Synthesis of TiO2-NiFe2O4 nanocomposites using coprecipitation method as photocatalyst for methylene blue removal

Methylene blue, a basic dye that is important in the coloring process in the textile industry. However, the use of the dye Methylene blue is hazardous for the skin, the eyes, and swallowed. Three composition types of TiO2-NiFe2O4 nanocomposites (75:25, 50:50, and 25:75) had been synthesized using a simple coprecipitation method. The photodegradation and adsorption performance of the nanocomposites were also evaluated. Based on X-ray diffraction analysis, both the titania anatase and nickel ferrite spinel phases appeared in each nanocomposite’s diffraction pattern. The average crystallite size of the nanocomposites was 38 nm, 33 nm, and 41 nm for compositions 75:25, 50:50, and 25:75, respectively. The optimum photodegradation activity of TiO2-NiFe2O4 nanocomposites was achieved at composition 75:25 %mol with >99% methylene blue degraded during 120 minutes of UV irradiation time. However, all nanocomposites also have adsorption capability toward methylene blue with an optimum percentage of 98%. Therefore, TiO2-NiFe2O4 nanocomposites can be used either as photocatalysts or adsorbents for methylene blue removal in an aqueous solution.

The effect of alloying additives on the magnetic permeability and permittivity of ferrite spinel

Coatings made of the materials that effectively absorb radiation, e.g., ferrite materials, are used to reduce the level of electromagnetic radiation in rooms containing household or industrial equipment. It is known that significant dissipation of the radiation energy is provided by the thickness of the shielding coating which should be comparable to the length of the electromagnetic wave in the material which, in turn, significantly decreases at high values of the magnetic permeability and permittivity of the radio-absorbing material. Ferrite radio-absorbing coatings are characterized by the high heat resistance, low flammability and small (10 – 20 mm) thickness. However, at frequencies less than 40 MHz, plates with a thickness of more than 30 mm are to be used to provide the effective absorption, and the weight and cost of the coatings increase significantly. The results of studying the effect of the sintering temperature and micro-additives of titanium, calcium and bismuth oxides on the dielectric constant of Ni- and Mn-Zn radio-absorbing ferrites are presented. Reactively pure starting oxide components with a basic substance content of more than 99.6 % wt. were used to synthesize samples using traditional oxide technology. It is shown that alloying with bismuth and titanium oxides is rather effective for obtaining radio-absorbing ferrites with a combination of high values of the magnetic permeability and dielectric permittivity. The obtained results can be used in production of ferrite radio- absorbing materials operating in the megahertz range.

Influence of neodymium substitution on structural, magnetic and spectroscopic properties of Ni–Zn–Al nano-ferrites

The incorporation of Nd3+ in the Ni–Zn–Al ferrite spinel causes an improvement in magnetic parameters. Spectroscopic properties were discussed based on FTIR and Raman measurements and proved the purity and good crystallization of the samples.