Crystallite Size In Range Research Articles

Effect of charge-discharge with higher capacitance performance of Ni-substituted CoFe2O4 magnetic nanoparticles for energy storage

In this work, we synthesized NixCo1-xFe2O4 (0 ≤ x ≤ 0.8) magnetic nanoparticles (MNPs) by using ultrasonication-assisted reverse chemical co-precipitation method. The X-ray diffraction (XRD) patterns confirm the single-phase with mixed spinel structure of the NixCo1-xFe2O4 (0 ≤ x ≤ 0.8) MNPs with the crystallite size range between 12 nm - 17 nm. The molecular dynamics and oleic acid coated Ni-substituted CoFe2O4 magnetic nanoparticles were confirmed by FTIR measurements. The surface composition of NixCo1-xFe2O4 (0 ≤ x ≤ 0.8) MNPs (Ni, Co, Fe and O) and their oxidation states were estimated using X-ray photoelectron spectroscopy. The NixCo1-xFe2O4 (0 ≤ x ≤ 0.8) MNPs are spherical in shape and polycrystalline in nature, confirmed by FESEM and HRTEM measurements. The Ni-substituted CoFe2O4 MNPs with higher zeta potential (ζ) from −24 mV to -41 mV with an increase in Ni concentration, signifies the stable colloidal stability due to the electrostatic repulsion between MNPs. The DC magnetization (M-vs-H) measurements reveal the ferrimagnetic behavior of NixCo1-xFe2O4 (0 ≤ x ≤ 0.8) MNPs, which suppress the saturation magnetization (MS) from 48.6 emu/g to 5.3 emu/g with the enhanced coercivity (HC) from 335 Oe to 1700 Oe with the substitution of Ni2+ ions is in corroboration with electron paramagnetic resonance (EPR) measurements. The enhanced EPR resonance field (Hres = 2335 Oe - 3261 Oe) with the substitution of Ni2+ ions is attributed to the generation of oxygen vacancies and defects, which are predominant in Ni0.8Co0.2Fe2O4, resulting in significantly enhanced electrochemical performance. Therefore, the three-electrode system was utilized to investigate the electrochemical properties of NixCo1-xFe2O4 (0 ≤ x ≤ 0.8) MNPs. The Ni-substituted CoFe2O4 MNPs have demonstrated significantly enhanced capacity retention of 77 % even after 5000 cycles in 1 M H2SO4 electrolyte solution. NixCo1-xFe2O4 (0 ≤ x ≤ 0.8) MNPs exhibit an excellent specific capacity (Cs) of 794.5 F/g at a current density of 1 A/g, signifies the rate of redox reaction at surface electrolyte interface (SEI) is greatly influenced by the surface to volume ratio. Thus, with the enhancement of Ni2+ ions, redox reaction kinetics might become more efficient resulting in the enhanced charge storage capacity.

Abutilon indicum-mediated green synthesis of NiO and ZnO nanoparticles: Spectral profiling and anticancer potential against human cervical cancer for public health progression

BackgroundIntegrating nanomedicines for targeted cancer treatment and pursuing medicinally valuable components from nature are crucial for sustainable, potent alternatives to synthetic drugs in combating fatal diseases like cancer. Hence, a green synthesis of nickel oxide (NiO NPs) and zinc oxide nanoparticles (ZnO NPs) has been carried out by using the leaf extract of medicinally important plant Abutilonindicum. This sustainable approach to medical developments not only reduces the environmental effect of standard synthesis methods and offers new options for novel cancer therapeutics, but it also advances public health by using natural resources in a sustainable manner. MethodsThe synthesized nanoparticles were characterized by employing spectro-analytical techniques like UV–vis, FT-IR, SEM and powder XRD. Synthesized nanparticles were evaluated in the human cervical cancer cells (HeLa). ResultsNi-O stretching vibrations were observed at 402 cm−1, whereas that of Zn-O stretching was observed at 409 cm−1in the FT-IR spectrum, confirming the formation of nanoparticles. The XRD pattern revealed the crystallite size range of 1.35–2.84 nm for NiO NPs and 7.71–56.80 nm for ZnO NPs. The morphology of the nanoparticles, as indicated by the SEM images, was rod-like for NiO NPs and rock-shaped for ZnO NPs. Further, the cancer cell growth inhibition activity of the nanoparticles was examined by MTT assay against human cervical cancer cells (HeLa) proliferation and compared with cisplatin. MTT assay elucidated the significant anticancer efficacy of the synthesized nanoparticles, showcasing low IC50 values of 29±0.5 µg/ml for NiO NPs and 32±0.7 µg/ml for ZnO NPs. Furthermore, the anticancer activity of the NiO NPs was investigated using the Trypan blue dye exclusion technique, emphasizing the pronounced cytotoxic impact of NiO NPs on cancer cell viability. The outcomes underscore the notable anticancer properties of plant extract mediated metal nanoparticles as promising contenders for advancing cancer treatment modalities.

