X-ray Diffraction Patterns Research Articles

Bacterial nanocellulose-based nanopaper activated by β-cyclodextrin/ Salvia officinalis essential oil complexes for shelf life extension of shrimp

Active bacterial nanocellulose (BNC) nanopapers containing Salvia officinalis essential oil (SEO) in free form and encapsulated with β-cyclodextrin (βCD) were prepared, and their effect on the shelf life extension of shrimp was investigated. The GC–MS analysis of the SEO indicated the presence of various active compounds such as Thujone (21.53 %), Ledol (12.51 %) and Eucalyptol (11.28 %) in the essential oil composition. The cytotoxicity of the SEO and SEO-βCD complexes in the L929 cell line was quite low. FTIR analysis revealed new interactions in the nanopapers containing SEO-βCD complexes. Microscopic images showed that SEO-βCD complexation improved the surface morphology of the BNC nanopapers, whereas free SEO had a negative effect. X-ray diffraction patterns of the nanopapers showed higher crystallinity of the SEO-βCD containing nanopapers than that of the SEO-incorporated nanopapers. Moreover, the addition of the SEO-βCD complex improved the thermal properties of the BNC nanopaper. Water contact angle analysis showed higher hydrophobicity of the samples containing free SEO than that of the other samples. Both SEO-βCD and free SEO increased the elongation at break and decreased the tensile strength of the nanopaper. The prepared active films showed a greater antimicrobial effect on L. monocytogenes than on E. coli. The results showed a higher antioxidant capacity of the free SEO-containing nanopapers (58–78 %). The desirable effects of the active nanopapers on shrimp preservation were demonstrated by the results obtained for the microbial load, pH, and volatile nitrogen content of the product. The results demonstrate the potential of the prepared BNC active nanopapers for use in active antioxidant/antimicrobial food packaging.

Ecofriendly synthesis of copper oxide-chitosan nanocomposites and their efficacy as nano-pesticide and nano-fertilizer

Chemical pesticides and fertilizers are a long time threat to human health and environment. One of the prime risks in pest management is the resistance to insecticide applied. There is demand for formulations which are eco-friendly, effective in small amounts, biodegradable and economically viable. The demand for organic formulations and nanomaterials to control the pests of economically important plants is rising every day. Mealy bugs and fruit flies are the major pests and their control has been a serious issue in pest management. The current research work was conducted to synthesize copper oxide nanoparticles (CuO NPs) from Eucalyptus leaves and nanocomposites comprising chitosan through a green way to evaluate the insecticidal efficacy of prepared nanomaterials. The nanomaterials were characterized by Fourier-transform infrared spectroscopy (FT-IR), UV–Visible spectroscopy, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). CuO NPs showed crystalline monoclinic structure in XRD pattern. Different concentrations of nano-pesticides were tested against mealy bugs and fruit flies to find out % mortality and LC50 values. The LC50 values in mealy bugs for extract, CuO NPs, CuO-Chitosan nanocomposites (NCs) and CuO-Chitosan NCs with Cu layer were found to be 10.45 ppm, 6.96 ppm, 4.58 ppm and 3.29 ppm, respectively. Results showed that mortality enhanced with rising pesticides concentration, so plant extract, CuO NPs, CuO-Chitosan NCs and CuO-Chitosan NCs with Cu layer showed 50 %, 70 %, 80 % and 90 % mortality at the highest concentration (10 ppm). The synthesized nanomaterials significantly improved seeds germination, yield and growth parameters in maize whenever used as nano-fertilizers. The results showed that prepared nanomaterials have good insecticidal effects as well as the best fertilizer properties. So, the products having dual application as nano-pesticides and nano-fertilizers have promising future in agriculture.

