X-ray Diffraction Diffractograms Research Articles

Silver nanoparticles from ascorbic acid: Biosynthesis, characterization, in vitro safety profile, antimicrobial activity and phytotoxicity

Skin lesions are caused by the interruption of their functions, causing several possibilities of injury, and affecting the patient's quality of life. Thus, an effective alternative to this problem is the application of metallic nanoparticles with considerable antimicrobial activity, such as silver nanoparticles (AgNPs). In this context, the present study aims to synthesize and characterize AgNPs from l-ascorbic acid (AA) for a possible cutaneous tissue engineering, evaluating the in vitro safety profile (VERO cells line), antimicrobial activity (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa strains), genotoxicity effect and phytotoxicity (Lactuca sativa and Beta vulgaris L. seeds). The novelty of the present study consists of applying green silver nanoparticles for potential application in skin lesions, followed by the study of toxicity in seeds (phytotoxicity), cells (cytotoxicity and genotoxicity with the in vitro safety profile), and antimicrobial activity. X-ray diffraction (XRD), N2 porosimetry, Field Emission Gun – Scanning Electron Microscope (FEG-SEM), zeta potential (ZP), Scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), and Fourier-transform infrared spectroscopy (FT-IR) were used to evaluate the morphological, structural, and textural properties of the AgNPs. XRD diffractogram showed characteristic peaks of a face-centered cubic crystal structure at 38.06° (111); 44.26° (200); 64.45° (220); 77.37° (311) and 81.34° (200). FEG-SEM micrography indicated a predominantly spherical morphology and uniformly distributed structure with an average size of 58.4 ± 19 nm. Moreover, AgNPs demonstrated functional groups characteristics of the reducing agent and the metallic precursor, such as the –OH, –CH, –CO, - CC, and Ag–O stretchings. AgNPs showed SBET = 0.3 ± 0.0085 m2 g−1, Dp = 16.2 ± 10.2 nm, Vp = 0.0008 ± 0.0002 cm³ g−1 and ZP = −27.6 ± 1.9 mV with hysteresis type H1 and mesoporous characteristics. EDX analysis indicated the presence of AgNPs (72.34 wt% and 10.46 wt% silver and oxygen respectively) indicating the effectiveness of the biosynthesis process. For the in vitro safety profile, AgNPs did not show cytotoxicity on VERO cells ranging from 0.5 to 150 μg mL−1 with a good gemoprotection. The minimum inhibitory concentration (MIC) showed that AgNPs have an inhibition of 312 μg mL−1 and 156 μg mL−1 on Gram-positive and Gram-negative strains, respectively. The phytotoxicity showed that only high concentrations (50 and 100 μg mL−1) of AgNPs interfered with seed growth. Therefore, AgNPs biosynthesized from l-ascorbic acid (AA) have potential applications as antimicrobial dressings and are biocompatible for application in skin lesions.

The potential of calcium oxide nanocatalyst from chicken eggshells for biodiesel production using chicken fat waste

This research aims to synthesize biodiesel using raw materials from chicken fat waste and a catalyst from eggshells (EGS). The eggshells used as a catalyst were calcined (EGS_calcined) and uncalcined (EGS_uncalcined). The calcination process was carried out at a temperature of 900 °C with a heating rate of 5 °C/minute under static air conditions for 24 h. The X-ray Diffraction diffractogram showed that the calcination process has successfully converted the calcium carbonate compound in the eggshell into calcium oxide. The particle sizes of EGS_uncalcined and EGS_calcined catalysts were 509.2 nm and 2.9 nm, respectively. Chicken fat transesterification reaction conditions were optimized to increase biodiesel yield, including variations in EGS catalyst mass (1–3 % of chicken fat extract (oil) weight), oil and methanol mole ratio (1:5–1:30), temperature (55–75 °C), and reaction time (30–180 min). The EGS catalyst mass conditions, oil and methanol mole ratio, temperature, and reaction time that produced the highest yield (93 %) were 1.5 % (w/w oil), 1:10, 65 °C, and 120 min, respectively. Research showed that the calcined EGS_catalyst performs better than the uncalcined EGS_catalyst.