Comparative study on structural, morphological, and optical properties of MS/Fe3O4 nanocomposites and M-doped Fe3O4 nanopowders (M = Mn, Zn)

In the present work, the un-doped, M-doped magnetite (Fe3O4); (M = Mn, Zn), and MS/Fe3O4 composite nanopowders with a cubic spinel-type structure and average crystallite size range from 8.30 to 12.33 nm were synthesized by co-precipitation method. The FESEM images revealed the shape of particles are spherical with a grain size in the range of 33.44–49.77 nm. Through the analysis of reflectance data using Tauc’s model, the direct band gap energies of 2.98 eV, 2.93 eV, 3.01 eV, 2.85 eV, and 2.95 eV were determined for Un-doped Fe3O4, Mn-doped Fe3O4, Zn-doped Fe3O4, MnS/Fe3O4 composite, and ZnS/Fe3O4 composite NPs respectively. The parameters such as extinction coefficient and refractive index of the nanoparticles were computed by the Kramers–Kronig (K–K) method. Non-linear optical (NLO) parameters were computed from DRS data using the Wemple–Di-Domenico (WDD) model. The calculated third-order NLO susceptibility χ(3)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }^{(3)}$$\\end{document} and also electrical susceptibility χe\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }_{\\left(e\\right)}$$\\end{document} represented the maximum value for MnS/Fe3O4 composite NPs compared to the other samples. Considering the advanced optical parameters of MS/Fe3O4 composite samples, these particles can be suitable candidates for non-linear optical applications.

Synthesis of nano calcium silicates from waste calcite and aragonite phases for efficient adsorptive removal of industrial organic pollutants

The present study focuses on the adsorption efficacy of solid-state synthesized calcium silicate for removing congo red dye. Three different sources were used as calcium precursors; one was calcium carbonate, and the other two were natural waste sources, aragonite (P. globosa) and calcite (Eggshells). Structural analysis and functional groups of the samples were carried out by X-ray diffractometer (XRD), and a Fourier Transform Infrared Spectrometer (FTIR). Various well-known models/equations models such as the Liner Straight Line method of Scherrer’s equation (LSLMSE), Sahadat-Scherrer Model (SSM), Monshi-Scherrer model (MSM), Williamson-Hall model (WHM), Size-Strain plot method (SSP), and Halder-Wagner Model (HWM) were applied to compute the crystallite size of the synthesized calcium silicates; the estimated crystallite size range was 8–77 nm. The adsorption efficacy of the synthesized E-CaSiO3, S-CaSiO3, and C-CaSiO3 was assessed under various provisos for eradicating Congo red dye from wastewater. Computed results revealed that the dye removal percentages were approximately 100 % at 120 min and 200 rpm for 0.2 g E-CaSiO3. The point of zero charge evaluation showed that the pH of the adsorbents during maximum dye removal was 7 and was less than the value of pHpzc. Thermodynamics studies confirmed that the adsorption process was spontaneous. The method of adsorption of dye by the adsorbent was more clearly comprehended by Langmuir, Freundlich, and Temkin adsorption isotherm. 151.28 mg/g was the maximum adsorption capacity for S- CaSiO3 depending on the Langmuir isotherm model’s linear form (R2 = 0.924).

