scholarly journals Zinc and cobalt nano ferrites and their potential applications in environmental sustainability

2020 ◽  
Author(s):  
Leena V. Hublikar ◽  
Sharanabasava V Ganachari ◽  
Jayachandra S. Yaradoddi ◽  
Aasim U. Mokashi

Abstract Fundamental research and industrially applied research, currently depend on magnetic oxide nanoparticles and ferromagnetic oxides due to their extensive applications for electronic, magnetic, optical sensor and absorptive activities. ferromagnetic substances mainly contain different type of Ferrite. Ferrite material constitutes, Iron oxide (Fe2O3) and divalent metal oxides of Transition metals like cobalt, nickel etc. The key objective of this paper is to study the impending applications of nano - ferrites doped with bivalent transition metals with their properties. Low-Temperature Self-Propagating combustion method was used to synthesize the particles. Synthesized Zinc and Cobalt Nano ferrites from the chemical co-precipitation method were found to be of 20 to 90 nm in average size, and comparative study of their properties using the results of Fourier-transform spectroscopy (FTIR) and X-ray powder diffraction (XRD). The Field Emission Scanning Electron Microscope (FESEM) confirms the conception of ferrite nanoparticles with a structure type cubic spinel. Further comparative Sensing studies showed that the sample displays variation in resistance when gases are passed over the surface, and the change in resistance is observed.

2021 ◽  
Vol 13 (5) ◽  
pp. 812-819
Author(s):  
Mohamed Helmi Hadj Alouane ◽  
Faheem Ahmed ◽  
Nermin Adel Hussein El Semary ◽  
Munirah F. Aldayel ◽  
Fatimah H. Alhaweti ◽  
...  

In this work, carbon-based nanomaterials including; carbon nanotubes (CNT) and graphene were combined with biofertilisers and tested their impact on germination of Hordeum vulgare. The interaction between nanomaterials and biofertilisers was analysed. Scanning electron microscopy (SEM) images revealed that the surface of algal cells was covered with carbon nanomaterials including graphene and CNTs. Raman studies showed the characteristic band of graphene, CNTs and Algal cells. The combination of carbon nanomaterials with biofertilizers resulted in significantly better growth than with nanomaterials individually. To prepare a more effective superfertiliser, zinc ferrites (ZnFe2O4) nanoparticles were added to the nanomaterials-biofertilisers combination. These zinc ferrites nanofertilisers had a size ranging from 8–12 nm and were prepared by co-precipitation method and used at two different doses. The results showed that the growth parameters were increased most significantly with addition of 0.25 ml of ZnFe2O4 nanoparticles. Increasing the dose caused a less increase in growth parameters. These results indicated that increase in growth parameters was dose-dependent. These results demonstrated a great promise for novel formulation of superfertiliser that significantly enhanced plant growth without pollution or excessive use of harmful chemicals for better food security and environmental sustainability.


2016 ◽  
Vol 875 ◽  
pp. 24-44
Author(s):  
Ming Guo Ma ◽  
Shan Liu ◽  
Lian Hua Fu

CaCO3 has six polymorphs such as vaterite, aragonite, calcite, amorphous, crystalline monohydrate, and hexahydrate CaCO3. CaCO3 is a typical biomineral that is abundant in both organisms and nature and has important industrial applications. Cellulose could be used as feedstocks for producing biofuels, bio-based chemicals, and high value-added bio-based materials. In the past, more attentions have been paid to the synthesis and applications of CaCO3 and cellulose/CaCO3 nanocomposites due to its relating properties such as mechanical strength, biocompatibility, and biodegradation, and bioactivity, and potential applications including biomedical, antibacterial, and water pretreatment fields as functional materials. A variety of synthesis methods such as the hydrothermal/solvothermal method, biomimetic mineralization method, microwave-assisted method, (co-) precipitation method, and sonochemistry method, were employed to the preparation of CaCO3 and cellulose/CaCO3 nanocomposites. In this chapter, the recent development of CaCO3 and cellulose/CaCO3 nanocomposites has been reviewed. The synthesis, characterization, and biomedical applications of CaCO3 and cellulose/CaCO3 nanocomposites are summarized. The future developments of CaCO3 and cellulose/CaCO3 nanocomposites are also suggested.