Degradation of Methyl Red (MR) dye via fabricated Y2O3–MgO/g-C3N4 nanostructures: Modification of band gap and photocatalysis under visible light

In this study, graphitic carbon nitride (g-C3N4) composites with metal oxide nanoparticles (Y2O3, MgO) and their combination (CN, YCN, MCN and YMCN) were synthesized by an ultrasonic technique and were then characterized by different tools such as UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis and X-ray photoelectron spectroscopy (XPS). From the XRD diffractograms of the YMCN ternary composite, the g-C3N4, cubic MgO and Y2O3 structural phases were identified. The morphology of the as prepared nanostructure from the SEM analysis revealed the dispersion of the metal oxides nanoparticles with the graphitic sheets and the presence of the corresponding elements were confirmed by the EDX and XPS data. The FT–IR bands confirmed the bonding of the metal oxides to the nitride host as indicated by the characteristic modes. A reduction of the band gap energies was confirmed by the UV–Vis to indicate its visible light possible photoactivity. Accordingly, its visible light driven photocatalytic performance was assessed for methyl red degradation. The degradation competence was highest for the ternary composite YMCN due to the coupling of the semiconductors which increases the absorption and the charge carriers’ separation as well. The kinetics of degradation was best described by pseudo-first-order, and the most active species were the holes and the hydroxyl radicals. Thus, the YMCN nanocomposite is a visible light-active photocatalyst which can be engaged in the degradation of organic pollutants.

Supported heterogeneous catalyst of the copper oxide nanoparticles and nanozeolite for binary dyes mixture degradation: Machine learning and experimental design

The present work aims to evaluate the photocatalytic activity of an alternative supported nanocatalyst (nANA@CuO-NPs) for a binary dye mixture (Crystal Violet and Methylene Blue, labeled CV:MB) under visible light and study to propose a model to predict the reaction pathway for the process. An experimental design (Central Composite Rotational Design with 3 factors and 2 levels – CCRD 23) was proposed to evaluate the ideal condition of the CV/MB photodegradation and four machine learning algorithms (Decision Tree, Random Forest, Xtreme Gradient Boosting and Artificial Neural Network-Multilayer Perceptron) were used to predict the main degradation products. The supported nanocatalyst was characterized by X-ray diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, N2 porosimetry, Diffuse Reflectance Spectroscopy (DRS), Field Emission Gun – Scanning Electron Microscope (FEG-SEM), Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), zeta potential (ZP) and zero charge point (pHZCP). XRD diffractogram of the nANA@CuO-NPs showed the tenorite and analcime phases with crystallite size and microstrain ranging from 0.319 to 22.35 nm and 6.48–454 × 10−3. ATR-FTIR spectra indicated the presence of functional groups characteristic of copper oxide nanoparticles (CuO-NPs) and nanozeolite analcime (nANA) on the supported catalyst, confirming the impregnation method. SEM micrographs indicated a heterogeneous surface with clusters (CuO-NPs and nANA@CuO-NPs) and homogenous surface for nANA, while the EDX showed the nANA with Si/Al < 2 (low-silica nanozeolite) and nANA@CuO-NPs with the presence in the elemental composition of the catalytic support (nANA) and the photoactive phase (CuO-NPs). Supported nanocatalyst showed physio-chemical stability due to the electrostatic interactions (ZP = 51.5 ± 0.5 mV) and band gap energy (Eg) of the 1.67 eV allowing its applicability under visible radiation. XGB algorithm resulted in the best predictive model (R2 equals 0.8106 and 0.9880 for training and testing, RMSE < 6.0), confirming the obtention of carbon dioxide (m/z = 44), water (m/z = 18) and low-molar mass compounds at the final of the binary dye mixture degradation reaction. The ideal condition for the by CCRD 23 for the degradation of the dye mixture was [CV:MB] = 135 mg/L, [nANA@CuO-NPs] = 1 g/L and pH = 7 with 82.84 % (k = 0.0089 min−1). Therefore, the synthesized nanocatalyst proved its good photocatalytic activity toward a cationic dye mixture of CV and MB dyes. Furthermore, this work confirms the potentiality of machine learning algorithms to develop predictive models for the elucidation of the degradation reaction pathway of organic dyes.

Characterization and Drug Release Properties of Curcumin Loaded Native and Nano‐Sized Starches of Pigeon Pea (Cajanus cajan) and Bambara Nut (Vigna subterranean)

AbstractStarches from underutilized sources such as Bambara nut (BAM) and pigeon pea (PP) can serve as new sources of starch. Starch nanoparticles (SNP) of BAM (BAMnp) and PP (PPnp) are prepared by nanoprecipitation. The physicochemical and pasting properties of the native and SNP are evaluated. The scanning electron microscopy, fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), drug loading, and release studies of curcumin‐loaded starches and SNP are carried out. The flow, swelling, and solubility of the native starches improve with nanoparticle fabrication. Setback viscosities of the starches are in the order PPnp &lt; BAMnp &lt; PP &lt; BAM. The integrity of the starch granules is maintained after modification. The FTIR of loaded starches shows no interaction between the entities. Reduction in crystallinity of the SNP is observed in the XRD diffractogram. The drug loading efficiency of BAM, PP, BAMnp, and PPnp are 48.55 ± 0.11, 49.00 ± 0.11, 55.44 ± 0.40, and 54.72 ± 0.11, respectively. The drug release is improved when curcumin is loaded on the SNP. The release after 6 h is 33%, 25%, and 2% for BAMnp, PPnp, and pure curcumin, respectively. The properties of the SNP showed that they are potential candidates for the delivery of curcumin, a poorly water soluble drug.