Green biosynthesis of Ag2O nanoparticles by aqueous leaves extract of Thymus capitatus (Lamiaceae): effect of silver nitrate weight in optical and their biological activity

In this study, green synthesis of silver oxide nanoparticles (Ag2O NPs) was achieved by bio-reduction of AgNO3 using Thymus Capitatus leaves extract. The effect of silver precursor contraction (0.1–1 g, AgNO3) was studied. X-ray diffraction confirmed the crystalline nature of Ag/Ag2O NPs with a crystallite size range from 18 to 24 nm. SEM showed that the green synthesizing silver oxide nanoparticles having in general as cubical shape. The obtained Ag2O NPs exhibit absorption at 273 nm with a direct bandgap ranging from 3.87 to 4.02 eV and an indirect bandgap of 2.99–3.44 eV, according to Uv-visible spectra. FTIR analysis exhibit a two weak peak at 517 and 458 cm−1 attributed to silver oxide-NPs vibration, confirming the nanoparticles formation. Among the examined extracts, Ag2O NPs with 1 g weight of AgNO3 showed the highest antioxidant activity with value of 3.42, 18.98 and 18.97 mg/mL for DPPH, FRAP and TAC tests respectively.

Dielectric and magnetic response of Cu-Co-Sm ferrite impregnated with graphene nanoplatelets for high-frequency device applications

This work studied a composite of graphene nanoplatelets (GNPs) impregnated copper-cobalt-samarium ferrites Cu0.5Co0.5Fe1.97Sm0.03O4/GNPs synthesized via sol-gel auto-combustion route. The structural, electrical, dielectric, and optical properties of the as-prepared composites were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), EDX, I-V characteristics, impedance measurement, raman spectroscopy, scanning electron microscopy (SEM), vibrating sample magnetometry (VSM) analysis, and UV–visible spectroscopy. XRD confirmed that the spinel ferrites had a crystalline single-phase FCC structure with the lattice constant of around 8.33 Å, and the crystallite size range from 54.10 nm to 51.85 nm. SEM analysis confirmed the homogenous dispersion of spinel ferrites in graphene sheets, and EDX confirmed the presence of all elements in ferrite composites with GNPs. Furthermore, the spinel matrix was confirmed by the Raman and UV-visible analysis. A minimum particle size of 21.73 nm was determined using TEM, and the minimum value of activation energy (0.01 eV) was obtained from IV characteristics for ferrite composite with 2.5% GNPs. Further, our ferrite composites with GNPs demonstrated improved electroconductive properties, with conductivity ranging from 5.88×10−8S/cm to 1.04×10−6S/cm at 673 K. The real & imaginary part of permittivity, dielectric constant (ε’), and impedance (Z) were also improved with the addition of GNPs. At low frequencies, a permeability loss value of 0.81 was obtained for the ferrite composite with 5% GNPs. VSM analysis confirmed that the saturation magnetization decreased in ferrite composites with graphene nanoplatelets. The minimum value of skin depth of 1.03 mm was observed at 1.25 % GNPs. Our ferrite composites with GNPs exhibited minimal eddy current at high frequencies, making them promising candidates for high-frequency device applications.

Sustainable synthesis of nano CuO from electronic waste (E-waste) cable: Evaluation of crystallite size via Scherrer equation, Williamson-Hall plot, Halder- Wagner model, Monshi-Scherrer model, size-strain plot

Electronic waste (E-waste) is going to be one of the most hazardous materials for a sustainable environment in the technologically advanced era. In this research, waste electric cable was taken for efficient production of CuO using an easy and simple way. The synthesized product, CuO, was confirmed by the X-ray diffraction (XRD) data, and optical bandgap energy was also estimated. Various crystallographic parameters such as lattice parameters, the volume of unit cell, relative intensity, and preference growth were estimated from XRD data. Scherrer equation, Williamson-Hall plot (Uniform Deformation Model (UDM), Uniform Stress Deformation Model (USDM), Uniform Deformation Energy Density Model (UDEDM)), Halder-Wagner Model, Monshi-Scherrer Model, and Size- Strain plot were employed to calculate crystallite size and few models also exerted stress, strain and energy density. The estimated range of crystallite size was from 7 to 14 nm, strain from 5 × 10−4 to 1.5 × 10−3, stress of 1.0487 GPa, and energy density of 8.12 × 10−4 GPa using different model equations. The preference growth indicated that the (2 0 0) plane is the preferred direction for the synthesized conditions. FTIR spectrum and optical bandgap energy were also estimated for the synthesized products. The Rietveld refinement indicated that the synthesized product contained 99.524 % tenorite (CuO), and 0.476 % Cu2O phases.

