Albumen-assisted Synthesis of Nanocrystalline Nickel Ferrite Photocatalyst

2021 ◽  
Vol 14 (5) ◽  
pp. 437-444

Abstract: As a simple step to remove the polluting dyes in aqua ecosystem, NiFe2O4 nanoparticles well known for their ferromagnetic properties, low conductivity and high electrochemical stability were prepared by simple auto combustion method using egg white as fuel via green synthesis route. The structural, morphological and magnetic properties of prepared NiFe2O4 was analyzed. The desirable phase purity of the prepared spinel ferrite was deliberated by X-ray Diffractometer (XRD), Fourier Transform Infrared Spectrometer (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive and Vibrating Sample Magnetometer (VSM). XRD predicts the phase formation, particle size and lattice parameter of the spinel ferrite. The FTIR spectrum confirms the ferrite structure. The morphological and elemental analysis was made using SEM and EDAX. The hysteresis curve reveals the magnetic properties, such as remanence magnetization (Mr), coercivity (Hc) and saturation magnetization (Ms). The photocatalytic efficiency of the synthesized samples was determined from degradation of methylene blue dye. The whole process was monitored using spectrophotometer at regular intervals of time. The maximum photocatalytic degradation efficiency for NiFe2O4 is around 95.6 %. Keywords: NiFe2O4, Ferrite, Green synthesis, Egg white, Combustion, Photocatalyst.

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


2018 ◽  
Vol 550 ◽  
pp. 90-95 ◽  
Author(s):  
Nazia Yasmin ◽  
Iqra Inam ◽  
Iftikhar Ahmed Malik ◽  
Maria Zahid ◽  
Muhammad Naeem Ashiq ◽  
...  

2012 ◽  
Vol 10 (6) ◽  
pp. 1799-1807 ◽  
Author(s):  
Tamara Slatineanu ◽  
Eliano Diana ◽  
Valentin Nica ◽  
Victor Oancea ◽  
Ovidiu Caltun ◽  
...  

AbstractThe present study is reporting the influence of the chelating/combustion agents on the magnetic properties of Zn ferrite. Six chelating/combustion agents, citric acid, egg white, tartaric acid, glycine, glucose and urea, were used to obtain monophase zinc nanoferrite via a sol-gel auto-combustion method. The samples were subjected to a comparative study of structural features and magnetic properties by means of infrared spectroscopy, X-ray diffractometry, scanning electron microscopy and vibrating sample magnetometry. Significant influence of fuel and combustion mode was observed in the magnetic behavior of as-obtained samples. Values of the structural parameters were discovered to vary as a function of fuel choice, and to obtain crystallite size between 38 and 62 nm, inversion degree between 0.239 and 0.807, lattice parameter between 8.4125 and 8.4432 Å. The optimization of sol-gel method synthesis of zinc ferrite nanoparticles by chosing the appropriate fuel is providing structural and magnetic properties of zinc nanoferrite as potential materials to be used in biomedical applications.


2018 ◽  
Vol 916 ◽  
pp. 91-95
Author(s):  
Beh Hoe Guan ◽  
Muhammad Hanif bin Zahari ◽  
Kean Chuan Lee

Spinel ferrite with the chemical formula of Mn0.5Zn0.5LaxFe2-xO4(x= 0.02, 0.04, 0.06, 0.08, 0.10) were prepared by a sol-gel auto-combustion method. The effect of the rare-earth substitution on the microstructural properties of the synthesized powders were investigated through X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), while for the magnetic properties, vibrating sample magnetometer (VSM) measurements were made. XRD patterns revealed characteristic peaks corresponding to spinel Mn-Zn ferrite structures with accompanying secondary phases, such as Fe2O3and LaFeO3. The initial addition of La3+into the spinel ferrite system resulted in an initial spike of the lattice parameter and crystallite size before proceeding to decrease as the rare-earth content continues to decrease. FESEM micrographs reveals agglomerated particles with considerable grain size distribution. The magnetic properties, especially the saturation magnetization,Ms, was found to decrease with each increase in La3+substitution. The research findings revealed the critical influence of the La3+substitution towards the overall structural and magnetic properties of the Mn-Zn ferrite samples.


2015 ◽  
Vol 29 (26) ◽  
pp. 1550151 ◽  
Author(s):  
B. Rajesh Babu ◽  
K. V. Ramesh ◽  
M. Sivaram Prasad ◽  
Y. Purushotham

Nanocrystalline Ni–Zn–Al spinel ferrite was synthesized via citrate-gel auto combustion method. The as-prepared powders have been separated into two batches in which one batch of powders were sintered at 1000[Formula: see text]C for 4 h and the other batch were pressed into pellets and were sintered at the same temperature. Sintering of the samples was done in air atmosphere followed by natural cooling to room temperature. The heat treated powders have then been characterized using TG–DTA, XRD, SEM and TEM for thermal, structural and microstructural aspects while the DC electrical resistivity measurements were carried out on the sintered pellets. The X-ray diffraction patterns displayed the formation of the spinel phase for all powders and the lattice parameter was obtained using Bragg’s law. The crystallite size for all compositions were found to be in nano dimensions and obtained from the Williamson–Hall method. TG–DTA analysis of the undoped [Formula: see text] indicated the formation of the spinel phase is around 400[Formula: see text]C while almost uniform microstructure with a more or less spherical grains has been noticed in the SEM micrograph. An enhancement in the DC electrical resistivity ([Formula: see text]-cm) has been observed in [Formula: see text] synthesized using this technique in comparison with that processed through conventional ceramic technique and a modification in the resistivity has been observed on substituting [Formula: see text] in place of [Formula: see text]. High electrical resistivity makes these ferrites suitable for high-frequency applications due to possible reduction of the eddy current losses. The observed variation in resistivity has been discussed on amendments in structure, microstructure and unavailability of [Formula: see text] ions with increasing [Formula: see text] ions in the light of existing understanding. The decrease in resistivity with increasing temperature confirms the semiconducting behavior of all samples. Activation energies for conduction were obtained from the slope of the log [Formula: see text] versus [Formula: see text] plots and observed to be in the range of 0.6–0.45 eV. The variation in the activation energy for conduction followed a similar trend as the DC resistivity. The drift mobility decreases with increasing [Formula: see text] ions concentration and increases with increasing temperature.


2021 ◽  
Author(s):  
Jiali Song ◽  
Zhi Wang ◽  
Yu Gao

Abstract Nanocrystalline Li 0.35 Ni 0.3 Fe 2.35 O 4 ferrites were prepared at different annealing temperature by sol-gel auto-combustion method. The effects of the annealing temperature on the structure and magnetic properties of the synthesized Li-Ni ferrites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR) and Squid-VSM. Rietveld refinement of the X-ray diffraction data confirmed the occurrence of phase transition from α-spinel to β-spinel, from which the ideal cation occupation and lattice parameter can be obtained. The grain size increased significantly with annealing temperature. The variation of saturation magnetization can be well explained in terms of the occupation of ions in tetrahedron and octahedron. The coercivity initially increased and later decreased significantly from 115 to 37 Oe with the increase of annealed temperature which could be attributed the fact that the 600℃-annealed grain size is close to transition size from single to multidomain region.


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