In‐situ Synthesis of Highly Potent Antibacterial Copper‐Based MOFs/Sodium Alginate Composite Beads

AbstractThe present study reports an environmentally friendly in‐situ synthesis of novel antibacterial copper‐based MOFs within the hydrogel network of sodium alginate. Two different copper‐based MOF/sodium alginate composite beads were prepared via the post‐treatment of copper‐ion‐crosslinked alginate hydrogels with two different ligand solutions, namely, tartaric acid and oxalic acid, at 100 °C for 24 h. The structural, thermal, and morphological properties of the prepared samples were investigated using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), and their antibacterial activities against gram‐positive (Staphylococcus aureus and Bacillus) and gram‐negative (Escherichia coli and Pseudomonas aeruginosa) strains were examined using the conventional disc diffusion method. The results demonstrated the success of the in‐situ synthesis of two distinct copper‐based MOFs with FTIR spectra, confirming the existence of characteristic bands of the ligands complexed to the sodium alginate matrix. Moreover, the XRD diffractograms revealed the formation of two distinct crystalline structures with well‐defined morphologies observed in the SEM images. In addition, thermal analysis showed that the prepared composite beads had enhanced thermal stability compared to the copper‐ion‐crosslinked alginate beads. Antibacterial testing revealed the strong capacity of the copper‐based MOFs/sodium alginate composite beads to deactivate the growth of all the bacterial strains used, with a minimum inhibition zone of 23 mm, which highlights the potential of the synthesized materials as highly potent antibacterial agents.

Optimization and characterization of sustainable geopolymer mortars based on palygorskite clay, water glass, and sodium hydroxide

Abstract The synthesis of ambient-cured sustainable geopolymer mortars (GMs) was studied throughout this work. To reduce carbon dioxide emissions, new materials must be used in the production of sustainable concrete and mortars. Many types of binders are used in the synthesis of GM and concrete (GPC), especially clay minerals. These clay minerals are considered sources of alumina and silica in GM and concrete. The geopolymerization process relies on the alkaline solution activating the alumino-silicate to produce geopolymer gel products. The palygorskite (PA) clay mineral, sodium hydroxide (NaOH), and sodium silicates (Na2SiO3) were chosen as a binder (solid material) and alkaline activator solution to synthesize GM at ambient temperature. PA was thermally treated at 550, 650, 700, and 750°C, respectively, to convert into high-reactive PA (HRP) HRP550, HRP650, HRP700, and HRP750, respectively. The characteristics of PA clay, HRP powders, and HRP-based GM were evaluated using compressive strength (CS) testing, X-ray fluorescence analysis, carbon footprint analysis, X-ray diffraction (XRD) diffractograms, Fourier transform infrared spectroscopy (FTIR) spectroscopy, scanning electron microscopy (SEM) images, and energy-dispersive X-ray spectroscopy (EDS) analysis. The maximum CS of 25.1 MPa was acquired for geopolymer synthesis utilizing HRP700-based GM cured at 30°C for 28 days. FTIR spectroscopy demonstrated that HRP-based GM showed the presence of Si–O, Al–O, and O–C–O bonds stretching vibrations in the alumino-silicate network. The results showed that the CO2 emissions had a reduction in the HRP-based GM compared with the reference mix of ordinary Portland cement mortar (OPM). The percentage of reductions was 14.1, 13.7, 13.1, and 12.4 for HRP550, HRP650, HRP700, and HRP750, respectively, compared with the OPM mixture. SEM images/EDS analysis and XRD diffractograms confirmed the presence of sodium alumino-silicate hydrates, magnesium silicate hydrate, and calcium silicate hydrate gels with high quantities particularly in the HRP700-based GM than that in HRP550, HRP650, and HRP750, respectively. The results indicate the suitability of HRP calcined at 700°C (HRP700) in the synthesis of the GM.

Photodegradation of Rhodamine B by CeO2-CuO Binary Composite Nanoparticles Synthesized by Self-Combustion Method

A novel binary composite CeO2-CuO has been synthesized via self-combustion method employing cerium and copper nitrates, and glycine as fuel, and was investigated as photocatalyst to test the photodegradation of Rhodamine B (RhB) dye with visible light. The nanocomposite has been characterized by thermogravimetric analysis (TGA) to establish the temperature of calcination, X-ray diffraction (XRD) structural and morphologic analysis, scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), which enables the chemical characterization/elemental analysis of materials, the photoluminescence (PL), UV-Vis Diffuse reflectance spectroscopy (UV-Vis DRS), measurement of specific surface (SBET ) by N2 adsorption and temperature programmed reduction (TPR) analysis. The XRD diffractogram shows that the composite is majorly composed of 65.2% CeO2 and 34.8 % CuO. The nanoscaled-tested samples have an average particle size of 40 to 65 nm. The energy gap of the material as synthesized was 2.05 eV. The TPR curves show 2 peaks of hydrogen consumption in the sample, corresponding to the decrease (reduction) of CuO particles caused by their interaction with CeO2.The results of the photocatalytic tests show 28% conversion in the photodegradation of RhB organic pollutant during 180 min under visible light. The CeO2- CuO material could be reused for treatment of wastewater during several cycles, which demonstrates its stability for the process.

