Field Emission Scanning Electron Microscopy Images Research Articles

Ferromagnetism behavior of Ni-doped Fe3O4 thin films synthesized by the SILAR technique

In this article, Ni-doped Fe3O4 thin films were synthesized by using the SILAR technique. The films were characterized through X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Raman, Photoluminescence and UV–Vis analysis. The XRD spectrum confirms the spinal structure of undoped and Ni-doped Fe3O4 thin films. The FESEM images show that Ni-doping has changed the morphology of thin films from a granular to a Spiky structure. The EDAX and XPS spectra show Fe, Ni and O elements are present in 1%Ni-doped Fe3O4 thin film. The vibrating sample magnetometer (VSM) studies showed ferromagnetism in undoped and Ni-doped Fe3O4 thin films. The ferromagnetism behavior of Ni-doped Fe3O4 thin films increases with the increase in Ni ion concentration.

A novel bifunctional electrochemical nanosensor for simultaneous detection of glucose and insulin based on NiO/Co3O4@CuAl LDH-MWCNT nanocomposite-modified carbon paste electrode

The appropriate development of electrocatalytic nanomaterials is a significant step for constructing high-quality non-enzymatic electrochemical sensors. In this work, we presented effective copper aluminum layered double hydroxide (CuAl LDH)-based nanoparticles with two consecutive optimization steps through nickel oxide/cobalt oxide (NiO/Co3O4) merging and subsequent assembly with multi-walled carbon nanotubes (MWCNT). The obtained nanostructures were characterized by using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction pattern (XRD), and field emission scanning electron microscope images (FE-SEM). The synthesized nanomaterials were used as a carbon paste electrode (CPE) material for simultaneous dual-signal evaluation of glucose and insulin. The response of the modified electrode was investigated by some electrochemical approaches, including cyclic voltammetry (CV), electrical impedance (EI), differential pulse voltammetry (DPV), and amperometric titration. The NiO/Co3O4 CuAl LDH@MWCNT electrode displayed multi-functional properties through two well-defined separated peaks toward glucose and insulin detection with a linear range of 0.01–26.5 mM and 0.02–70.0 nM, respectively. The detection limit values were obtained as 2.8 µM for glucose and 17.3 pM for insulin. The sensor showed good tolerance to common interfering agents, excellent sensitivity, and appropriate stability during 30 days of dry storage at room temperature. This sensor was also used for the quantification of glucose and insulin in human serum samples, obtaining the recovery rate of 101.0 %-103.7 % and 98.0 %-106.0 %, respectively, with all the RSD values below 3.0 %. This study represented an efficient simultaneous sensing platform for glucose and insulin detection, which warrants its operational application in clinical samples.

Evolution of fractal characteristics in shales with increasing thermal maturity: Evidence from neutron scattering, N2 physisorption, and FE-SEM imaging

Fractal dimension analysis has become an essential tool to assess the pore structure of various porous geomaterials including shale rock. In this regard, changes of fractal dimension during the thermal maturation of organic rich shale could represent the evolution of its pore structure. To this end, complementary tests were conducted on six organic rich shale samples that are in a wide range of thermal maturity (equivalent Ro values of 0.52–3.53 %). Fractal dimensions were obtained from small-angle neutron scattering (SANS), N2 physisorption, and field emission-scanning electron microscopy (FE-SEM) data. Herein, surface fractal dimensions were calculated from the N2 adsorption isotherms using the Frenkel–Halsey–Hill method, which was found between 2.46 and 2.71. Power-law exponents (E) of the SANS profiles varied from 2.75 to 3.48, indicating that both surface fractals and mass fractals would characterize the shale samples. As thermal maturity progressed, the fractal dimension shifted from surface to mass fractal while further analyses suggested this was caused by changes in the number density of pores (NDP) of various pore-size ranges. Ultimately, the pore size of the samples during such transition decreased with the increase of Ro.