2020 ◽  
Vol 981 ◽  
pp. 59-65
Author(s):  
Muhammad Hafiz Mazwir ◽  
Bryan Andrew Balasan ◽  
Farah Hanani Zulkifli ◽  
Roslan Abd-Shukor

Effect of complex magnetic oxide Co0.5Ni0.5Fe2O4 (CNFO) nanoparticles addition in (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (Bi-2223) superconductor tapes was investigated. Ultrafine Bi-2223 powder precursor was prepared via co-precipitation method and was added with 0.01 – 0.05 wt.% Co0.5Ni0.5Fe2O4 nanoparticles during the final heating stage. The sample with 0.01 wt.% addition, Bi-2223(CNFO)0.01 was found to have the highest critical current density, Jc. This sample were then chosen to be fabricated into Ag-sheathed superconductor tapes using the powder-in-tube (PIT) method. The tapes were sintered for 50 and 100 h at 845 °C. The phase, microstructure and Jc of the samples were determined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and four point probe, respectively. Jc of Ag-sheathed Bi-2223(CNFO)0.01 tapes sintered for 100 h was 19830 A/cm2 at 30 K and 3970 A/cm2 at 77 K compared to tapes without addition which showed a much lower Jc(6370 A/cm2 at 30 K). This study showed that CNFO nanoparticles could act as an effective flux pinning centers to enhance the critical current density in the Bi-2223 superconductor.


2019 ◽  
Vol 967 ◽  
pp. 259-266 ◽  
Author(s):  
Muhammad Rizal Fahlepy ◽  
Yuyu Wahyuni ◽  
Muhamma Andhika ◽  
Arini Tiwow Vistarani ◽  
Subaer

This research is about nanoparticles hematite (NPH) synthesized and characterized from natural iron sands using co-precipitation method and its potential applications as extrinsic semiconductor materials type-N. The aims of this study is to determine the process parameters to obtain hematite of high purity degree and to observe its physical characteristics as an extrinsic semiconductor materials type-N. The iron sand was first separated by magnetic technique and then dissolved into HCl solution before conducting the precipitation process. Precipitation was done by dripping ammonium hydroxide (NH4OH). Precipitated powder was dried at 80°C for 2 hours, and then calcined at 500°C, 600°C 700°C for 2 hours respectively. The composition of iron sands, purity degree, hematite mineral grain size, and space group were analyzed by XRF, XRD, FTIR and SEM. The XRF analysis result of raw material, showed that dominant element and composition in the sample is Fe with purity degree is 90.51%. The XRD result before and after precipitation showed Fe3O4 and α-Fe2O3. Fe3O4 purity degree was obtained 85%, and α-Fe2O3 in NPH500, NPH600, NPH700 were 63%, 83%, and 76%, respectively. FTIR spectral showed crystalline hematite characteristics stong band of 472.07 to 559.62 cm-1. SEM image showed the morphology of agglomeration particulates, when the calcinaton temperature increases, the agglomeration will be seperated due to thermal energy. Based on the charaterization results it was found that the natural iron sand synthesized has the potential to be applied as an N-type extrinsic semiconductor material.


2014 ◽  
Vol 602-603 ◽  
pp. 97-100
Author(s):  
Bing Bing Fan ◽  
Ke Ke Guan ◽  
Hao Chen ◽  
Xiao Xuan Pian ◽  
Chen Yang Wang ◽  
...  

CaO(15%)-ZrO2nano-powders were prepared by microwave pyrolysis in a multi-model chamber at the temperature ranging from 650°C to 800°C, with the precursor processed at different reaction temperature from 0°C to 80°C by chemical co-precipitation method. XRD and SEM techniques were used to characterize the phase transition and micrograph of powders. It is found that the content of m-ZrO2phase decreased with the increasing of reaction temperature and pyrolysis temperature. The high dispersed and superfine nano-powders were obtained at the pyrolysis temperature of 750°C for 20 min at 80°C. And only cubic ZrO2phase were detected in CaO (15%)-ZrO2powders and the average size of the powders is about 41 nm.


2018 ◽  
Vol 55 (1B) ◽  
pp. 7 ◽  
Author(s):  
Dai Hai Nguyen

The objective of this study is to prepare biodegradable iron oxide nanoparticles with gelatin (GEL) for paclitaxel (PTX) delivery. In detail, Fe3O4 nanoparticles were prepared and then coated them with GEL (Fe3O4@GEL) conjugate by co–precipitation method. Furthermore, the formation of Fe3O4@GEL was demonstrated by Fourier transform infrared (FT–IR) and powder X–ray diffraction (XRD). The superparamagnetic property of Fe3O4@GEL was also showed by hysteresis loop analysis, the saturation magnetization reached 20.36 emu.g–1. In addition, size and morphology of Fe3O4@GEL nanoparticles were determined by transmission electron microscopy (TEM). The results indicated that Fe3O4@GEL nanoparticles were spherical shape with average diameter of 10 nm. Especially, PTX was effectively loaded into the coated magnetic nanoparticles, 86.7 ± 3.2 % for drug loading efficiency and slowly released up to 5 days. These results suggest that the potential applications of Fe3O4@GEL nanoparticles in the development of stable drug delivery systems for cancer therapy.