Europium decorated hierarchical TiO2 heterojunction nanostructure with enhanced UV light photocatalytic activity for degradation of toxic industrial effluent

Europium (Eu) doped cetyltrimethylammonium bromide (CTAB) surfactant assisted hierarchical TiO2 heterojunction nanostructure was synthesized by solvothermal method with ethanol as a solvent. The prepared nanostructure was subjected to various characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive spectrum (EDS) and Ultraviolet – diffuse reflectance spectroscopy (UV -DRS). The anatase phase of titania with its highly crystalline nature is confirmed by the XRD pattern. Crystallite sizes range from 4 to 10 nm according to XRD peak estimates. TEM and HRTEM studies are used to examine the prepared samples particle size and morphology. The elemental composition of the Europium (Eu) doped CTAB assisted TiO2 heterojunction nanostructure along with their corresponding band gap was estimated by EDS and UV-DRS studies respectively. The bandgap of the samples evaluated by UV–Visible spectroscopy are 3.40, 3.41 and 3.43 eV. The photocatalytic test was conducted in the presence of UV light and the amount of Congo red dye degradation increased with the time in the presence of the catalyst. After 75 min, it was discovered that the photocatalytic degradation efficiency was 97%. The photocatalytic effect depends heavily on the dispersion of the dopants.

ZnO and La-doped ZnO films by USP method and their characterizations for ultraviolet photodetectors and photocatalysis applications

In this study, ZnO, Zn1-xLaxO [2, 5, 10, 15 at.%] thin films were grown on glass substrates using the spray-pyrolysis technique, to investigate the effect of doping on the structural, morphological, thermoelectric and optical properties of the layers, Also the samples were tested as UV photodetectors and photocatalyst for MB degradation. Firstly, diffraction patterns showed a hexagonal structure, with preferential grain orientation along the (002) direction, for pure ZnO and 2%La_ZnO layers, and at 5 at.% the preferential orientation changes, and crystallite sizes range from 10 nm to 19 nm. However, SEM images reveal that the ZnO and 2%La_ZnO layers are nanorods distributed over their surfaces, and the other 5%LZO, 10%LZO and 15%LZO layers characterized by nanocrystals were hexagonal prisms. The UV–visible analysis of the prepared layers shows high transparency (80–90%) in the visible range, with a constant optical gap of 3.26 eV. Thermoelectric measurements show that the ZnO and LZO layers are non-degenerate, with a maximum charge concentration of 9.18 × 1017 cm−3 for the 15% LZO films. The thin films show an ability for UV detection, while the 5%La_ZnO layers remain the best for UV photodetection with a good sensitivity (5.07) compared with the other layers. In terms of methyl blue degradation, the 5%La_ZnO thin films had a better degradation of 95%.

Effect of ZnO on the Structural and Magnetodielectric Properties of MgFe2O4 Nanocomposite Prepared by Sol-Gel Method

Zinc oxide doped magnesium ferrite (Mg1-xZnxFe2O4) nanocomposite was synthesized using sol-gel method and demonstrated to have a cubic spinel structure, with a range of crystallite sizes (19-40 nm) and lattice constants (8.432-8.399 Å). The material was found to have two prominent vibrational modes for tetrahedral (446 cm–1) and octahedral (584 cm–1). The dielectric constant was higher at low frequencies and decreased at higher frequencies, while the saturation magnetization decreased (16 to 6 emu/g) gradually with an increase in Zn2+, likely due to the presence of non-magnetic Zn2+. The magneto-dielectric constant was found to increase with the magnetic field for MgFe2O4 and up to a magnetic field of 2000 Oe for the zinc magnesium nanocomposites, after which it decreased for higher magnetic fields. A positive and negative change in magneto-capacitance as a function of the magnetic field was also observed. The antibacterial activity suggests that the substitution of Zn2+ into magnesium ferrite can be an effective method for improving antibacterial activity, with the potential to damage the bacterial membrane and other components through positively charged ions and ROS generated by nanoparticles. Potential uses for this synthetic material include magneto-optical recording and magnetic biosensors.

