetic photo-catalysts were synthesized using sol-gel methodology and the raw samples were annealed at 400 C. Fourier transform infrared spectra of all samples recorded using Perkin Elmer spectrometer over a range of 800-400 cm À1 exhibited two elementary absorption peaks corroborating to the spinel structure of ferrites. [30] The particle size examined using high resolution transmission electron microscopy (HRTEM, FEI Tecnai [G2 F20] operating at 200 keV) suggested that the samples were in the range of 15-30 nm.…”

“…[30] Briefly, all magnetic photo-catalysts were synthesized using sol-gel methodology and the raw samples were annealed at 400 C. Fourier transform infrared spectra of all samples recorded using Perkin Elmer spectrometer over a range of 800-400 cm À1 exhibited two elementary absorption peaks corroborating to the spinel structure of ferrites. [30] The particle size examined using high resolution transmission electron microscopy (HRTEM, FEI Tecnai [G2 F20] operating at 200 keV) suggested that the samples were in the range of 15-30 nm. [30] The chemical composition and elemental distribution of materials was examined using an adjacent EDX system which suggested proper stoichiometric ratio of all elements.…”

Photocatalytic degradation of organic pollutant using Copper substituted calcium ferrite

“…The ferrites has an advantage of displaying the optical absorption for the low energy photons and of exhibiting the well suited electronic structure desirable for photocatalytic applications .Additionally the spinel related oxide photocatalysts exhibit enhanced efficiency due to the available extra catalytic sites of their crystal lattices. CaCuFe2O4 is a semiconductor spinel ferrite, with high chemical stability which makes it a good applicant for visible light responsive photocatalytic material [7][8][9][10]. There are several methods like the hydrothermal, ceramic, auto-combustion, mechanical milling, Solgel and co-precipitation techniques by which ferrite nanoparticles are usually prepared.…”