Unveiling the petrographical, palynological, palynofacies and geochemical archives of coal and shaly coal deposits in the Mandakini–B block of Talcher Basin: An insight into the paleoecology, depositional environment, kerogen type and source rock potential

Coal and shaly coal beds in the Talcher-Mahanadi Basin, eastern India, belongs to Barakar Formation (Artinskian). A comprehensive analysis was undertaken, including organic petrography, palynology, palynofacies, proximate analysis, Rock-Eval pyrolysis and Field Emission Scanning Electron Microscopy (FE-SEM). The samples consist of the vitrinite group of macerals (avg. 38.2 vol.%), followed by inertinite and liptinite, suggesting peat-forming higher plant vegetation was deposited under prevailing anaerobic conditions. However, the significant presence of inertinite macerals (avg. 29.2 vol.%), including semifusinite and fusinite, along with opaque phytoclasts (avg. 17.3 %), implies occasional shift to oxic conditions. High occurrence of tissue-derived phytoclasts (avg. 64.3 %) indicates that higher plants were the primary contributors to peat formation. Detrovitrinite sub-groups and non-biostructure phytoclasts suggests contributions from herbaceous flora and/or potential tissue degradation due to microbial activity. The palynomorph distribution reveals the dominance of Glossoptriadales, followed by Coniferales and trilete spore groups, comprising 25 genera and 40 species. Non-striate bisaccate pollen, primarily Scheuringipollenites (15–34 %) and sub-dominant striate bisaccate pollen Faunipollenites (11–18 %) prevail in the palynoassemblage. Petrographic indices suggest that the deposition of peat-forming telmatic vegetation has largely occurred in wet forest swamp conditions within the mesotrophic hydrological setting. Palynofacies data, plotted on Tyson’s APP (Amorphous organic matter-Phytoclast-Palynomorph) ternary diagram, suggests suboxic to dysoxic deposition conditions. Low phytoclast preservation index (PPI) indicate proximal deposition of the organic matter. Vitrinite reflectance (VRo%) ranged between 0.42 and 0.68 %, suggesting that the coalification reached up to ‘Medium rank D’ or Bituminous D stage. The substantial total organic contents (TOC: 34.02–61.84 wt.%), hydrogen index (HI) (avg. 154 mg HC/gTOC) and dominance of vitrinite maceral/non-opaque phytoclasts indicate Kerogen Type III and have significant potential for gaseous hydrocarbon generation. FE-SEM images reveal well-developed intergranular and organic pores within the matrix system, serving as both a source and storage in coal beds.

Zeolite-Based Poly(vinylidene fluoride) Ultrafiltration Membrane: Characterization and Molecular Weight Cut-Off Estimation with Support Vector Regression Modelling.

Zeolite serves as a promising additive for enhancing the hydrophilicity of polymeric membranes, yet its utilization for bolstering the mechanical strength of the membrane remains limited. In this study, poly(vinylidene fluoride) (PVDF) membranes were modified by incorporating various concentrations of zeolite (0.5-2 wt%) to improve not only their mechanical properties, but also other features for water filtration. Membranes with and without zeolite incorporation were fabricated via a dry-wet phase inversion technique, followed by the application of a series of characterization techniques in order to study their morphological structure, mechanical strength, and hydrophilicity. The membrane filtration performance for each membrane was evaluated based on pure water flux and Bovine Serum Albumin (BSA) rejection. Field-Emission Scanning Electron Microscopy (FESEM) images revealed a dense, microvoid-free structure across all of the PVDF membranes, contributing to a high pristine PVDF membrane tensile strength of 14 MPa. The addition of 0.5 wt% zeolite significantly improved the tensile strength up to 19.4 MPa. Additionally, the incorporation of 1 wt% zeolite into PVDF membrane yielded improvements in membrane hydrophilicity (contact angle of 67.84°), pure water flux (63.49% increase), and high BSA rejection (95.76%) compared to pristine PVDF membranes. To further improve the characterization of the zeolite-modified PVDF membranes, the Support Vector Regression (SVR) model was adopted to estimate the molecular weight cut off (MWCO) of the membranes. A coefficient of determination (R2) value of 0.855 was obtained, suggesting that the SVR model predicted the MWCO accurately. The findings of this study showed that the utilization of zeolite is promising in enhancing both the mechanical properties and separation performance of PVDF membranes for application in ultrafiltration processes.