Bimetallic CuO−ZnO Hybrid Nanocomposite Materials for Efficient Remediation of Environmental Pollutants

AbstractPure CuO and 2‐Dimentional CuO−ZnO nanocomposites (NCs) were effectively prepared by an ultrasound‐assisted probe sonication route for different ratios of CuO and ZnO, and the multifunctional properties were investigated by the application of the advanced methods. XRD (X‐ray diffraction) patterns revealed a crystallite size (D) range of 25 to 31 nm for pure CuO and CuO−ZnO NCs. According to calculations, the energy band gap value (Eg) for the NCs is between 2.15 and 2.48 eV. Under UV light irradiation, the photocatalytic degradation of pure CuO and CuO−ZnO NCs on Direct Green (DG) and Fast Blue (FB) dyes was assessed. 60 mg of the catalyst was added to 20 ppm solutions of DG and FB dye. The stock solution of the dyes was prepared 10, 15, 20 and 25 ppm of 250 ml dye solution. Electrochemical analysis using cyclic voltammetry revealed improved redox potential output in the electrode crafted with graphite powder in 0.1 N HCl electrolyte solution. These NCs were used because of their capacity to detect an extremely dangerous chemical like arsenic. The constructed electrode‘s lowest limit of detection was determined to be 110–3 mol/L. In general, vertical linearity was seen in all of the prepared nano‐electrodes, especially above 150 ohms with real axis for pure CuO but beyond 100 ohms for doped electrodes. Based on our study, we conclude that the CuO and ZnO NCs, containing 10 % of ZnO, were the most effective photocatalyst for DG and FB dyes and electrochemical sensor for Arsenic.

Enhanced Photocatalytic Applications of Chitosan Encapsulated Silver Sulphide Quantum Dots

This study explores the synthesis, properties, and applications of chitosan-encapsulated silver sulphide (Ag2S) quantum dots (QDs) for biological applications. The investigation focuses on the fluctuations in the physico-chemical characteristics of chitosan Ag2S QDs, which can be carefully studied due to their environmental activity. X-ray diffraction (XRD) measurements reveal that chitosan-coated Ag2S QDs exhibit higher-intensity peaks. The XRD analysis reports a range of crystallite sizes, with a minimum size of 8 nm and a maximum size of 12 nm. Fourier-transform infrared (FTIR) spectroscopy confirms the presence of chitosan through the detection of functional group peaks. High-resolution transmission electron microscopy (HRTEM) studies indicate that the size of the artificial quantum dots is 6 nm. Energy-dispersive X-ray spectroscopy (EDX) verifies the composition of chitosan-encapsulated Ag2S QDs. Moreover, the chitosan Ag2S quantum dots demonstrate exceptional photocatalytic activity, as evidenced by the degradation of 92% of methylene blue dye within one hour. This research provides valuable insights into the synthesis, properties, and potential applications of chitosan-encapsulated Ag2S quantum dots in diverse fields.

Surface hardness of pristine and laser-treated zinc as a function of indentation load and its correlation with crystallite size valued by Williamson-Hall analysis, size-strain plot, Halder-Wagner and Wagner-Aqua models

To get a range of crystallite size, 5 N pure polycrystalline zinc specimens were shined with 50–100 Nd:YAG laser shots. Williamson-Hall, Size-Strain Plot, Halder-Wagner, and Wagner-Aqua models were employed to evaluate the crystallite size and lattice strain of pristine and laser-treated specimens. Surface hardness of the specimens were measured under 0.2 and 0.3 kgf indentation loads for 10 s. In each case, the surface hardness followed inverse Hall – Petch Relation. For a fixed number of laser shots, the surface hardness was greater for 0.2 kgf indentation load than that for 0.3 kgf. The surface hardness of pristine zinc specimen increased on treatment with 50 laser shots. With further rise in laser shots up to 80, the surface hardness progressively decreased close to that of pristine specimen. Later, it again increased for 90 laser shots and then slightly decreased for 100 laser shots.

