Field Emission Scanning Electron Microscopy Images Research Articles

Phase-selective fabrication of Cu-based films by magnetic field-assisted sparking process for improved photocatalytic dye degradation and CO2 reduction

Copper-based films (Cu2(OH)3NO3, Cu2O, and CuO) were successfully synthesized using a sparking process under an external magnetic field, without requiring an annealing process. We thoroughly investigate the impact of magnetic field orientation on the structural, morphological, and optical properties of the films, along with their performance in photocatalytic degradation of methylene blue (MB) and carbon dioxide (CO2) reduction. Field-emission scanning electron microscopy (FE-SEM) images reveal that the CuEB(S) sample displays secondary particles forming spherical, dense clusters, whereas the CuEB(N) sample exhibits larger, loosely packed clusters. In contrast, the cluster-like structures disperse in the CuEB(P) sample, resulting in a smoother film surface aligned with the parallel magnetic flux direction. Upon close observation, rice-shaped particles of varying sizes (26.3–60.3 nm) were found stacked together. This study presents a facile method to selectively fabricate films comprising single-phase Cu2(OH)3NO3, a CuO/Cu2O composite, or a combination of all phases by manipulating the external magnetic field orientation during the sparking process. All synthesized materials exhibit photocatalytic activity, with the heterojunction composed of CuO, Cu2O, and Cu2(OH)3NO3 demonstrating superior performance. This heterostructure achieved up to a 180 % enhancement in MB degradation and approximately doubled the CO2-to-CO conversion rate to 16.09 μmol g–¹ h–¹ compared to the sample prepared without a magnetic field.

One-pot synthesis of graphene nanosheets‑nickel cobalt LDHs nanocomposite for electrocatalysis of oxygen evolution reaction

Oxygen evolution reaction (OER) is known as a bottleneck for the overall water-splitting process due to its slow kinetics. In this regard, constructing a high-performance, cost-effective electrode material may act as a game changer. Here, a 2D/2D nanocomposite has prepared out of graphene nanosheets and nickel‑cobalt layered double hydroxide (NiCo LDH) by a simple solvothermal method. The 2D flower-like structures of NiCo LDH attached to graphene nanosheets have observed in field-emission scanning (FE-SEM) and transmission (TEM) electron microscopy images. The X-ray diffraction (XRD) patterns have revealed the formation of Ni(OH)2 and Co(OH)2 lattices along with hexagonal graphene crystals. X-ray energy dispersive spectroscopy (EDS) has noted the 2.2:1 ratio of nickel to cobalt in the graphene/NiCo LDH nanocomposite. X-ray elemental maps have shown the uniform distribution of elements in the sample, and the corresponding functional groups have observed in the Fourier-transform infrared (FTIR) and Raman spectra. X-ray photoelectron spectroscopy (XPS) has determined the coexistence of divalent and trivalent metals in the nanocomposite. The N2 adsorption-desorption study has shown signs of slit-shaped ion-accessible micro and mesopores with high specific surface area for the nanocomposite. It has benefited the ion diffusion process during the exposure of the modified electrode to the electrolyte. The graphene/NiCo LDH nanocomposite has provided the onset potential of 1.56 V, overpotential of 338 mV at 10 mA cm−2, Tafel slope of 69 mV dec−1, charge-transfer resistance (Rct) of 27 Ω, double layer capacitance (Cdl) of 24 μF, electrochemically surface area (ECSA) of 0.6 cm2, and roughness factor (RF) of 20. The electrode has maintained 98.3 % of its initial signal after 10 h continuous measurement at OER potential. This electrocatalytic activity refers to the sheet-like morphology, effective hydroxide ion transfer through interlayer spaces, enhanced conductivity, and high chemical stability achieved by a constructive synergy between graphene nanosheets and NiCo LDH.