Targeted Drug Delivery through the Synthesis of Magnetite Nanoparticle by Co-Precipitation Method and Creating a Silica Coating on it

Billions of dollars are spent annually in the world to treat and investigate problems caused by drug side effects. According to the estimation of health researchers, a huge part of people who take medicine suffer from complications caused by it. In this way, the necessity of using a targeted system in order to deliver medicine to the targeted place without damaging healthy tissues is felt more than before. In recent years, targeted drug delivery systems based on nanoparticles have received much attention. In the same direction, in this research, co-precipitation method was used to prepare magnetic nanoparticles using iron(|) and iron(||) oxides, and further, according to the synthesis steps of magnetite nanoparticles (MNPs) and the mechanism of formation and identification of magnetite nanoparticles ( Fe3O4) by examining the infrared pattern (FT-IR) obtained from Fe3O4 nanoparticles, the results of the magnetometric test (VSM) of Fe3O4 nanoparticles, X-ray diffraction pattern (XRD) of Fe3O4 nanoparticles, Field Emission Scanning Electron Microscope (FE-SEM) images obtained from Fe3O4 nanoparticles was discussed. After this stage, silica- coated iron nanoparticles (Fe3O4@SiO2) were prepared, and the infrared (FT-IR) pattern of Fe3O4@SiO2) was also investigated. It is worth mentioning that the mechanism of formation and identification of magnetic silica-coated iron nanoparticles (Fe3O4@SiO2) has been described in detail. Therefore, the obtained results indicate that the drug can be guided in a controlled and targeted manner by the magnetic field, and the results of the FE-SEM images show that the obtained product has a spherical morphology and the particle size distribution was less than 100 nm. Therefore, spherical shape and the symmetry of these particles can be helpful for their movement in the liquid mediu.

Influence of synthesis route on structural properties of SnFe2O4 spinel phase via methods of co-precipitation, sol–gel and solvothermal: morphology, phase analysis, crystallite size and lattice strain

In this study, regarding to the wide applications of spinel ferrites in various fields such as Li ion-batteries, photocatalysts, and optoelectronics, the structural and morphological properties of tin ferrite oxide (SnFe2O4) nanoparticles are investigated using X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FESEM). The sol–gel, solvothermal, and co-precipitation methods were used to synthesize the SnFe2O4 nanoparticles, and the effect of annealing temperatures at T = 350 °C, 450 °C, and 550 °C was investigated. The XRD results confirmed the formation of tin ferrite spinel phase at an annealing temperature of 350 °C with a preferred peak (311). Crystallite size (D) and strain (ε) of SnFe2O4 nanoparticles was determined in region 20–45 nm and 2–4 × 10–4, respectively, using the Scherer, Williamson–Hall, and Rietveld computational methods. The results showed that the crystallite size in the samples increased with increasing annealing temperature. This increase is attributed to the reduction of defects, imperfections and lattice strain, which leading to an increase in the lattice constants and unit cell volume in the nanocrystalline structure. The Rietveld method determine smaller crystal sizes compared to the Williamson–Hall and Scherer methods because it can correct for peak broadening by taking into account all instrumental factors. The FESEM images of the synthesized nanostructures of SnFe2O4 showed cubic and polyhedral grains with cluster growth and an average grain size of 50–80 nm. According to the crystal structure of tin ferrite spinel, the cubic morphology confirmed the formation of this structure. The average crystallite size and grains in the synthesized samples was determined using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) analysis, respectively. The formation conditions of the SnFe2O4 spinel phase and other phases in the synthesis process at different temperatures and dependence of structural parameters was studied by various structural models for the samples.