A Simple Synthesis and Microstructure Analysis of Human Peptide LL-37@Gold Nanoparticles (Known as LL-37@AuNPs) Conjugates as Antimicrobials and Substances for Wound Healing.

The basis of the present study is a straightforward method involving fewer chemical species for conjugating gold nanoparticles (AuNPs) with the antimicrobial peptide LL-37 designated as LL-37@AuNPs. Investigating the microstructure characteristics of the resulting materials and their potential as antibacterial and wound-healing substances are the main objectives of this study. Zeta (ζ) potential, Fourier transform infrared (FTIR), X-ray diffraction (XRD), field effect scanning electron microscopy (FE-SEM), energy dispersive X-ray diffraction (EDS), transmission electron microscopy (TEM), and UV-Vis spectrophotometry were used to analyze the physico-chemical properties of LL-37@AuNPs. The magnitude of LL-37's zeta potential and the LL-37@AuNPs show that the specimens are electrically stable and resistant to flocculation and coagulation. The surface plasmon resonance (RPS) of AuNPs, which is positioned at a wavelength of about 531 nm, was found to be unaffected by the presence of the LL-37 antimicrobial peptide. The FTIR data show the functional group characteristics of the LL-37@AuNPs vibration bands, and the XRD diffractogram confirms the formation of the LL-37@AuNPs conjugate nanocomposite. Based on FE-SEM and TEM data, the bulk of AuNPs were found to have a circular shape, with an average size of about 22.88 ± 8.21 nm. It was discovered that the LL-37@AuNPs had a good ability to inhibit S. aureus from growing. The wound-healing percentage reached 85% on day 12 of the trial, significantly greater than the results of the negative controls. LL-37@AuNPs(4) is the sample that had the highest percentage of wound healing between days 3 and 12. Moreover, sample LL-37@AuNPs(4) contains 0.45 µL of LL-37, whereas sample LL-37@AuNPs(2) contains 0.22 µL of LL-37. The faster wound-healing rate in LL-37@AuNPs(4) was believed to be due to a higher concentration of LL-37, which was able to stop S. aureus from developing while suppressing the inflammation surrounding the wound. The study's findings reveal that LL-37@AuNPs might be made using a straightforward process, making them a powerful antibacterial and therapeutic substance. However, before this discovery is applied in the field of medicine, a more thorough investigation is necessary.

Swift Removal of the Heavy Metals Cadmium and Lead from an Aqueous Solution by a CAN-Zeolite Synthesized from Natural Clay

CAN-zeolite was synthesized with a high purity from natural kaolinite via alkali fusion by hydrothermal treatment at a pressure of 1 kbar H2O. It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy and nitrogen adsorption at 77 K. The results show that after AK hydrothermal treatment (under specific conditions), the SBET increases from 5.8 m2g−1 to 30.07 m2g−1 which is six times greater. The AK which was a non-porous or macroporous solid (the nitrogen adsorption/desorption of AK is of type II) became mesoporous (N2 adsorption–desorption isotherms exhibit typical hysteresis of type IV) with a pore size of 5.9 Å. XRD of AK shows the presence of quartz (Q) as impurities, and illite and kaolinite as major fractions; after hydrothermal treatment, the XRD diffractogram shows only fine pics related to CAN-zeolite (with a good crystallinity), confirming the success of the synthesized process. These results suggest that the synthesized CAN-zeolite has the potential to be tested in the removal of heavy metals from waste water as part of a remediation process. Batch reactors were used to evaluate the adsorption isotherms and kinetic studies of heavy metals, cadmium, and lead, by natural kaolinite clay (AK) and synthesized cancrinite zeolite (CAN-zeolite). The results show that the adsorption kinetics of the bivalent heavy metals cadmium and lead are extremely fast with either AK or CAN-zeolite. Equilibrium was reached within 2 min. Adsorption isotherms show that the synthesized CAN-zeolite has a higher adsorption capacity; the retention capacity of lead and cadmium was three times greater than that presented by the natural clay mineral. According to the findings, CAN-zeolite has a higher affinity for PbII (192 mg/g) compared to CdII (68 mg/g). The negative reactive surface sites interacting with these cationic heavy metals resulted in a higher amount of heavy metals adsorption than the cation exchange capacity (CEC). The adsorption information was analyzed using the Langmuir and Freundlich equations. The Langmuir model provided a good fit to the equilibrium data, indicating a monolayer adsorption mechanism.