Formamidinium Lead Iodide‐Based Perovskite Solar Cell Fabrication With an Electrospun‐Reduced Graphene Oxide Back Electrode: A Novel Approach

AbstractIn this work, low‐cost and simple structure perovskite solar cells (PSCs) were fabricated using formamidinium lead iodide (FAPbI3) as the light absorber and reduced graphene oxide nanofibers (rGO NFs) as the counter electrode (CE). The FAPbI3 light absorber was prepared using a two‐step solution process, whereas the rGO NFs were synthesized through a simple electrospinning method. The as‐prepared FAPbI3 and rGO NFs were characterized by high‐resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X‐ray diffraction (XRD) pattern analysis. The surface morphology of the as‐prepared FAPbI3 and rGO NFs showed crystalline and bead‐free fiber structures, as confirmed by HRTEM and FESEM image analysis. The AFM topographical images of FAPbI3 and rGO NFs further reveal the crystalline and fiber structures. XRD pattern analysis confirmed the cubic crystalline phase of FAPbI3 and the graphitic nature of rGO NFs. From the electrochemical impedance spectroscopy studies, the PSC assembled with the FAPbI3 light absorber and rGO NFs‐based CE demonstrated an electrical conductivity of 3.64 × 10−4 S cm−1. The fabricated PSC device achieved an efficiency of 8.78% compared to the 7.49% efficiency of the device with a sputtered gold CE. This work uniquely integrates advanced materials, cost‐effective manufacturing, and enhanced efficiency in PSCs using FAPbI3 light absorbers and rGO NFs, addressing key challenges in cost and sustainability in solar technology.

Fabrication of Zinc Oxide Thin Films by Sol-Gel Dip Coating Process

Zinc oxide (ZnO) is a non-toxic material known for its distinctive physical and chemical properties, including a direct band gap energy of 3.37 eV and a large exciton binding energy of 60 meV, which contribute to its significant thermal and chemical stability at room temperature. Due to these characteristics, ZnO plays a critical role in various applications, such as UV light emitters, transparent conducting thin films in electronic devices, gas sensors, piezoelectric materials, transducers, and as a transparent conductive oxide (TCO) layer in thin-film photoelectrochemical cells. Numerous fabrication techniques have been employed to produce ZnO thin films. However, many of these methods require costly equipment, high vacuum environments, and elevated temperatures. In contrast, the sol-gel process stands out as a convenient, cost-effective, and versatile method for ZnO thin film fabrication. It offers advantages such as simplicity, low crystallization temperature, ease of reproducibility, molecular-level homogeneity, and precise compositional control. In this study, ZnO thin films were deposited onto Indium Tin Oxide (ITO) glass substrates using the sol-gel dip coating method, with varying preparative parameters: sol concentrations and annealing temperatures. The resulting samples were characterized using a UV-visible spectrophotometer, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDX). The results demonstrated that the unique properties of ZnO thin films are highly dependent on the preparative parameters. Specifically, the band gap energy decreased from 3.25 eV to 3.18 eV with increasing sol concentration and also showed a similar decline with higher annealing temperatures. XRD patterns revealed a smaller full width at half maximum (FWHM) of the most intense peak (002) at higher sol concentrations and annealing temperatures, indicating an increase in crystallite size. FESEM images highlighted distinct morphological changes corresponding to the variations in sol precursor concentration and annealing temperature, while EDX analysis confirmed the formation of highly pure ZnO thin films on ITO glass substrates.

Studies on the retarded recrystallization of tungsten in CIMPLE-PSI exposed under very-high target temperature and long He+-fluence

Abstract Experiments are carried out in CIMPLE-PSI, to understand the recrystallization behavior of tungsten (W) exposed under very-high target temperature and ITER relevant long He+-fluence. The effect of helium bubbles on possible retardation of the recrystallization process is also studied. W samples are simultaneously exposed under He plasma and annealed by the plasma heat-load, in contrast to previously reported experiments in literature, which were carried out sequentially. Exposed samples are characterized by field emission scanning electron microscopy (FESEM), Vickers surface micro-hardness, nano-hardness and electron backscattered diffraction (EBSD). It is observed that the sample exposed to plasma under the highest temperature (1866 K) suffered acute retarded grain growth. This also contained small, unrecovered grains on the exposed surface. FESEM imaging of the cross-sections confirm relatively smaller helium bubbles still form even at the very high temperature conditions, which can impede the grain growth locally, whenever they are forming right on the grain boundaries. This results in an inhomogeneous mixture of surface grains with sizes from few micrometer to few tens of micrometer. EBSD estimates that the plasma exposed surface was only 34% recrystallized. The second sample exposed at a lower temperature (1699 K) but for three times higher fluence (ion fluence: 1.19×1027 m-2) was almost fully recrystallized, which shows retardation diminishes very fast with the duration of the exposure. Hardness measurements were undertaken to understand the variation with plasma exposure/annealing temperature and the extent of recrystallization, with three different probing length scales, spanning from few hundreds of nanometer to several micrometers. Both helium plasma exposed W samples are observed to undergo retarded softening up to a depth of few hundred nanometers from the surface, compared to when the metal may be recrystallized by simple heating, without any plasma exposure.