Impedance spectroscopy and electrical conductivity of 0.7Bi(1−x)NdxFeO3–0.3BaTiO3 ferroelectric ceramics

0.7Bi[Formula: see text]NdxFeO3–0.3BaTiO3 (BNFO–BTO, [Formula: see text], 0.010, 0.020 and 0.050) ceramics were fabricated using the high-temperature solid-state reaction method. The X-ray diffraction (XRD) patterns revealed that the primary phase in these ceramics was pseudocubic. The Scanning Electron Microscopy (SEM) micrographs exhibited dense microstructures throughout all BNFO–BTO ceramics. Furthermore, the temperature dependence of dielectric behaviors and ferroelectric hysteresis loop shapes suggested the occurrence of a relaxor ferroelectric-type phase transition in BNFO–BTO ceramics. Additionally, the frequency dispersion characteristics and remnant polarization were enhanced with increasing substitution of Bi[Formula: see text] by Nd[Formula: see text]. Conducted impedance analysis on 0.7Bi[Formula: see text]NdxFeO3–0.3BaTiO3 ceramics and two dielectric responses of the grain at high frequency and grain boundary at low frequency were illustrated, respectively. The combination of imaginary impedance ([Formula: see text] and imaginary modulus ([Formula: see text] versus log[Formula: see text]f plots revealed that the charge carriers’ motion was not entirely long-range, short-range migration also exists. Through calculations based on Curie–Weiss Law, the relaxation activation energy ([Formula: see text] and conductance activation energy ([Formula: see text] were investigated, confirming that doping Nd[Formula: see text] effectively mitigates the concentration of oxygen vacancies (OVs) and prevents the formation of oxygen vacancies clusters, ultimately suppressing conductivity in BNFO–BTO ceramics.

Examining the dual effect of copper nanoparticles and nitrogen doping on Cu@N-TiO2

Abstract The study of six compositions of Cu@N-TiO2 with different amounts of copper and nitrogen synthesized using a sol–gel method is reported. X-ray diffraction patterns and Raman spectra indicated the formation of a single anatase TiO2 phase in all materials without evidence of secondary phases including copper or nitrogen. Electron microscopy images showed a homogeneous distribution of the copper particles around a TiO2 matrix, just as that the insertion of nitrogen did not have a significant effect on the morphology of the particles. X-ray photoelectron spectroscopy analysis confirmed that nitrogen was inserted in the atomic arrangement of titanium dioxide, while copper was presented mainly as metallic element on the TiO2 surface. Characterization of the optical properties and photoactivity test confirm that band gap strongly depends on the copper and nitrogen content phenomenon attributed to the combined presence of modifiers over the TiO2 surface and the promotion of a plasmonic effect, which displaced the absorption UV bands to higher wavelengths with respect to un-doped TiO2. The catalytic test performed using rhodamine-B as probe molecule, confirm that TiCuN2 and TiCuN3 samples exhibit the best decomposition percentages of 38 and 36 % respectively. Such results confirm the surface plasmon resonance effect associated to Cu particles on the TiO2 as main cause in the increase in current along synthesized samples and the use of cyclic voltammetry technique to identify these effects between 0.0 and 1.5 V.

In situ aluminum doped zinc oxide thin films by pulse electrodeposition for the all-electrodeposited cadmium-free copper indium diselenide solar cells

Pulse electrodeposition was used to produce aluminum doped zinc oxide (AZO) films, which were then used to construct an all-electrodeposited cadmium-free (Cd-free) Copper Indium Diselenide (CISe) solar cell. Aluminum was added into the films during the deposition process by positioning an Aluminum (Al) metal foil into the electrolyte. Energy Dispersive Spectrometry (EDS) elemental mapping confirmed the incorporation of Al into the films. According to X-Ray Diffraction (XRD) patterns, the aluminum doped zinc oxide films have a wurtzite hexagonal crystal structure, only with (002) planes indicating phase purity. The impedance analysis of the annealed device with electrodeposited aluminum doped zinc oxide revealed that it had better charge transfer resistance than the as-deposited device.