Structural and antibacterial evaluation of copper, silver, and bimetallic silver/copper nanoalloys synthesized in chitosan biopolymer

Silver nanoparticles (AgNP) have been used as an alternative to microbial resistance. Nevertheless, AgNP high cost and moderate toxicity to humans limit their use. Copper nanoparticles (CuNP) emerge as an alternative, but their fast oxidation hampers large-scale use. In this scenario, this work propose the synthesis optimization of Ag, Cu, and bimetallic Ag/Cu nanoparticles in a chitosan aqueous solution using factorial design statistics. UV-Vis spectroscopy, zetasizer, and transmission electron microscopy (TEM) measurements demonstrated that the optimized synthetic procedure formed highly stable and monodisperse nanoparticles. X-ray diffraction (XRD) confirmed the nanoparticle's crystalline structure and indicated the presence of an oxide state in CuNP. In addition, X-ray photoelectron spectroscopy (XPS) measurements confirmed that this oxidation occurs at the CuNP surface level. Considering Ag/CuNP, Rietveld refinement of XRD diffractogram demonstrates the formation of an unusual and novel Ag/Cu nanoalloy structure, which was possible due to the metallic ion chelation to chitosan nitrogens before and during nanoparticle growth. In addition, silver presence in the nanoalloy inhibited copper oxidation through an electromigration mechanism. Comparing CuNP, AgNP, and Ag/CuNP, it was possible to reveal the microbicide abilities of the nanoparticles against both Gram-positive and Gram-negative bacteria, emphasizing that the Ag/Cu nanoalloy is a viable option due its high antimicrobial activity and colloidal stability. Therefore, the rational design allowed the synthesis of highly stable NP in the chitosan matrix which exhibited strong antimicrobial activity, indicating that Ag/Cu nanoalloys can act as the next-generation nanomaterials for pathogenic microorganism inactivation.

STRUCTURAL INVESTIGATION OF HETERO-STRUCTURED CORE-SHELL SILVER-SILICA HYBRID AS A POTENTIAL AGRO-SENSOR MATERIAL

Investigation into the novel synthesis and structural properties of Heterostructured core shell Silver-Silica (AgSiO2) Nanohybrid is reported herein, for possible utilization as humidity sensing material in Agricultural post-harvest humidity monitoring system and greenhouse farming. The Heterostructured nanoparticles (Ag and SiO2) were synthesized via a chemical reduction method. Structural characterizations were done using X-ray Diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM), Scanning Electron Microscopy (SEM), UV-Visible spectroscopy, Energy Dispersive X-ray (EDX) spectroscopy and N2 adsorption-desorption techniques. The XRD diffractogram of Ag-SiO2 showed distinct peaks at 2? values of 390, 430, 660 and 790 which was corroborated by the SEM and HRTEM results. EDX convincingly confirmed Ag and SiO2 incorporation into the Ag-SiO2 nanocomposite hetero-structure at 16.7 % and 83.3 % respectively. A Surface Plasmon Resonance absorption peak of 421 nm of Ag was revealed by UV-Visible spectroscopic analysis. An effective and relatively narrow pore size distributions of 3 – 8 nm was revealed by N2 adsorption-desorption for the Ag-SiO2 Nanocomposite. Overall, these properties are promising for effective use as humidity sensing material.

Hydrazine-Fueled Solution Combustion Method: Fuel/Oxidizer Ratio Effects on Photocatalytic Performance of Bismuth Oxide

Bismuth oxide nanoparticles were synthesized through the solution combustion method with a variation of fuel: oxidizer (hydrazine: bismuth nitrate) ratios (ϕ) of ϕ&lt;1, ϕ=1 (stoichiometrically balanced) and ϕ&gt; 1. Bismuth oxide nanoparticles were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and UV-Visible Diffuse Reflectance Spectroscopy (UV-DRS). The FTIR spectra obtained implies that the bismuth oxide nanoparticles of the three ratios contain Bi-O-Bi and Bi-O groups indicating its successful formation. XRD diffractogram suggests that the synthesized bismuth oxide nanoparticles form the α-Bi2O3 crystalline phase for ϕ&lt;1 and ϕ&gt;1; meanwhile a mixture of α-/β- Bi2O3 phases for ϕ=1. The SEM image illustrates that bismuth oxide nanoparticles form pebble shapes with the ratios in the order of increasing particle sizes of ϕ&gt;1, ϕ=1, and ϕ&lt;1. The UV-DRS results show that the bismuth oxide with ϕ&lt;1, ϕ=1, and ϕ&gt;1 have respective band gap energies of 2.76 eV, 2.72 eV, and 2.78 eV. The evaluation of the photocatalytic activity of the three bismuth oxide samples shows bismuth oxide with ϕ=1 has the highest photocatalytic activity in remazol black B and methyl orange dyes with rate constants 6.744 x 10-5 s-1 and 7.369 x 10-5 s-1, respectively. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Multiferroic behavior of room temperature bismuth ferrite with tailored calcination temperature