Graphene aerogel based positive electrode for lithium ion batteries

In this study, a composite of LiNi0.8Mn0.1Co0.1O2 nanoparticles (nNMC-811) supported by three-dimensional (3D) graphene aerogel (GA) was prepared to increase the practical energy density and performance capability of high nickel cathodes. The porous LiNi0.8Mn0.1Co0.1O2 nanoparticle/graphene aerogel (nNMC-811/GA) composite is composed of nNMC-811 and graphene that act as a bridge for electron transfer and acceleration of lithium ion diffusion. nNMC-811 and nNMC-811/GA cathodes characterization data with techniques including X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectroscopy (XPS) are discussed. Both Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM) made clear observations of the uniform distribution of the cathode active powders over the 3D graphene aerogel structure. The electrochemical performance of the nNMC-811 and nNMC-811/GA cathodes was evaluated by the galvanostatic charge-discharge measurement between 2.5 V and 4.5 V at room temperature using a computer-controlled battery tester. In addition, variable speed capacity ratios (C-rate), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) analyzes were also performed. nNMC-811/GA hybrid composite structure delivers a specific capacity of 183.15 mAhg−1 at C/2 after the 500th cycle. It is understood from the FE-SEM images taken after the cycle that there is no deterioration in the structure. According to results, it was observed that the 3D porous structure of the nNMC-811/GA composite facilitated the mobility of Li+ ions, and the excellent electrochemical performances of the cathodes were improved due to the increasing defects as well as the electrical conductivity of GA.

Structural, morphological, and EMI shielding evaluations of Sm-Mn co-doped Sr-based M-type hexaferrite for Ku band applications

High-performance, thin, and lightweight EMI (Electromagnetic interference) materials with outstanding shielding effectiveness were explored over the last years to solve the problems in electronic devices. Magnetic absorbing materials have extensive bandwidth, good impedance matching, and excellent absorption features. In the present study, Sm-Mn Sr-doped M hexaferrites with Sr1-xSmxFe12-yMnyO19 whereas (x= 0.00, 0.025, 0.05, 0.075, y = 0.00, 0.25, 0.5, 0.75) were prepared by the chemical route. XRD, FESEM, HRTEM, FTIR, VSM, and VNA are used to evaluate the properties of the Sm-Mn doped Sr-based M-type hexagonal ferrite. The XRD (X-ray diffraction) results revealed the presence of a hexagonal phase in the prepared samples. Rietveld refinement also confirmed the phase purity for the Sm-Mn doped Sr-based M-type hexagonal ferrites. The FESEM (Field emission scanning electron microscopy) and HRTEM (High-resolution transmission electron microscopy) images revealed the hexagon-type shapes of the particles in the Sm-Mn doped Sr-based M-type hexagonal ferrites. The FTIR (Fourier transform infrared spectroscopy) spectra showed the 446 to 620 cm-1 lines, confirming the presence of the tetrahedral and octahedral phases of hexagonal ferrites. Dielectric and electromagnetic shielding effectiveness (SE) parameters are evaluated for Sm-Mn doped Sr-based M-type hexagonal ferrite. The electromagnetic parameters, such as complex refractive index, absorption and impedance, are also investigated for the Sm-Mn doped Sr-based hexagonal ferrite powder with x=0.075, y=0.75 having epoxy resin with 20wt%, 30wt% and 50wt% samples, respectively. SE parameters are higher at more extensive filler loading. The green shielding index was found higher for Sm-Mn doped Sr-based hexagonal ferrite powder with x=0.075, y=0.75 having 20wt% epoxy resin and decreased with filler loading. It is found the epoxy/Sm-Mn doped Sr-based M-type hexagonal ferrites-based composites are excellent absorbers in the Ku band. The investigated absorbers could be the best candidates for next-generation EMI green shielding absorbing devices and applications.