Two-dimensional (2D) MoS2-nanosheet (NS) incorporated within electrospun PVA nanofibers: Fabrication and characterization study

In this study, with the help of grinding and sonication, the bulk state of molybdenum disulfide was transformed into a two-dimensional sheet, and composite nanofiber consisting of molybdenum disulfide MoS2/polyvinyl alcohol (PVA) has been successfully developed via electrospinning process. X-ray diffraction (XRD) pattern showed the preferred orientation along the (002) plan of The MoS2 nanosheet. Rietveld refinement was applied to obtain the microstructure parameters of the MoS2. The formation of S-S and Mo-S bonds in MoS2 was confirmed by the Fourier-transform infrared spectroscopy (FTIR). FE-SEM images reveal the surface morphology of MoS2 nanosheets, which typically exhibit a flat and layered structure resembling stacked atomic layers of MoS2 two-dimensional nature.In contrast, the MoS2/PVA fibers display a uniform, interconnected nanofiber network with a distinct random formation. Also, Atomic Force Microscopy (AFM) images show the formation of the uniform MoS2/PVA nanofibers, and the evaluated root mean square (RMS) roughness values for PVA and MoS2/PVA fibers are 250 nm and 277 nm, respectively. To elucidate the elemental composition of the MoS2 nanofibers, Energy Dispersive X-ray Spectroscopy (EDX) analysis was performed, confirming the presence of molybdenum and sulfur in the compound. Finally, diffuse reflectance spectroscopy (DRS) was applied to study the optical properties of the MoS2/PVA composite. In addition, the measurement of the contact angle shows that the surface of the nanofibers is hydrophilic, and the amount of hydrophilicity decreases by adding MoS2 nanosheets.

Photocatalytic removal of some selected antibiotics in polluted water system by graphitic carbon nitride-enhanced vanadium ferrite (VFe2O4@g-C3N4)

Antibiotics such as sulfamethoxazole (SUF), ciprofloxacin (CIP) and erythromycin (ERY) are frequently detected in water systems without being efficiently removed during water treatment. This study synthesized a graphitic carbon nitride-enhanced vanadium ferrite (VFe2O4@g-C3N4) as a photocatalyst for degrading SUF, CIP and ERY in an aqueous solution. VFe2O4@g-C3N4 was characterized with X-ray diffractometry (XRD), thermogravimetry analysis (TGA), ultraviolet (UV)-visible spectrophotometry, scanning electron microscope (SEM) and transmission electron microscope (TEM). The XRD characterization of VFe2O4@g-C3N4 revealed diffraction patterns with a crystallite size of 22.45 nm and a bandgap energy of 1.94 eV. The SEM image revealed the surface to be rough with irregular particle shape and size. The TEM image showed an average particle size of 92.47 nm. VFe2O4@g-C3N4 exhibited a degradation efficiency, which showed complete removal of SUF (100 %) from solution while the efficiency towards CIP is 94 ± 0.60 % and 90 ± 0.8 % towards ERY. The best photocatalytic performance was achieved with 0.12 g L−1 of VFe2O4@g-C3N4 and pH = 7.0 as the optimal conditions for achieving complete removal of SUF, CIP and ERY at a concentration lower than 10.00 mg L−1 under visible-light irradiation. The photodegradation of SUF, CIP and ERY by VFe2O4@g-C3N4 was found to be promoted by ROS with ˙OH and SO4˙− radicals playing a significant role. VFe2O4@g-C3N4 demonstrated a regeneration capacity that is above 90 % at the 10th cycle of regeneration treatment, suggesting it to be stable and reusable with the X-ray diffraction pattern remaining unchanged and no leaching of VFe2O4@g-C3N4 into solution. The result from the study reveals VFe2O4@g-C3N4 as a promising photocatalyst for removing antibiotics from an aqueous solution.

Stability of Cs2NaBiBr6 and Cs2NaBiCl6.