2021 ◽  
Vol 21 (4) ◽  
pp. 2576-2581
Author(s):  
N. T. T. Thao ◽  
D. H. Nguyen ◽  
Pham The Kien ◽  
Thanh-Tung Duong ◽  
Nguyen Thi Kim Lien ◽  
...  

Magnetic magnetite (Fe3O4) nanoparticles with average sizes of 5.11, 10.53, and 14.76 nm were synthesized by the chemical co-precipitation method. The surface area of Fe3O4 nanoparticles (average size of 5.11 nm) had the largest value of 167 m2/g. The adsorption capacity for removing arsenic (As(V)) from water at 3 ppm concentration was investigated by atomic absorption spectroscopy. Results showed that the As(V) adsorption capacity of Fe3O4 was dependent on particle size. The maximum absorption efficiency (Hmax) reached 99.02%, the equilibrium time was 30 min; the maximum Langmuir isotherm adsorption capacity was 14.46 mg/g with Fe3O4 nanoparticle an average size of 5 nm. The results indicate that reducing the size of Fe3O4 nanoparticles is a promised way for As(V) ion removal from water and wastewater treatment.


2016 ◽  
Vol 16 (4) ◽  
pp. 3547-3556 ◽  
Author(s):  
Errui Yang ◽  
Guangshe Li ◽  
Yunlong Zheng ◽  
Liping Li

Selective synthesis of specific phased nanomaterials via a green route is a promising yet challenging task. In the present work, the hexagonal and monoclinic phases of BiPO4:Ln3+ (Ln = Sm, Eu, Tb, Dy) were prepared via room temperature co-precipitation method. For adjusting the phase of the products, the prepared mediums selected were the most common solvents, i.e., water and ethanol. It was very important that the prepared mediums could be easily recycled and reused by evaporating the filtrate. The formation mechanisms of hexagonal in water and monoclinic in ethanol were investigated. Interestingly, the growth behaviors of these phases were quite distinct and thus gave rise to distinct morphology and particle size. The hexagonal phase possesses a rod-like morphology with diameters of 50–160 nm and lengths of 65–400 nm while the monoclinic phase consists of almost entirely irregular nanoparticles. Also, it was found that the bending and stretching vibrations of O–H and PO4 tetrahedra were quite different for the products prepared in water and ethanol. Moreover, it was found that the luminescence properties, including emission intensity, lifetime, quantum efficiency, and color, could be readily tailored through controlling the phase structures and microstructures. The results showed that the monoclinic phase exhibited superior luminescent performance to the hexagonal phase. The methodologies reported in this work were fundamentally important, which could be easily extended to large-scale synthesis of other phased nanomaterials for potential applications as electroluminescent devices, optical integrated circuits, or biomarkers.


In–doped ZnS nanoparticles are synthesized via chemical co-precipitation method using different precursor solutions of zinc acetate (source of Zn2+ ions), sodium sulphide (source of S2- ions), indium sulphate (source of dopant In3+ ions), ammonium hydroxide (works as a complexing agent) and EDTA (as a capping agent). The effect of different concentrations of Indium (0%, 1%, 3%, and 5%) on the structure, morphology, and elemental composition properties of nanoparticles have been studied using different characterization techniques. XRD study shows the formation of cubic structure in the synthesized nanoparticles. The average size of nanoparticles calculated using Debye - Scherrer’s equation is in the range of 5.7–2.4 nm. It has been observed that the size of ZnS nanoparticles decrease with an increase in Indium concentration. SEM micrographs have explored the surface feature of the nanoparticles. It clearly shown that the morphology of spherical nanoparticles is changing with In concentration. The elemental identification and mapping has indicated the homogeneous distribution of Zinc, Sulfur and Indium content in synthesized nanoparticles. FT–IR spectra have recognized the existance of characteristics absorption peaks for In-doped ZnS


Author(s):  
Sanjay B. Nagdeote

The Sr0.5Ba0.5Nb2O6 (SBN-50) is Synthesis by coprecipitation method in nanoscale. TG/DTA shows the reaction and tetragonal phase formation occur at low temperatures, due to which the good homogeneity and morphology of the particles is observed. The average size of the particles was found to be ~ 45 nm. The lattice parameters is found very close to the reported values of single crystals despite method of synthesis and size of the particles. A reflectance spectrum in UV and visible regions shows less reflectance for 337nm and 519nm respectively.


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