Optical and electrochemical properties of manganese oxide (Mn3O4) nanoparticles: Investigating the influence of calcination temperature on supercapacitor performance

In this study, we investigate the influence of calcination temperature on the structural, optical, and electrochemical properties of Mn3O4 nanoparticles synthesized through a chemical co-precipitation route. Field-Emission Scanning Electron Microscopy (FESEM) images depict the formation of highly agglomerated, spherical-shaped particles. At calcination temperatures of 700 °C and 900 °C, the observation reveals the emergence of flat pellets and rod-like structures. The X-ray Diffraction (XRD) patterns confirm the presence of the Mn3O4 phase in M0 and M1 samples. However, the sample calcined at 500 °C (M3) showed a mixed phase of Mn3O4 and Mn2O3. Upon further calcination at 700 and 900 °C, this mixed phase undergoes complete transformation into the Mn2O3 phase. The change in absorption onset and photoluminescence intensity of samples is found with an increase in calcination temperature due to the crystal growth and phase modification. Furthermore, the synthesized samples are employed as electrode materials for supercapacitor applications. The sample calcined at 300 °C (M1) in three-electrode system demonstrated the specific capacitance (Csp) of 273.3 F/g at 0.5 A/g in an alkaline medium. The asymmetric cell assembled by using M1 and Hibiscus cannabinus stem-derived carbon material (HBC-900) delivered higher Csp of 205.7 F/g at 0.5 A/g. In addition, asymmetric supercapacitor device exhibited a high energy and power density of 43.1 Wh/kg and 476.2 W/kg with 82.07 % of initial Csp retention over 10,000 cycles at 10 A/g, which makes the sample M1 as the potential electrode material for supercapacitor application.

Influence of NaOH Concentration on Structural, Morphological, Optical, and Electrical Characterization of Perovskite Sodium Bismuth Titanate Prepared by Hydrothermal Method

The hydrothermal method successfully prepares a lead-free sodium bismuth titanate (NBT) perovskite film. The prepared films were studied structurally, and morphologically using X-ray diffraction, and field-emission scanning electron microscopy (FESEM), respectively. Varying the concentration of NaOH showed a noticeable effect on the properties studied. Good crystallization of NBT perovskite films without impurities was obtained at 18 and 20 M concentrations, where the crystalline size was 14 nm according to the Scherer equation. Also, when varying the concentration of NaOH, a similar film thickness was obtained through a cross-section of the FESEM images. It was observed that there was a difference in the intensity of the peaks of the photoluminescence spectra of the prepared films with a change in the concentration of NaOH, which confirms a change in the concentration of oxygen vacancies. The activation energy of the prepared films was deduced from the Arrhenius plot, as it showed small values in the films prepared with a low concentration of NaOH. The results showed that the maximum value of mobility of NBT films was at 20 M of NaOH concentration through the Hall Effect.

Structural and Electrical Properties of Li Substituted Mg Nano Ferrites: Prepared by Citrate-gel Auto Combustion Method

LixMg1−xFe2O4 where x=0.0to0.5with0.1 nano ferrites were synthesized by citrate gel auto combustion. Using a field-emission scanning electron microscope (FE-SEM) and the X-ray diffraction technique, their structural and topographical studies were examined. The prepared nano ferrites’ single-phase cubic spinel along the Fd3m space group is confirmed by the structural investigation. The synthesized samples were found to have a crystalline size of 20–26 nm, as determined by the Debye–Scherrer formula. Lattice parameter variation observed for the samples indicates dopant atoms into a crystal lattice can also lead to changes in the lattice constant. FE-SEM images revealed the clear grain and grain boundaries with agglomerated structure and it varied between 33.6 nm-24.4 nm. Two bands observed in Fourier transform infrared spectroscopy illustrates the M-O band in tetrahedral and octahedral sites. Dielectric parameters of the sample observed by LCR meter. Single semicircle behavior observed in impedance spectra. Dielectric constant and dielectric loss decreased as increasing frequency explained by Koop’s theory of mechanism. AC conductivity increasing trend observed with frequency, mobility of charge carrier active at high frequency domain.