Effects of Pt doping on surface properties and quenching of band edge emission in ZnO

Pt doped ZnO thin films were synthesized on soda-lime glass substrates using a cost-effective sol-gel method, followed by spin coating and thermal annealing at various temperatures. Several characterization techniques such as UV–Vis absorption spectroscopy, photoluminescence (PL), field emission scanning electron microscopy (FESEM), time-of-flight secondary ion mass spectroscopy (ToF-SIMS), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) are exploited to investigate the Pt doping effects on surface and optical properties of ZnO thin films. UV–Vis analysis demonstrated a slight decrease in the optical band gap from 3.3 eV to 3.2 eV with increased annealing, indicating enhanced suitability for optoelectronic applications. FESEM imaging revealed distinct worm-like structures and small Pt metal nanoparticles in unannealed samples, while thermal treatment supported the formation of spherical Pt nanoparticles and improved conductive pathways in the films. The Wagner diagram, coupled with Auger line transitions from XPS, quantified the oxidation states and chemical environments of Zn and Pt, respectively. Notably, the observed changes in the binding energy of the Zn-2p junction and the kinetic energy of the Zn-LMM Auger junction were significantly influenced by the Pt doping and the electronic properties of the substrate. The Wagner diagram provided a comprehensive visual representation of the parameters, facilitating a deeper understanding of electronic interactions and structural dynamics at the atomic level. XPS results confirmed the presence of ZnO, Zn(OH)2, Pt0 and PtO2 phases, indicating stability and constutient's interactions. ToF-SIMS also validated the uniform distribution of Pt nanoparticles within the ZnO thin film, confirming the effectiveness of the sol-gel method. As a result of Pt doping, PL studies revealed a large quenching effect on band edge emission in the UV and visible emission region of ZnO thin film, which is due to Pt acting as a recombination center for photogenerated carriers. Overall, our results highlight the influence of annealing and Pt incorporation on the optical and structural properties of ZnO thin films and highlight their potential applications for photonics and catalysis.

Effect of Various Carbon Coating Techniques on the Electrochemical Performance of Li4Ti5O12 Synthesized by Sol-Gel Method

This study aimed to prepare spinel carbon-coated Li4Ti5O12 (LTO/C) via sol-gel reaction and applied as a high-performance lithium-ion battery anode. The LTO powder was coated using various carbon sources, super P (SP), sugar and PVDF-assisted SP. The crystal structure, morphology, conductivity and electrochemical performance of the samples were examined using X-ray diffraction (XRD), Field Emission scanning electron microscopy (FESEM), Fourier Transform Infrared (FTIR) spectroscopy, Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry/Charge-discharge (CV/CD), respectively. The XRD analysis results showed that the samples contain highly crystalline spinel LTO as the main phase and rutile as impurity. The FESEM image showed that SP covers the entire LTO surface more homogenous than sugar. However, sugar carbon makes roughness on the LTO surface. FTIR spectra showed that the coating using sugar and PVDF still contain hydrocarbon element. Electrochemical performance evaluations showed that SP carbon-coated-LTO possesses higher lithium diffusion and specific capacity than pure LTO, while sugar-coated-LTO shows the lowest specific capacity. Moreover, the SP carbon-coated-LTO sample high-rate capability has improved during full cell evaluation, delivering a discharge capacity of 249, 231, 211, 194, 58, and 23 mAhg-1 at the charge or discharge current density of 0.05, 0.1, 0.5, 1, 5, and 10 C, respectively.