One of the few materials that is multiferroic (antiferromagnetic and ferroelectric) is bismuth ferrite. In this study, we used the sol-gel method to create multiferroic bismuth ferrite and examined its structural and optical characteristics. The annealing temperature used to create bismuth ferrite was 600°C. The rhombohedral crystal structure was revealed by X-ray diffraction (XRD) investigation. The XRD diffractogram data examines the phase and planes of orientation for the synthesized materials. The crystalline size for the peak was determined using the Scherrer equation. Analysis using the Fourier transform infrared (FTIR) confirmed the existence of M-O octahedral and tetrahedral coordinates of the M-O bonds formed. The Fourier transform infrared in the wavenumber range of 500–850 cm−1 has been used to study the vibrational modes of the octahedral and tetrahedral metal complexes in the sample. Studies using a FESEM show that the synthesized nanocomposite has morphological characteristics, including interconnected agglomerates with spherical, irregular, or non-uniform elongated forms. By increasing the loading percentage of bismuth ferrite, the composite remnant magnetization (Mr) and saturation magnetization (Ms) values were discovered to be 0.43701 emu/g and 0.1940 emu/g, respectively. A frequency range of 10 Hz to 106 Hz was used to study the dielectric measurement of the nanocomposites. In the temperature range of 310 to 525 K, the AC conductivity has been measured, and it has been discovered that conductivity decreases as temperature rises. A temperature increase results in a reduction in the dielectric constant and dielectric loss. The initial data imply that the nanocomposite is a possible contender for use in capacitors with high dielectric constants. The composite will be useful for usage in hard disc components due to its magnetic characteristics, which is significant.

Biosynthesis of Graphene Oxide Nanoparticles from Coconut Fronds

To address the ecofriendly approach for the nano graphene oxide (nGO) synthesis, “Wealth from waste” idea utilized in this study. The synthesis process involves the controlled reduction and manipulation of nGO sheets to achieve nano-scale dimensions, resulting in nGO with improved structural integrity and enhanced surface area. Characterization of the synthesized nGO is conducted using advanced analytical tools, including Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), UV-Visible spectroscopy (UV-VIS) and Particle Size Analyser (PSA). The PSA analysis revealed, a predominantly monodisperse distribution with a peak size of approximately 314 nanometers with indicative of good dispersion uniformity. The UV-Visible spectroscopy displayed a significant absorption peak at 234 nanometers, elucidating the material’s optical characteristics. TEM images unveiled the structural features such as wrinkles, folds and nanoscale dimensions. The XRD diffractogram suggested the presence of both GO and rGO phases with unique intensity peaks at 10.33° and 32.35° shown the interlayer spacing of 3.72 and 1.11 nm respectively. These analyses provide valuable insights into the morphology, size and crystallinity present in the nGO, aiding in its structural elucidation. These findings affirm the successful conversion of coconut fronds waste into GO nanoparticles and open avenues for sustainable nanomaterial production. The unique properties of GO are utilized for water purification, oil spill cleanup, energy storage, sensors, composite materials, photodetectors, anticorrosive coatings, and so on. The biosynthesis of nano graphene oxide particles offers exciting opportunities for the development of next-generation materials with enhanced performance characteristics.

Characterization and antimicrobial evaluation of biomimetically synthesized silver nanoparticles using aqueous leaf extract of Morinda lucida Benth. (Rubiaceae)

Silver nanoparticles (AgNPs) are silver atom masses that are attracting widespread interest due to their diverse applications, particularly their activity as antimicrobial agents. Physico-chemical methods of AgNP synthesis are associated with high costs, high temperatures and toxic byproducts. Thus, the plant mediated pathway represents a better option. The indigenous medicinal plant Morinda lucida was employed in the fabrication of AgNPs. The nanoparticles were characterized using different analytical techniques and also evaluated for their antimicrobial potential. Phytochemical screening of the plant was also carried out. For the synthesis, 10 ml of aqueous M. lucida leaf extract was added to 90 ml of freshly prepared 3 mM silver nitrate (AgNO3) solution in a flask. The mixture was allowed to stand at ambient temperature, in a dark cupboard for 48 hours. Positive AgNP synthesis, indicated by a colour change from red to brown was further validated by UV-vis spectroscopy wherein an absorption peak at 460.51 nm was recorded. The utilitarian aspects of the particles were further characterized using scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The SEM images showed that particles were round to irregular in shape. Amide, amine, alkene and alkynes were the most occurring functional groups from the FTIR spectra. Quantitative phytochemical analysis revealed the presence of flavonoids, terpenoids, phenols, reducing sugars and alkaloids in varying amounts, which play a significant role in the synthesis and stabilization of the AgNPs. The XRD diffractogram of AgNPs showed two peaks at 45.53° and 77.17° that correspond to miller indices of (200) and (311) respectively and an average crystalline size of 62.60 nm obtained using the Debye-Scherrer’s formula. The DLS result indicated a Z–average size of 235.1 nm and a polydispersity index (PDI) of 0.4. EDX analysis showed that elemental silver (Ag) had the highest atomic concentration of 64.50 %. Using the agar well diffusion assay, the nanoparticles exhibited antimicrobial activity against P. aeruginosa (bacteria) and A. flavus (fungi). It can be concluded that M. lucida is capable of synthesizing stable, small-sized AgNPs with antimicrobial potential.