Effect of oxidation temperature on physical properties of polycrystalline β-Ga2O3 grown by thermal oxidation of GaN in O2 ambient from 900 to 1400 °C

This study aimed to investigate the effect of oxidation temperature on the physical properties of β-Ga2O3 grown by thermal oxidation of GaN in the O2 ambient at high oxidation temperatures from 900 to 1400 °C. Notably, the analysis of the oxidation temperatures ranging from 1100 to 1400 °C remains unexplored in the other studies. The effects of the oxidation temperature on the physical properties were investigated via X-ray diffraction, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy (FESEM). At all oxidation temperatures, XPS results revealed oxygen deficiency. The top FESEM images indicated disordered nanocolumn structures on the surface of the oxide layer, which increased in abundance with oxidation temperatures exceeding 1100 °C. Energy-filtered high-resolution transmission electron microscopy images and the selected area electron diffraction patterns revealed that the top nanocolumns and the oxidized layer comprised polycrystalline β-Ga2O3. Additionally, the cross-sectional lamellae prepared through focused ion beam milling revealed an increase in the thickness of the β-Ga2O3 layer with oxidation temperature. To account for the variations in the oxide layer thickness, the oxidation temperatures were classified into two ranges of 900–1100 °C and 1100–1400 °C for calculating the activation energy. Moreover, this study assumed that the activation energy required for the oxidation process remained constant within each temperature interval. According to Arrhenius's model, the activation energy from 900 to 1100 °C was calculated to be 286.15 kJ/mol (2.97 eV). Furthermore, the activation energy from 1100 to 1400 °C was determined to be 111.33 kJ/mol (1.15 eV).

Comparative Study of Rare Earth Nd and Sm Doping on the Structural, Morphological, Optical, Magnetic, and Electromagnetic Traits of Mg-Zn-Cu Spinel Nanoferrites

In the current study, the magnetic nanoparticles of neodymium and samarium substituted Mg-Zn-Cu, with a chemical composition of Mg0.5Zn0.5Cu0.05RxFe1.95-xO4 (x = 0.05; R = Nd, Sm) were produced via the sol-gel auto-combustion route. XRD indicates the evolution of a cubic symmetry having Fd3m space group and no impurities at the room temperature. The FESEM images show the irregularly shaped and agglomerated grains in all samples. FTIR examination reveals the stretching vibrations among the metal cations and anions at interstitial vacancies. The M-H graphs demonstrates that the prepared nanoferrites have low rentivity (0.18–0.84 emu g−1) and coercivity (11.25–34.03 Oe) indicating the formation of superparamagnetic nature. From the electromagnetic traits, the observed sample’s real magnetic permeability (μ″) and permittivity (ε′) along with dielectric loss and magnetic loss reduced with increasing applied field frequency, indicating the typical behaviour of spinel nanoferrites. This may be explained by Maxwell-Wagner interfacial polarisation and the electron hopping among the ferrous and ferric ions. The variations in coercivity, anisotropy constant, and electromagnetic traits provide strong evidence that all of the samples are thermally stable and have the potential to be used in solenoids and transformers, and also, in the more resistive devices that operate at the high frequency.

The influence of the physicochemical processes on the electrical response of Al/p-Si structure with etched surface

In this paper, the electrochemical etching process is used for surface modification of the p-Si wafer, named as porous silicon (PS), in the metal–semiconductor (MS) type Schottky diode (SD) with a structure of Al/p-Si. Five regions of PS wafer with different etching rates are selected for comparison of them which are called P2, P3, P4, and P5 (P1 is the reference area without porosity). The morphological, structural, and electrical properties of the PS used in the MS-type SD are investigated using field-emission scanning electron microscope (FE-SEM) images, energy dispersive X-ray (EDX) analysis, and current–voltage (I–V) characteristics, respectively. The FE-SEM images show a meaningful effect on the porosity. The EDX spectrum demonstrates the importance of the chemical effects in addition to the physical changes in the porosity process of the p-Si wafer. The reverse-saturation current (I0), ideality factor (n), barrier height at zero-bias (ΦB0), and series/shunt electrical resistances are also computed and compared. Some of these parameters (n, Rs, BH) are determined using different methods, namely Thermionic emission (TE), Cheung functions, and modified Norde, and they exhibit strong agreement with each other. The energy-dependent profiles of surface states (Nss) are estimated from the I–V data by considering the voltage dependence of ΦB (V) and n(V). All the experimental findings indicate that the etching process of the p-Si wafer significantly influences the electrical performance of the Al/p-Si Schottky diode by increasing the extent of etching.