Multifunctional 3D-Printed Thermoplastic Polyurethane (TPU)/Multiwalled Carbon Nanotube (MWCNT) Nanocomposites for Thermal Management Applications

In this work, multiwalled carbon nanotubes (MWCNTs) were melt-compounded into a novel thermal energy storage system consisting of a microencapsulated paraffin, with a melting temperature of 6 °C (M6D), dispersed within a flexible thermoplastic polyurethane (TPU) matrix. The resulting materials were then processed via Fused Filament Fabrication (FFF), and their thermo-mechanical properties were comprehensively evaluated. After an optimization of the processing parameters, good adhesion between the polymeric layers was obtained. Field-Emission Scanning Electron Microscopy (FESEM) images of the 3D-printed samples highlighted a uniform distribution of the microcapsules within the polymer matrix, without an evident MWCNT agglomeration. The thermal energy storage/release capability provided by the paraffin microcapsules, evaluated through Differential Scanning Calorimetry (DSC), was slightly lowered by the FFF process but remained at an acceptable level (i.e., >80% with respect to the neat M6D capsules). The novelty of this work lies in the successful integration of MWCNTs and PCMs into a TPU matrix, followed by 3D printing via FFF technology. This approach combines the high thermal conductivity of MWCNTs with the thermal energy storage capabilities of PCMs, creating a multifunctional nanocomposite material with unique thermal management properties.

Mechanochemical synthesis and characterization of poly[(aniline-co-N-(4-sulfophenyl) aniline] nanofibers and its nanocomposite with titanium dioxide nanoparticles and study of their efficiency in hybrid solar cell

The advantages of polyaniline for application in new generation solar cells include its cost-effectiveness, environmentally friendly synthesis, remarkable stability, and the ability to modify the bandgap through the synthesis of its nanocomposites. But a challenge for its nanostructures is the limited solubility in non-toxic solvents, including water, which limits their processability in coating techniques. We overcame this challenge by synthesizing its copolymer with diphenylamine-4-sulfonate and its nanocomposite with titanium dioxide nanoparticles (TiO2NPs). So through a solid-state and template-free technique and using sodium diphenylamine-4-sulfonate, aniline hydrochloride salt, TiO2NPs, and FeCl3∙6 H2O as an oxidant, poly(N-(sulfophenyl)aniline) nanoflowers (PSANFLs), poly [(aniline-co-N-(4-sulfophenyl) aniline] nanofibers (PAPSANFs), poly(N-(sulfophenyl)aniline) nanofibers/titanium dioxide nanoparticles (PSANFs/TiO2NPs), and poly (aniline-co-N-(4-sulfophenyl)aniline nanofibers/titanium dioxide nanoparticles (PAPSANFs/TiO2NPs) were synthesized. Characterization of the synthesized samples was carried out through field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectra, ultraviolet-visible spectra (UV-Vis), cyclic voltammetry (CV), and elemental analysis (CHNS). The FE-SEM images clearly illustrate that the synthesized samples are of nanoscale dimensions. The band gap values of 2.23 eV for PSANFs/TiO2NPs and 1.96 eV for PAPSANFs/TiO2NPs nanocomposites were determined through electrochemical calculations based on cyclic voltammetry curves, showcasing the complementary properties of n and p semiconductors. Using doctor blade method to prepare films from synthesized materials and the architectural pattern of ITO│TiO2NPs│semiconductor sample│Al, all hybrid solar cells are fabricated. The I-V characteristics and power conversion efficiency (PCE) of the samples were examined and discussed. The PCE values for the four samples were found to be in the range of 0.20–0.82 %.