The Effect of PbS Colloidal Quantum Dots with CdS and ZnS Coating on Photovoltaic Properties

In this research, we used the co-precipitation method to fabricate lead sulfide colloidal quantum dots (PbS CQDs) for photovoltaic cells. PbS CQDs were deposited uniformly on a titanium dioxide electrode by the dip-coating method. Photoelectrodes were prepared by coating layers using the successive ionic layer adsorption and reaction (SILAR) method. A solar simulation was used to investigate the photovoltaic properties of photoelectrodes under one sun illumination (100 mW/cm2) at room temperature (AM 1.5 G). The photovoltaic measurements demonstrated that TiO2/PbS CQDs with CdS and ZnS coating electrodes had a maximum power conversion efficiency (PCE) of 1.01 %. The crystallite size of PbS CQDs with different coating layers was analyzed using X-ray diffraction (XRD), and the crystallite size range was 6-7 nm. The existence of PbS CQDs and coating layers on the TiO2 electrodes was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). UV-visible spectroscopy was used to obtain the optical properties of the photoelectrodes. The optical band gap was 0.72-0.75 eV.

The Effect of Electrodeposition Current and Electrolyte Composition on Electrodeposition of Fe-Ni Alloys

This research was conducted to determine the effect of solution variations, electrical current, thickness, weight, metal composition, and the characteristics of the Fe-Ni alloy synthesized using the electrodeposition method. The instruments used in this study were atomic absorption spectroscopy (AAS) to determine the metal composition in the deposit, X-ray diffraction to determine the diffraction patterns, and scanning electron microscopy (SEM) to observe morphology and energy dispersive X-ray spectroscopy for elemental analysis. The SEM micrographs obtained showed that morphology of the Fe-Ni alloy was in the form of refined grains. The percentage of Fe in the deposit decreases with the increase in the used current. The AAS data also showed that a high Ni composition in solution will affect the atomic percent of each metal in the deposit. The formation of the alloy was confirmed by diffraction peaks at 2θ of 44°, 53°, and 76° that associated with reflection planes of the face centered cubic structure of Fe-Ni with the crystallite size range from 5 nm to 35 nm.

Photocatalytic Decomposition of an Azo Dye Using Transition-Metal-Doped Tungsten and Molybdenum Carbides.

The preparation, characterization, and photocatalytic application of tungsten or molybdenum carbides (Ni-WC, 1, Co-WC, 2, Ni-MoC, 3, Co-MoC, 4, NiCo-WC, 5, NiCo-MoC, 6, NiFe-WC, 7, and NiFe-MoC, 8) doped with transition metals (Fe, Co, and Ni) are reported. These transition-metal carbide (TMC) particles show that the submicrometer globular particles agglomerated to form larger particles, with smaller crystallites present on the surface of the large particles. These crystallite sizes range between 4 and 34 nm (as calculated from X-ray diffraction data) depending on the metal dopant and type of carbide. Oxidation of the metal carbides is evident from the two sets of photoelectron lines present in the X-ray photoelectron spectroscopy (XPS) of the W 4f area. The Mo 3d spectra reveal four sets of photoelectron lines associated with oxidized MoO2 and MoO3 as well as Mo2+ and Mo3+ associated with MoC1–x. The XPS of the dopant metals Ni, Co, and Fe also show partial oxidation. The photocatalytic decomposition of Congo red (an azo dye) is used as a model reaction to determine the photocatalytic activities of the transition-metal carbides, which is related to the TMCs’ optical band gap energies.

Experimental investigation on ferrofluid properties of Cd doped Co-Zn ferrites

"Cadmium substituted Co-Zn ferrites 𝐶𝑜0.5𝑍𝑛0.5𝐶𝑑𝑥𝐹𝑒(2−𝑥)𝑂4 (𝑥=0.0, 0.1, 0.2, 0.4, and 0.5) were fabricated by using the Co-precipitation method. The molecular composition and prepared samples of cubic spinel structureswas characterized using X-ray diffraction peak (XRD). X-ray diffraction patterns obtained the most intensive peak at (311) crystallographic planes for x=0.5. Williamson-Hall (W-H) relation was associated with XRD data to determine the crystallite sizes range from 25.356 nm to 35.632 nm and strain value brought into being 0.0024 to 0.0021. Tetrahedral and octahedral sites of hoping length were found to diminish from 3.6707Å-3.6332Å and 2.9967Å-2.9662Å respectively due to the addition of Cd ion concentration. TEM analysis reveals the presence of spherical shape nanoparticles with agglomeration for the prepared samples. It could be referenced based on the investigation of results for molecule size by two XRD and TEM strategies which demonstrate the development of nanomaterials and doping of cobalt ferrites. TEM results are well agreed with the XRD diffraction pattern in crystallite size by using Scherrer’s formula. Fourier Transform Infrared Spectroscopy (FTIR) spectra analysis were carried out on synthesized ferrite samples and observed v1 and v2 strong absorption band in the range 400-4000 cm-1 be the possession to tetrahedral (A) and octahedral (B) sites. In FTIR, the increase of Cd2+ ion in Co-Zn ferrites leads to diminishing peak values towards lower wavenumbers. It is feasible to tune the magnetic characteristics of cobalt ferrite as a potential material for diverse technological applications by substituting Zn2+ and Cd2+ for cobalt magnetic ions."

