A facile and green synthetic approach toward fabrication of alcea- and thyme-stabilized tio2 nanoparticles for photocatalytic applications

A facile and green synthetic approach was considered for the synthesis of stabilized titanium dioxide (TiO2) nanoparticles. Extracts of Alcea and Thyme plants were used to synthesis TiO2 nanoparticles for photocatalytic applications. Evaluation of the structural and phase formation via X-ray diffraction (XRD) indicated the formation of the anatase phase of TiO2 along with the rutile phase. A desired single phase of anatase was obtained upon heating the as-synthesized samples at 500 °C for 3 h. Using the information provided by the XRD analyzer and the Debye Scherer relationship, the average crystallite size was found to be around 6 and 10 nm for the samples synthesized using Alcea and Thyme plants, respectively. To determine the elemental analysis and chemical structure, the energy dispersive X-ray (EDX) analyzer and Fourier Transform Infrared (FTIR) spectroscopy were employed. Field emission scanning electron microscopy (FESEM) indicated batches of ultrafine agglomerated particles for both samples, which their sizes grew by the heating process. The UV–visible analysis of photocatalytic properties confirmed the priority of TiO2 nanoparticles prepared with Thyme extracts

Microwave sintering of Ni-Co doped barium strontium hexaferrite synthesized via sol-gel method

Microwave energy is highly efficient for heating and processing ceramic materials. Microwave sintering of doped barium strontium ceramics led to higher densification and the fine microstructure and improved magnetic properties. Effects of the substituted amount of Ni2+ and Co2+ on structure and magnetic properties of Ba0.5Sr0.5Fe12-xNixCoxO19 compounds have been systematically investigated by X-ray diffraction (XRD), high resolution scanning microscope (HR-SEM) and vibrating sample magnetometer (VSM). In our results, the suitable amount of Ni2+–Co2+ substitution slight decreased saturation magnetization. For Substitution of Ni-Co content of x≤0.4 the saturation magnetization varied from a range of 60.58 to 63.59 Am2/kg and while coercivity decreased from 805.37 to 280.28 Gauss respectively

A review on preparation techniques for synthesis of nanocrystalline soft magnetic ferrites and investigation on the effects of microstructure features on magnetic properties

Soft magnetic materials have been used in many applications, i.e., electrical and electronic industries, due to their desirable electromagnetic characteristics. The performance of these materials in bulk form, where the size of grains is in micrometer scale, is only limited to a few megahertz frequencies due to their higher conductivity and domain wall resonance. Synthesizing the ferrite particles in nanometer scales before compacting them for sintering would be one way to solve using these materials at higher frequencies. The properties of ferrite depend mainly on the technique and conditions of preparation, which, in turn, affect the cation distribution over the tetrahedral and octahedral sites. Thus, the aim of this study was to introduce some methods used for synthesizing nanocrystalline soft magnetic ferrites. Furthermore, the microstructure features, i.e., grain sizes and porosities, which are influenced by the types of method used for preparation, playing key role on the magnetic properties of the sample, are also highlighted

A comparative study of different concentrations of pure Zn powder effects on synthesis, structure, magnetic and microwave-absorbing properties in mechanically-alloyed Ni-Zn ferrite

In this study, a powder mixture of Zn, Fe2O3 and NiO was used to produce different compositions of Ni1-xZnxFe2O4 (x=0.36, 0.5 and 0.64) nanopowders. High-energy ball milling with a subsequent heat treatment method was carried out. The XRD results indicated that for the content of Zn, x=0.64 a single phase of Ni-Zn ferrite was produced after 30 h milling while for the contents of Zn, x=0.36 and 0.5, the desired ferrite was formed after sintering the 30 h-milled powders at 500 °C. The average crystallite size decreased with increase in the Zn content. A DC electrical resistivity of the Ni-Zn ferrite, however, decreased with increase in the Zn content, its value was much higher than those samples prepared by the conventional ceramic route by using ZnO instead of Zn. This is attributed to smaller grains size which were obtained by using Zn. The FT-IR results suggested two absorption bands for octahedral and tetrahedral sites in the range of 350-700 cm-1. The VSM results revealed that by increasing the Zn content from 0.36 to 0.5, a saturation magnetization reached its maximum value; afterwards, a decrease was observed for Zn with x=0.64. Finally, magnetic permeability and dielectric permittivity were studied by using vector network analyzer to explore microwave-absorbing properties in X-band frequency. The minimum reflection loss value obtained for Ni0.5Zn0.5Fe2O4 samples, about -34 dB at 9.7 GHz, making them the best candidates for high frequency applications