Low magnetic field alignment of carbon fibers in a polymer matrix for high-performance thermal interface materials

Carbon-based materials like carbon nanotubes, graphene nanoplatelets, graphite, and carbon fibers (CF) are highly promising fillers for enhancing the thermal conductivity of thermal interface materials (TIMs) due to their high thermal conductivity and low thermal expansion. Aligning these fillers can further improve thermal conductivity, but current alignment methods using high magnetic fields are impractical for industrial use. In this study, we investigated the enhancement of the thermal conductivity of CF–polymer composites by aligning CF fillers with a low magnetic field. We observed up to 17 times enhancement of the thermal conductivity (from 3.1 to 52.8 W/mK) in a CF–graphene–polymer composite film by vertically aligning the CF fillers with a magnetic field of 0.75 T. The analysis of the structural properties of the films using X-ray diffraction and field-emission scanning electron microscopy imaging confirmed that the crystalline c-axis of the graphite plates in the CF was oriented perpendicular to the magnetic field direction. The large anisotropy in the diamagnetic susceptibility of the laminated graphene structure of the CF flakes is at the origin of the filler alignment. Furthermore, the thermal conductivity of the composites showed a strong correlation with the degree of filler alignment, which was dependent on the CF–graphene hybridization and the type of polymer matrix. This study provides a scalable and cost-effective method for enhancing the physical properties of carbon composites by controlling their microarchitecture using a low magnetic field.

Integration of orange peel derived carbon quantum dots with TiO2 for enhanced photocatalytic degradation of brilliant green dye

Brilliant green (BG) dye is a non-biodegradable, highly venomous and coloured pigment. BG dye possesses remarkably high visibility even at small concentration that causes diarrhea and abdominal pain in humans when being ingested. In addition, it is harmful to living organisms and polluting aquatic environments. Hence, eliminating BG dye from contaminated water is an urgent need. In this report, a photocatalyst encompasses hydrothermally prepared titanium dioxide (TiO2) integrated with orange peel derived oxygenated carbon quantum dots (O-CQDs) was developed for effective removal of BG dye. The O-CQDs were prepared using a single step eco-friendly hydrothermal process and an intense green fluorescence was observed upon exposing the O-CQDs to far UV light irradiation (254 nm). The formation of TiO2/O-CQDs nanohybrid was confirmed through UV–Visible spectrophotometer, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) analyses. A random distribution of spherical shaped O-CQDs on the surface of TiO2 was clearly observed in FESEM images. The carboxyl groups present in O-CQDs not only increased interlayer spacing but also led to the attachment of TiO2 effectively. The TiO2/O-CQDs nanohybrid showed 94.70 % efficiency towards photocatalytic degradation of BG dye under UV light irradiation that was ∼20 % higher than the efficiency of pristine TiO2 photocatalyst. The presence of O-CQDs in the TiO2/O-CQDs nanohybrid boosted the photocatalytic degradation efficiency by enhancing UV light absorption and suppressing photo-generated electron–hole recombination. The integration of agricultural waste derived carbon with TiO2 by a facile synthesis method paves a way for large scale synthesis of TiO2/O-CQDs nanohybrid, which is anticipated to broaden its application potential in environmental remediation through photocatalytic degradation of organic compounds.

Influence of Calcination Temperature on the Physicochemical Properties of Synthesized Hydroxyapatite from Cow Bone Waste

The chemical similarity found in hydroxyapatite (HA) with natural bone makes it a popular choice for bone replacement. Therefore, in recent years, there has been an increasing tendency towards manufacturing HA from biological sources or waste, such as animal bone waste. Using naturally derived HA can benefit the economy, the environment, and human health. Therefore, this paper reports on the extraction of HA from cow bone waste using a simple and cost-effective technique. The bone powder was calcined in a furnace at temperatures ranging from 700°C to 1000°C for two hours. Then, the synthesized HA was characterized using a Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD). FESEM images revealed that HA particles with non-uniform spherical morphology were produced where the size increases with the calcination temperature. This finding is consistent with the average value of particle diameter measured at a temperature of 1000°C (0.783±0.268 µm) which is much greater than at a temperature of 700°C (0.272±0.128 µm). EDX analysis revealed that the Ca/P ratio value obtained in this study indicates non-stoichiometric HA production. XRD analysis shows that only the HA phase is present and there is no secondary phase generated from the calcination process. Meanwhile, FTIR analysis can detect the main group elements of the HA which were OH- and PO43-. The findings obtained in this study prove the effectiveness of this method in producing highly crystalline HA powder from cow bone waste using the thermal treatment method.