Elucidating the Effect of Dry-Room Atmospheres on the Performance of Sulfidic Sheet-Type Separators for All-Solid-State Batteries

Electrifying the automotive sector requires energy storage systems with high energy and power density, intrinsic safety, and long durability.[1] Lithium-based all-solid-state batteries (ASSBs) are considered promising next-generation energy storage devices, as they possibly meet these requirements by replacing organic liquid electrolytes with non-flammable solid electrolytes (SEs) and by enabling the application of novel high energy density anode concepts.[2, 3] Among the SE material classes being pursued for use in ASSBs, sulfidic systems are considered particularly advantageous, as they possess high ionic conductivities and low Young’s moduli, enabling easier processing and densification compared to oxidic systems.[4] However, a rarely addressed key bottleneck to commercializing ASSBs with sulfidic SEs is the requirement on the environmental conditions during handling, processing, and assembly of the battery components, which will be dictated by the instability of sulfidic SEs towards humidity.[5] On the laboratory scale, this issue has been avoided by handling the sulfidic ASSB materials, components, and cells in argon-filled gloveboxes, but for the commercial production of ASSBs their manufacturing would preferably be done in a dry-room atmosphere.[6] However, very few studies exist that examine whether the dew points of typical dry-rooms are sufficient to handle and/or store ASSB components based on sulfidic SEs.[7,8] In this contribution, we will examine the dry-room compatibility of scalable sulfidic composite (Li6PS5Cl/HNBR) sheet-type separators,[9] investigating the influence of the exposure time to a dry-room atmosphere with a dew point of -48°C on the stability of the SE and on its electrochemical properties. Using X-ray diffraction (XRD) combined with Rietveld refinement and scanning electron microscopy (SEM), the influence on the morphology and the formation of degradation products upon reaction with the small concentration of water in a dry-room will be investigated. The results show that only long exposure times (> 96 h) lead to a significant hydrolysis-induced change in the XRD diffractograms, which indicates the formation of degradation products such as Li2S, LiCl, and Li3PO4.By means of potential electrochemical impedance spectroscopy (PEIS), the impact of different exposure times on the Li+-ion conductivity of the sheet-type Li6PS5Cl/HNBR separators and the activation energy for the Li+-ion transport are investigated (cf. figure 1). While short exposure times (< 12 h) have a minor influence on the Li+-ion conductivity (lowering it from 0.3 mS/cm to 0.25 mS/cm) and a negligible effect on the activation energy, longer exposure times (> 48 h) lead to a ≈ 10-fold loss of ionic conductivity (to ≈ 0.03 mS/cm) and a drastic increase in activation energy.Besides measuring the loss of ionic conductivity, the separator sheets are also used for assembling LiNi0.6Co0.2Mn0.2O2|LiIn half-cells, which are investigated using galvanostatic cycling. An analysis of the capacity profiles shows that an increased exposure of the separators to the dry-room atmosphere leads to a significant IR-drop, to lower initial discharge capacity, and enhanced capacity fading over several charge/discharge cycles. Further insights into these degradation phenomena will be gained by analyzing the dQ/dV plots, the mean (dis)charge voltage, and the full-cell impedance of the half-cells.Based on our findings, it can be concluded that moderate exposure times in a dry-room of up to 12 h have only a negligible effect on the chemical integrity and performance of sulfidic Li6PS5Cl/HNBR separators sheets. This opens the route of defining viable storage and processing times of sulfidic ASSBs cell components in industrial dry-room environments.[1] Y. Ding, Z. P. Cano, A. Yu, J. Lu, Z. Chen, Electrochemical Energy Reviews, 2, 1 – 28, (2019).[2] J. Janek and W. G. Zeier, Nature Energy, 1, 16141, (2016).[3] P. Oh, J. Yun, J. H. Choi, K. S. Saqib, T. J. Embleton, S. Park, C. Lee, J. Ali, K. Ko, J. Cho, Angew. Chem. Int. Ed., 61, e202201249, (2022).[4] A. Sakuda, A. Hayashi, M. Tatsumisago, Scientific Reports, 3, 2261, (2013).[5] H. Muramatsu, A. Hayashi, T. Ohtomo, S. Hama, M. Tatsumisago, Solid State Ionics, 182, 116 – 119, (2011).[6] D. H. S. Tan, Y. S. Meng, J. Jang, Joule, 6, 1755-1769, (2022).[7] Y.-T. Chen, M. A. T. Marple, D. H. S. Tan, S.-Y. Ham, B. Sayahpour, W.-K. Li, H. Yang, J. B. Lee, H. J. Hah, E. A. Wu, J.M. Doux, J. Jang, P. Ridley, A. Cronk, G. Deysher, Z. Chen, Y. S. Meng, J. Mater. Chem. A , 10, 7155-7164, (2022).[8] C. Singer, H.-C. Töpper, T. Kutsch, R. Schuster, R. Koerver, R. Daub, ACS Appl. Mater. Interfaces, 14, 24245–24254, (2022).[9] C. Sedlmeier, T. Kutsch, R. Schuster, L. Hartmann, R. Bublitz, M. Tominac, M. Bohn, H. A. Gasteiger, J. Electrochem. Soc., 169, 070508, (2022). Figure 1