Field application of Ca-doped ZnO nanoparticles to maize and wheat plants

Nanoparticles play a vital role in modern agriculture to provide the nutrients required by plants. Herein, we report the preparation of calcium-doped zinc oxide nanoparticles (CZO NPs) via a simple and cost-effective co-precipitation method, with the aim of realizing increased fertilizer response. The synthesized nanoparticles were analyzed to study their physicochemical properties using various characterization techniques. The X-ray diffraction pattern showed a small shift in peak position towards higher values of 2θ and reduced crystal size after the zinc oxide (ZnO) matrix had been doped with Ca. Field-emission scanning electron microscopy images clearly revealed a grain-like surface morphology. The X-ray photoelectron spectroscopy study produced evidence of Zn2+ substitution by Ca2+ and enhanced Zn–O bond strengths in the CZO samples. Two major crops, maize (Zea mays L.) and wheat (Triticum aestivum L.) were selected to study the impact of the CZO NP-based nanofertilizer on plant growth. During the study, the effect of the CZO-based fertilizer on growth parameters such as seed germination, root and shoot length, plant height, root and stem width, number of leaves, and leaf size was studied based on comparisons with control plants. We observed significantly increased plant growth parameters after the application of the CZO NP-based fertilizers.

Characterization of Ce3+ and Eu3+ doped and co-doped ZnO nanoparticles for luminescence applications

This paper investigates the synthesis of Ce3+ and Eu3+ doped, as well as co-doped ZnO nanoparticles using the solution combustion route. The nanoparticles exhibit a hexagonal wurtzite structure of ZnO with crystallite sizes ranging from 19 to 22 nm. Structural parameters, including lattice constants, bond lengths, and bond angles, are evaluated. Morphological diversity is observed in field-emission scanning electron microscopy images. The diffuse reflectance spectroscopy results reveal an energy band gap of 3.20 eV for undoped ZnO nanoparticles. The energy band gap value slightly decreases for Eu-doped ZnO and certain (Ce, Eu) co-doped ZnO nanoparticles. Photoluminescence (PL) excitation peaks are attributed to energy levels of native defects in the ZnO band gap, along with f–d and f–f transitions of rare-earth ions (Ce3+, Eu3+). The PL emission spectra under different excitation wavelengths (350 nm, 394 nm, and 465 nm) display varied peak positions. ZnO co-doped with 0.96 mol% of Ce3+ and 0.92 mol% of Eu3+ emerges as a promising material for luminescence applications, exhibiting a significant increase in green emission intensity. Consequently, this study represents a novel contribution to the field of ZnO-based luminescent materials.

Glass Transition Temperature and Mechanical Properties of Poly(Ethylene Carbonate)/Organoclay Composites

Poly(ethylene carbonate) (PEC) is a form of aliphatic polycarbonate, a biodegradable polymer made via the copolymerization of carbon dioxide and epoxides. The poor thermal stability and mechanical properties of these aliphatic carbonates are attributed to the carbon structure's flexibility, which restricts their applications. By combining PEC with organoclay CP180, this study addressed the weaknesses of PEC with organoclay addition. A physical blending technique was employed to generate PEC/organoclay composites with a 10-50 wt.% ratio of organoclay. The blended material's thermal characteristics were analyzed using differential scanning calorimetry (DSC), and the mechanical characteristics were measured using a universal tensile machine. The Field Emission Scanning Electron Microscopy (FESEM) analysis determined the blends' morphology. Before the torque value for all curves grew with the addition of CP180 material to the PEC matrix, it became constant. It reached a high value due to the shear-thickening behavior of the PEC matrix with organoclay addition. Tg of PEC increased by more than 7°C by 40 wt.% organoclay addition, as evident in the hindrance of PEC flexibility, significantly increased the toughness of this PEC. From the FESEM images, the formation of large silicate starts to aggregate effectively, lowering the interfacial area between organoclay and PEC as the clay content continues to rise, as shown by 50 wt.% organoclay addition.