Anticorrosion and rheological properties of Calyptocarpus vialis extract as a green coating for mild steel in 2MH2SO4

This study assesses the rheological properties and corrosion inhibition efficacy of Calyptocarpus vialis (CV) extract, a wild plant in Asteraceae family. Shear and dynamic rheology studies show that CV extract has shear-thinning behaviour, with viscosity changes occurring at higher shear rates, most likely owing to aggregate formation. These aggregates may develop due to certain solvent characteristics and a jamming tendency is due to the presence of extract phytochemicals. Dynamic rheology confirms its viscoelastic nature. Corrosion inhibition effectiveness was investigated using Mild Steel (MS) in 2 M H2SO4, resulting in an 82.69 % inhibition with an extract concentration of 1 g/L. Adsorption isotherm indicates phytochemical adsorption on MS surface. Contact angles of polished MS (87.30°), with extract (80.10°), and without extract (51.25°) show decrease in wetting and increase in hydrophobicity which indicates that a thin protective layer is formed at MS surface. FE-SEM (Field Emission Scanning Electron Microscopy) images reveal that the CV extract forms a protective barrier on the MS surface, significantly reducing corrosion as compared to the unprotected surface exposed to the mild acid solution. Theoretical calculations, including Density Functional Theory (DFT) simulations, Monte Carlo (MC), and Molecular Dynamics (MD) simulations, support the experimental findings, elucidating phytochemicals adsorption on the MS surface. Further research is required to examine the scalability of CV extracts for industrial applications, as well as their long-term stability and efficacy in various corrosive conditions.

In-situ polymerized boehmite/ cashew gum/ polyvinyl alcohol/ polypyrrole blend nanocomposites with tunable structural, electrical, and mechanical properties for enhanced energy storage applications

This study describes the successful synthesis of boehmite (BHM) nanofiller-reinforced ternary blend nanocomposite films composed of polyvinyl alcohol (PVA), cashew gum (CG), and polypyrrole (PPy) using in-situ polymerization with water as the environmentally friendly solvent. The blend nanocomposites were characterized using Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). FTIR analysis revealed chemical bonding between BHM and the biopolymer matrix at1071 cm-1. FE-SEM images exhibited a uniform distribution of BHM nanofillers within the CG/PVA/PPy matrix, particularly at a 10 wt% concentration. The addition of BHM significantly enhanced the thermal stability and the glass transition temperature of the nanocomposites. The temperature-sensitive AC conductivity, activation energy, and dielectric properties were examined using an impedance analyzer. AC conductivity analysis revealed reduced activation energy (1.277 × 10⁻5 eV at 7 wt% BHM) and increased dielectric constant (from 565.28 to 4411.22). The ternary blend nanocomposite demonstrated a significant 60.2 % increase in tensile strength, reflecting enhanced force resistance, while hardness values ranged from 26 to 30, classifying the films as soft and flexible. Overall, the study highlights significant enhancements in the morphological, electrical, thermal, dielectric, and mechanical properties of the nanocomposite films, emphasizing their promising potential for energy storage applications.

The Role of Fabricated Coral Shell Powder in the Healing of Mandibular Bone Gap in Dogs

Background: The reconstruction of mandibular bone defects poses a real challenge and difficulty for surgeons; biomaterial bone substitutes are the most used material for reconstructing mandibular bone defects. Objectives: This study explored the role of fabricated hydroxyapatite (HAp) powder from the coral shell in healing critical size mandible gaps in dogs. Methods: HAp was prepared using the hydrothermal method from coral shells. Characterization of the fabricated coral shell was done by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive x-ray spectroscopy (EDX). The designed research was performed on 18 dogs of both sexes (mean weight: 20±0.5 kg, mean age: 2±0.6 years). The samples were divided into two equal groups. Animals underwent experimental defects at the ventral surface of the lower mandible about 14.5 mm. Results: The results of XRD represented high crystallinity, the EDX results indicated the surface morphology of distributed particles of calcium, phosphorous, carbon, and oxygen, respectively, and the FESEM results suggested that the surface morphology of HAp appears as a spherical particle that regularly distributed within the sample. In the HAp group, at 30 days, the FESEM images show that the defective gap completely closed, and the center of the defect was filled with a thick layer of osteoid matrix. Radiographically, the HAp group at 30 days post-surgery indicated a well-defined circular radiolucent bone gap at the caudal portion of the mandible, with a partially sclerosed margin. Macroscopically, at 30 days, the gap appears very small and is invaded by new bone formation. Conclusion: In conclusion, recycling HAp from coral shells has practical value in the reconstitution of the mandibular gap, and the radiological and critical properties of prepared HAp emphasize this outcome.