Influence of Zn in the CdS Crystal Lattice and Its Impact over the Catalytic Activity in the H2 Production

Solid solutions ZnxCd1−xS were compared by coprecipitation and sonochemistry methods, where x = 0.2 . This rate is the one that presents the best photocatalytic activity and the best performance for the production of hydrogen from a water source, according to our previous results. The influence of the synthesis method on the morphology and its electronic properties of the CdS and Zn0.2Cd0.8S systems was investigated, as well as the effect of the incorporation of Zn in the crystal lattice and its effect on the production of hydrogen from the division of water. X-ray diffraction characterization confirmed the formation of a solid solution corresponding to a face-centered cubic crystalline phase with preferential growth of (111), (220), and (311) planes and hierarchical morphology according to SEM and TEM microscopy, formed by aggregated nanoparticles of ZnxCd1−xS compound. The crystallite size decreased with the Zn incorporation in the crystal lattice from 8.61 nm by a coprecipitation method to 4.37 nm when the synthesis was assisted with sonochemistry, and the crystallite sizes range from 7.92 nm to 3.80 nm for the case of CdS pure. Other characterization techniques were also used, such as photoluminescence (PL), Raman microscopy, and N2 adsorption and desorption. The PL results show tunability of band edge emission as a function of zinc concentration in the Zn0.2Cd0.8S nanoparticles. For the water splitting to hydrogen production, the separation of the charge carriers promoted by the incorporation of Zn in addition to the shallow trap emissions generated defects in the catalyst structure; such processes are important factors found which increased with the sonochemical method, as well as the potential matched positions.

Enhanced photocatalytic efficiency of MWCNT/NiFe2O4 nanocomposites

Here, we observed NiFe 2 O 4 nanoparticle and multi-walled carbon nanotubes MWCNT/NiFe 2 O 4 hybrid nanocomposite for the photocatalytic properties to degrade methylene blue in UV as well as Visible light irradiation. The materials were prepared via hydrothermal method using purified MWCNT. X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Transmission electron microscopy (TEM) study confirms the formation of nanocomposite with crystallite size range of 9–11 nm. The key result of this work is the high performance of the MWCNT/NiFe 2 O 4 nanocomposite, which yielded the highest observed photocatalytic activity compared to NiFe 2 O 4 nanoparticle. This significant enhancement in photocatalytic activity under both UV and visible light can be ascribed to the interfacial charge transfer between NiFe 2 O 4 and MWCNT which inhibits the electron-hole recombination. The study also shows that higher loaded MWCNT in the nanocomposite shows higher Photocatalytic efficiency and larger kinetic rate constant. • Synthesis of MWCNT/NiFe 2 O 4 nanocomposites using hydrothermal co-precipitation method. • PL spectrum also suggesting the lower recombination of electron and hole in case of higher loaded MWCNT. • Fast photo degradation of Methylene blue by using MWCNT/NiFe 2 O 4 nanocomposites both in UV as well as Visible light. • Reusability of MWCNT/NiFe 2 O 4 photocatalyst due to the magnetic effect of NiFe 2 O 4.

Phase diagram for nanocrystals

ABSTRACT The new form of the phase diagram is proposed for nanocrystals. This island diagram shows the regions of the calcination temperature required to obtain the nanocrystals of given range of crystallite size. This explains why the temperature-induced phase transitions are not possible in some crystals. However, the change of crystallite size can induce the phase transition.