Synthesis of cerium-doped gadolinium gallium aluminum garnet (GGAG:Ce) scintillating powder via solvothermal method

The powder material Gd3Ga3Al2O12:Ce (GGAG doped with Cerium) has garnered significant attention in radiation detection due to its high light yield and rapid decay time. Despite its potential, the synthesis of high-quality and reproducible GGAG:Ce scintillating powder remains a considerable challenge. In this study, we present a solvothermal approach with an annealing temperature of 1300 °C for producing cerium-doped GGAG powder with varying concentrations (4, 2, and 0.5 mol%). The structural and luminescent characteristics were meticulously examined using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL), radioluminescence (RL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). XRD analysis confirmed the single-cubic phase garnet structure of the synthesized powder. By comparing the intermediate solvothermal products synthesized at different sintering temperatures (900 °C for 3 h and 1300 °C for 1 and 3 h), a direct correlation between solvothermal conditions and the structure/property relationships of the product was established. FESEM images revealed an ellipsoidal to irregular morphology of the as-synthesized GGAG:Ce microparticles, ranging from 0.1 to 0.3 μm, regardless of the Ce concentration. PL spectra demonstrated a strong emission peak at approximately 550 nm, characteristic of Ce3+ ions. RL data confirmed the peak luminescence at around 550 nm, with an almost twofold increase in intensity as the concentration of Ce3+ increased from 0.5 mol% to 4 mol%. XPS data disclosed the Ce3+/Ce4+ ratio in solvothermally synthesized GGAG:Ce, wherein Ce loading of 4 mol% demonstrated the increase in Ce3+ concentration to 95%, whereas the concentration of Ce4+ decreased to 5%. Notably, the highest luminescence efficiency was achieved with GGAG:Ce at a 4 mol% concentration. Thus, the solvothermal method employed in GGAG:Ce synthesis presents a straightforward approach, yielding rapid results with precise control over particle morphology and size.

Biopolymer blend composite films based on polyvinyl alcohol/ chitosan/ grape seed extract via green approach for flexible optoelectronic devices

The flourishing environmental concerns have grabbed the attention of researchers developing environmentally supportive materials in various fields. A green approach was used to create biopolymer blend composites based on polyvinyl alcohol (PVA) and chitosan (CS) doped with various concentrations of grape seed (GS). Various analytical techniques, such as Fourier-transform infrared spectroscopy (FTIR), UV–visible (UV) spectra, field emission scanning electron microscope (FE-SEM) and differential scanning calorimetry (DSC) were used to evaluate the optical, structural and thermal properties of the prepared blend composites. The optical properties of blend composites were determined by UV spectroscopy and the findings revealed that absorption intensity increased with increasing GS, while bandgap energy decreased from 4.18 eV for pure blend to 2.91 eV for blend/15 wt% GS. The homogeneous distribution of GS particles in the biopolymer blend was identified with FE-SEM images. DSC results showed that increasing the GS content increased the glass transition temperature of the blend composites. The AC conductivity and dielectric constant were measured using the LCR meter. The conductivity rises with increasing frequency and dosage of GS, with the greatest conductivity obtained at 15 wt% loading. In comparison to a pure blend, it was discovered that the inclusion of 15 wt% GS enhanced the tensile strength by 50%, hardness by 17% and the reduction in elongation at break by 19 %. As a consequence, environmentally friendly PVA/CS/GS biopolymer blend composites with excellent mechanical, thermal, electrical, and dielectric parameters might be a viable green option for flexible electronic, electrochemical and energy storage devices.