Influence of Sulfur Addition on The Physical and Photocatalytic Properties Biosynthesized Se-doped ZnO Nanoparticles

Abstract The objective of this study was to investigate the influence of Sulfur (S) addition to selenium-doped zinc oxide (Se-ZnO) nanoparticles on their physical properties and photocatalytic activity. S,Se-ZnO sample was prepared by adding 1wt% sulfur onto 4%Se-ZnO nanoparticles. In the synthesis procedure, microwave irradiation was used as heating power and matoa leaf extract was used as a bioreductor. The nanoparticles were characterized using UV-Vis Spectroscopy, X-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). The calculated band gap energies of Se-ZnO and 1% S,Se-ZnO are 2.38 eV and 2.62 eV, respectively. Both samples exhibit a hexagonal wurtzite structure. FESEM image of addition S reveals flower petal flake formations and decrease particle size of 187 nm. The photocatalytic activity of nanoparticles was evaluated through 4-nitrophenol (4-NP) degradation under UV-C irradiation. 1% S,Se-ZnO exhibits high photocatalytic efficiency compared to Se-ZnO, with a degradation percentage of 85.09% after 60 min and a reaction rate of -0.0315 min−1. Based on these results, the addition of S on Se-ZnO biosynthesized shows improve physical properties and efficient photocatalytic materials for pollutant removal.

Biosynthesis of Selenium and Copper Oxide Nanoparticles using Probiotic Bacteria against Food Spoilage Microorganisms

The study’s aim is to synthesize selenium (SeNPs) and copper oxide (CuONPs) nanoparticles using probiotic Lactobacillus acidophilus as a reducing agent. The biosynthesized probiotic Lactobacillus acidophilus selenium and copper oxide nanoparticles were known by color change. The characterization of SeNPs and CuoNPs was completed by Ultraviolet-visible (UV-VIS) spectroscopy, Field Emission Scanning electron microscope (FESEM), Atomic force microscope (AFM), X-Ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). These tests are utilized for detecting stability, morphology, size, crystalline nature and functional groups on nanoparticles prepared surface. Outcomes revealed appearance of the brick-red and green color, representing a specific color of selenium and copper oxide nanoparticles. It was also disclosed that UV-VIS spectroscopy indicated band absorbance at 236 and 264 nanometer of intense surface Plasmon resonance, manifesting the formation and stability of prepared SeNPs and CuONPs. The FESEM image displayed mulit-shapes between spherical and vaulted for selenium and copper oxide nanosized. XRD at 2 theta revealed crystalline selenium and copper oxide nanoparticles where the average size is 75.52-153.22 nm. FTIR revealed the presence of functional groups of the supernatant that act as stabilizing and reducing agents. The antibacterial activity of synthesized nanoparticles was studied against five different bacteria causing food spoilage. As a result of this study, selenium nanoparticle and copper nanoparticles were biosynthized successfully in less time and easy consuming way by green synthesis of the supernatant probiotic Lactobacillus acidophilus.