Magnetic carbonyl iron suspension with Ni-Zn ferrite additive and its magnetorheological properties

Ni-Zn ferrite nanoparticles were synthesized via a thermo-mechanical alloying route and adopted as an additive for micron-sized CI-based magnetorheological (MR) fluid. Structure, morphology and magnetic property of the nanoparticles were evaluated through X-ray diffraction pattern (XRD), vibration sample magnetometer (VSM) and transmission electron microscopy (TEM), respectively. The MR characteristics of two fluid systems with and without a nano-sized ferrite additive were studied and compared under different magnetic field strengths using a rotational rheometer. The MR fluid with Ni-Zn ferrite nanoparticles added exhibited remarkably higher yield behaviors, suggesting that the nano-sized ferrite and micron-sized CI particles were being oriented in magnetic field direction under applied field and with strengthened chain-like structure

Enhanced magnetorheology of soft magnetic carbonyl iron suspension with binary mixture of Ni-Zn ferrite and Fe3O4 nanoparticle additive

Fe3O4 and Ni0.5Zn0.5Fe2O4 nanoparticles were synthesized via precipitation and mechanical alloying, respectively, and assessed as a potential magnetorheogical (MR) additive. X-ray diffraction and transmission electron microscopy were employed to evaluate the phase formation and structural and morphological changes. Vibrating sample magnetometer (VSM) was used to measure magnetic characteristics of the samples. The MR characteristics of carbonyl iron (CI)-based and 1 wt.% (Ni0.5Zn0.5Fe2O4 + Fe3O4) CI-based suspensions were measured from a steady and rotational rheometry by applying magnetic field strengths ranging from 0 to 558.39 kA/m with 79.77-kA/m increments. The results indicated that the MR effect of the micron-sized, CI-based MR fluid significantly improved in the presence of nanoparticle additives, e.g., having higher-yield characteristics. Chain-like structure formed in the presence of nanoscale additives improved the MR performance and sedimentation stability of the CI particles

Synthesis, Characterization, and Cytotoxicity of Iron Oxide Nanoparticles

In order to study the response of human breast cancer cells' exposure to nanoparticle, iron oxide (α-Fe2O3) nanoparticles were synthesized by a simple low temperature combustion method using Fe(NO3)3·9H2O as raw material. X-ray diffraction studies confirmed that the resultant powders are pure α-Fe2O3. Transmission electron microscopy study revealed the spherical shape of the primary particles, and the size of the iron oxide nanoparticles is in the range of 19 nm. The magnetic hysteresis loops demonstrated that the sample exposed ferromagnetic behaviors with a relatively low coercivity. The cytotoxicity of α-Fe2O3 nanoparticle was also evaluated on human breast cancer cells to address the current deficient knowledge of cellular response to nanoparticle exposure

Outstanding supercapacitor performance of nd-mn co-doped perovskite lafeo3@nitrogen-doped graphene oxide nanocomposites

Perovskites have been significantly considered as promising materials for electrochemical energy storage in the recent years. Co-doping of Mn and Nd with hydrothermally synthesized LaFeO3 (LF) perovskite resulted in La0.8Nd0.2Fe0.8Mn0.2O3 (LNFM) with significantly higher specific capacitance of 158 F/g at 50 mV/s compared to non-doped and single doped LF samples. Subsequently, LNFM/nitrogen-doped graphene oxide (NGO) nanocomposite was prepared and investigated. It was found out that the introducing of NGO substantially enhances the specific capacitance of the nanocomposite up to 1060 F/g at 50 mV/s. Besides, the composite revealed outstanding capacity retention as 92.4% after 10000 continuous cycle (85.37% for the LNFM sample). In overall, the electrochemical behavior of the composite with 1:1 ratio of LNFM/NGO confirms its high potential as supercapacitor for energy storage applications