Search

Cadmium ferrites belong to normal spinel ferrites, and they exhibit interesting electrical, magnetic, and optical properties. The pure and cerium-doped cadmium ferrites CdFe2−xCexO4 (x = 0.0, 0.125, 0.250, 0.375, 0.5) were synthesized by a chemical co-precipitating technique using sodium hydroxide as a co-precipitating agent. The structures and phase purity of fabricated nanomaterials were analyzed by X-ray diffraction (XRD). The crystallite size for all the prepared nanomaterials was in the range of 28–46 nm. The lattice constant and unit cell volume were found to decrease with the increasing concentration of Cerium, which was confirmed by the peak shift in the XRD pattern. The X-ray density for all nano ferrites increased with the enhancement of cerium composition. The resistivity of the nanomaterials has random behavior with the enhancement of cerium composition for a temperature, but the value of resistivity at x = 0.125 has the lowest value and at x = 0.375 has the highest value for almost all temperatures. For specific concentrations, a decreasing trend of resistivity of fabricated materials was found with an increment of temperature. The activation energies were also calculated, and it increased for x = 0.125 and then decreased for all the nanomaterials. For the confirmation of the M–O bonds, FTIR analysis of all the nano ferrites was also performed. The analysis shows a higher frequency absorption band in the range of 531.24–534.84 cm−1. This absorption band confirms that metal oxides are formed in all the synthesized nanoparticles. [ABSTRACT FROM AUTHOR]

Ho-substituted Li–Ni ferrites with composition L i 1.2 Ni 0.4 Ho x Fe 2- x O 4 ; 0≤ x ≤ 0.15 were synthesized by a self-ignited sol-gel process. An annealing temperature of 950 °C is estimated via thermal-gravimetric (TGA) analysis. X-ray diffraction (XRD) scans have confirmed the formation of the ferrite phase with a spinel structure in all samples. Substitution of Ho ions on the B-site significantly reduced the porosity from 38 -to 23% and the crystallite size from 23.4 -to 21.7 nm. Microstructural analysis revealed a denser structure with an increase in Ho content. Dielectric results showed that both the dielectric loss and dielectric constant depict a nonlinear variation with the addition of Ho. Complex impedance behavior with a single semicircle for all samples suggests the predominant effect of the grain boundary mechanism. The substitution of Ho ions in place of Fe ions significantly decreased the electrical conductivity. The anisotropic Ho3+ ions reinforce the L-S coupling which consequently enhanced the coercive force from 145 -to 389 Oe, and thus the anisotropy constant. [ABSTRACT FROM AUTHOR]

Cadmium ferrites belong to normal spinel ferrites, and they exhibit interesting electrical, magnetic, and optical properties. The pure and cerium-doped cadmium ferrites CdFe2−xCexO4 (x = 0.0, 0.125, 0.250, 0.375, 0.5) were synthesized by a chemical co-precipitating technique using sodium hydroxide as a co-precipitating agent. The structures and phase purity of fabricated nanomaterials were analyzed by X-ray diffraction (XRD). The crystallite size for all the prepared nanomaterials was in the range of 28–46 nm. The lattice constant and unit cell volume were found to decrease with the increasing concentration of Cerium, which was confirmed by the peak shift in the XRD pattern. The X-ray density for all nano ferrites increased with the enhancement of cerium composition. The resistivity of the nanomaterials has random behavior with the enhancement of cerium composition for a temperature, but the value of resistivity at x = 0.125 has the lowest value and at x = 0.375 has the highest value for almost all temperatures. For specific concentrations, a decreasing trend of resistivity of fabricated materials was found with an increment of temperature. The activation energies were also calculated, and it increased for x = 0.125 and then decreased for all the nanomaterials. For the confirmation of the M–O bonds, FTIR analysis of all the nano ferrites was also performed. The analysis shows a higher frequency absorption band in the range of 531.24–534.84 cm−1. This absorption band confirms that metal oxides are formed in all the synthesized nanoparticles. [ABSTRACT FROM AUTHOR]

In the present study, with the aid of the ultrasonication route the copper-doped cobalt chromium ferrite with graphitic carbon nitride (CoCrCuFe 2 O 4 @gCN, CCrCuFO@gCN) was prepared whereas the cobalt-chromium ferrite (CoCrFe 2 O 4 , CCrFO) and copper doped cobalt chromium ferrite (CoCrCuFe 2 O 4 , CCrCuFO) were synthesized via sol-gel approach. The gCN has a vast surface area, better stability, and a higher capability for the transfer of electrons during photocatalysis. Prepared products were characterized by several standard techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy measurements (UV–Vis). The crystallite size of CCrFO and CCrCuFO were 16.3 nm and 15.8 nm respectively calculated by Debye Scherer formula. Under sunlight, Crystal violet, Congo red, Methyl orange, Methyl blue, and Benzoic acid were degraded. Under the same conditions, the CoCrCuFe 2 O 4 @gCN exhibited 90.2 % degradation of Crystal violet, 90.1 % of Congo red, 92.2 % of Methyl orange, 91.1 % of Methyl blue, and 57.9 % of Benzoic acid. During the photo-degradation of pollutants, photoactive species like hydroxyl radicals, holes, and electrons were found to be the major contributors. The CCrCuFO@gCN composite showed higher photocatalytic degradation activity than pristine and doped materials due to its enhanced surface area. As the surface area of nanocatalysts increased, the recombining rate of electron/hole pair reduced, and hence the photocatalytic efficiency was boosted. The remarkable removal efficacy of CCrCuFO@gCN nanocomposite can be attributed to its large/massive surface area, 2D structure, and enhanced capacity to transport electrons of graphitic carbon nitride. For an efficient application in wastewater treatment, this work aims to encompass the new progress and new research directions of CCrCuFO@gCN under sunlight. • Simple facile route was adopted to prepare CoCrCuFe 2 O 4 @g-C 3 N 4 , a new photocatalyst. • Photodegradation of numerous organic effluents by CoCrCuFe 2 O 4 @g-C 3 N 4 was studied. • Mechanistic investigation of degradation has also been discussed. [ABSTRACT FROM AUTHOR]