Physical properties of La:ZnO thin films prepared at different thicknesses using spray pyrolysis technique

Herein we investigate the impact of film thickness on the physical properties of Lanthanum (La) doped ZnO thin films. The films were fabricated using the spray pyrolysis technique with a consistent La content of 5 weight (wt) % in the initial solution. X-ray diffraction analysis indicated the presence of a hexagonal ZnO phase with preferred orientation along the (002) direction and no other phases were detected. The crystallite sizes were calculated using the Halder-Wagner equation, with a maximum size of 16.1 nm observed for a film thickness of 106 nm. Field-emission scanning electron microscopy (FE-SEM) images revealed the formation of a continuous film with an average grain size that increased as the thickness of the film increased. The grain size ranged from 74.5 to 136 nm as the film thickness varied from 106 to 426 nm. Films with lower thicknesses up to 196 nm exhibited two band gaps at approximately 3.2 and 4 eV, while films with higher thicknesses displayed a single band gap around 3.2 eV. The refractive index dispersion for all films was modeled using the Cauchy model, with parameters showing high dependence on the thickness values.The refractive index at high frequency, as calculated using the Cauchy model, was observed to decrease with increasing film thickness, ranging from 1.87 at 106nm to 1.63 at 426nm. Similar values were obtained by fitting the optical refractive index data with the Wemple-DiDomenico relation. Additionally, the UV sensing performance of the films was evaluated against UV light of a single wavelength (365 nm) at applied voltages of 10, 20, and 30V. The rise and decay times were measured, with the film thickness of 426 nm exhibiting the shortest rise and decay times at a specific applied voltage.

Exploring novel magnetic behaviors in cobalt-doped magnetite synthesized by plasma arc discharge method

Magnetite, a naturally occurring iron oxide, has been widely studied due to its potential applications in various fields. Doping magnetite with foreign ions can significantly alter its structural and magnetic properties. This study aimed to investigate the effects of Co2+ ion doping on the structural and magnetic properties of magnetite. The work introduces cobalt-substituted iron ferrites synthesized using a novel plasma arc discharge (PAD) method and systematically explores how cobalt content affects magnetic properties, aiming to optimize the material for enhanced performance. A series of CoxFe1-xFe2O4 (x=0, 0.1, 0.2, 0.3, and 0.5) ferrites with varying Co2+ concentrations (x=0, 0.1, 0.2, 0.3, and 0.5) were synthesized using a PAD method. The synthesized materials were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Magnetic properties were evaluated through magnetic hysteresis loops and permeability spectra. XRD analysis confirmed the formation of a nanostructured spinel-type oxide in all samples. FESEM images revealed ultra-fine particles with a homogeneous composition and narrow size distribution. The optimal combination of magnetic properties was achieved at a Co2+ concentration of x=0.1, which exhibited a high saturation magnetization, low coercivity, moderate effective anisotropy constant, and a relatively high magnetic permeability at 5 MHz. The results demonstrate that Co2+ ion doping can effectively tailor the structural and magnetic properties of magnetite. The optimized composition (x=0.1) offers promising potential for applications requiring a balance of high magnetization and low coercivity.

Enhanced gas sensing performance of ZnO and Pt-doped ZnO nanostructured films by chemical spray pyrolysis

This study focuses on the preparation and characterization of zinc oxide (ZO) and platinum-doped zinc oxide (Pt-ZO) nanostructured thin films using the chemical spray pyrolysis technique. Structural and morphological properties of the films were investigated via X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). To understand the semiconducting nature and carrier dynamics, UV-Vis spectroscopy, electrical conductivity measurements, and a static gas sensing system were employed. The films exhibited crystallization in the hexagonal wurtzite structure with a preferred orientation along the (002) plane. FESEM images revealed the presence of small bright particles, particularly abundant in the 5 wt% Pt-doped ZO thin film, indicating the presence of platinum catalysts. Electrical conductivity measurements confirmed the semiconducting nature of the films. Optical parameters such as band gap and absorption index were obtained from UV-Vis spectroscopy. Gas sensing performance towards liquefied petroleum gas (LPG) showed that the 5 wt% Pt-doped ZO thin film exhibited a high response (69.9) to a 50 ppm concentration of LPG at 350 °C. The gas response and recovery times were observed to be 8 s and 12 s, respectively. These results are attributed to interactions between LPG molecules and adsorbed oxygen species on the sensor surface. Platinum atoms on the oxide surface facilitate the formation of oxygen vacancies and the dissociation of oxygen molecules at low temperatures, leading to increased adsorption and reaction with LPG molecules. This results in significant changes in the sensor's resistance, thereby amplifying the sensor response. The findings demonstrate the potential of Pt-doped ZO thin films for practical gas sensing applications.