Physiochemical Characterization of Ethiopian Mined Kaolin Clay through Beneficiation Process

Kaolin mineral is a commercially solid powder with a comparatively low level of purity and is regularly used for a variety of applications, including filler, paints, ceramics, adsorbents, and paper. In Ethiopia, the kaolin clay mineral is significant for financial growth as the raw material used in the industry sector. However, slight consideration was given to the chemical, physical, mineralogical, and morphological properties of kaolin. In this study, the property of kaolin is investigated by using advanced instruments such as X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTA). Based on the XRF test, the main component of kaolin clay contains SiO2 (58.73%), Al2O3 (24.35%), K2O (5.36%), and other impurities, including Fe2O3 (2.06%) and TiO2 (0.13%). The FTIR spectra displayed the functional groups Si-O, Al-OH, Al-O, and Si-O-Al. The XRD diffractogram identified kaolin clay as the main mineral phase in the existence of quartz, halloysite, and chlorite.

Synthesis and structural characterization of nanocomposites ZnO/CdO prepared by sol-gel method

The present paper report the formation of ZnO/CdO composites via the Sol-Gel technique. The synthesized sample is dried in air and annealed at 300 °C. The heat-treated sample is powdered and structure characterization of obtained powder composite is investigated through X-ray diffraction (XRD) and Rietveld refinement techniques. The crystal structure, morphology, and composition of the powder composite were analyzed in detail. XRD diffractograms were obtained through X-ray diffraction and the Rietveld refinement method is used to estimate the crystalline phases present in the sample using XRD results. The refinement of the prepared samples was done by Fullprof Suite Software. The analysis of diffractograms gives the crystalline nature and refinement gives the presence of ZnO and CdO phases. XRD data was used to find the size and the crystallite size estimated for ZnO is 38.35 nm, and for CdO is 44.09 nm. Refinement suggests that ZnO is hexagonal with space group P36mc (186), while CdO is cubic with space group Fm-3 m (225). Lattice parameters calculated for ZnO are found to be a = b = 3.250, c = 5.213, α = β = 90°, and γ = 120°, and for CdO lattice parameters are found as a = b = c = 4.694, α = β = γ = 90°. The dislocation density of ZnO and CdO is calculated as 0.001012 m/m3 and 0.00081 m/m3. Lattice strain of composite is calculated by W-H plot and found to be (2.06 ± 0.876614) * 103.The inter-atomic distance and Wyckoff positions are also estimated.

Feasibility study of Phosphor material synthesis process based on Barium halides via hydrothermal technique

Barium halides based was typical host for phosphor material applied as imaging plate for computed radiography application. In this study, the host phosphor materials based on barium halides has been synthesized via hydrothermal technique. The aim of this study is to determine the feasibility of hydrothermal technique to synthesis phosphor materials. Three samples have been prepared for this study. All samples had fix Ba and Br composition but was differentiated by the third composition i. e F, Cl and I. X-ray diffraction (XRD) technique has been used to determine the crystallinity of the prepared samples while optical property was observed using photoluminescence (PL) spectroscopy. The sharp, narrow and high intensity peaks from XRD diffractogram showed that all samples have good crystallinity. The PL spectrum indicated that the emission of all samples corresponds to blue range. This study proved that hydrothermal method was feasible for phosphor materials synthesis process based on barium halides and offered lower temperature with shorter period of heating process which is cost effective for synthesis process.