Bismuth-based halide perovskites are nontoxic alternatives to widely studied lead-based perovskites for optoelectronic applications. Here, we synthesized Cs2NaBiCl6 thin films and attempted to synthesize Cs2NaBiBr6 using physical vapor deposition. While Cs2NaBiCl6 forms a stable cubic structure with a 3.4 eV band gap and could be synthesized successfully, Cs2NaBiBr6 does not form and is unstable with respect to dissociation into Cs3-xNaxBi2Br9 and Cs3-xNaxBiBr6. Furthermore, the close X-ray diffraction patterns of Cs3-xNaxBi2Br9 and Cs2NaBiBr6 raise doubts about the previous reports of the latter's formation based on X-ray diffraction alone.

Crystallographic phase identifier of a convolutional self-attention neural network (CPICANN) on powder diffraction patterns.

Spectroscopic data, particularly diffraction data, are essential for materials characterization due to their comprehensive crystallographic information. The current crystallographic phase identification, however, is very time consuming. To address this challenge, we have developed a real-time crystallographic phase identifier based on a convolutional self-attention neural network (CPICANN). Trained on 692 190 simulated powder X-ray diffraction (XRD) patterns from 23 073 distinct inorganic crystallographic information files, CPICANN demonstrates superior phase-identification power. Single-phase identification on simulated XRD patterns yields 98.5 and 87.5% accuracies with and without elemental information, respectively, outperforming JADE software (68.2 and 38.7%, respectively). Bi-phase identification on simulated XRD patterns achieves 84.2 and 51.5% accuracies, respectively. In experimental settings, CPICANN achieves an 80% identification accuracy, surpassing JADE software (61%). Integration of CPICANN into XRD refinement software will significantly advance the cutting-edge technology in XRD materials characterization.

Electric field emission in GdNiO3 microflower

GdNiO3 microflowers were synthesized by hydrothermal method with unit sizes of about 2.2–3.5 μm and petal sizes of ∼75–100 nm. The X-ray diffraction pattern (XRD) and Raman spectra reveal an orthorhombic crystal structure with the space group Pbnm and various Raman active vibrational modes i.e., Ag, B1 g, B2 g associated with rare earth nickelates. The total density of states (TDOS) was calculated by density functional theory (DFT) study using a hybrid functional (HSE06) and the volume of TDOS near the Fermi level confirms the semiconducting nature of GdNiO3 with band gap ∼0.688 eV. The local bulk work function (φ) was estimated theoretically at ∼5.35 eV from DFT calculations which is one of the essential parameters for the field enhancement factor (β). Field emission current density (J) vs. applied electric field (E) divulges a low turn-on field (Eto)∼4.6 V/μm@1 μA/cm2 and a threshold field (Eth)∼5.2 V/μm@10 μA/cm2 respectively. The Fowler-Nordheim (F-N) model was introduced to calculate β ∼1637 and long-term field emission current stability was observed experimentally > 4 h at the preset values of current 2 μA and 10 μA, respectively. The easy preparedness, low turn-on field, and long-term current stability without significant decay suggest this material to be an efficient electron field emitting material in the rare-earth nickelates series.

Euglena gracilis Protein: Effects of Different Acidic and Alkaline Environments on Structural Characteristics and Functional Properties.

Due to the growing demand for human-edible protein sources, microalgae are recognized as an economically viable alternative source of proteins. The investigation into the structural characteristics and functional properties of microalgin is highly significant for its potential application in the food industry as an alternative source of protein. In this research, we extracted protein from Euglena gracilis by using alkaline extraction and acid precipitation and investigated its structural characteristics and functional properties in different acidic and alkaline environments. The molecular weight distribution of Euglena gracilis protein (EGP), as revealed by the size exclusion chromatography results, ranges from 152 to 5.7 kDa. EGP was found to be rich in hydrophobic amino acids and essential amino acids. Fourier infrared analysis revealed that EGP exhibited higher α-helix structure content and lower β-sheet structure content in alkaline environments compared with acidic ones. EGP exhibited higher foaming properties, emulsifying activity index, solubility, free sulfhydryl, and total sulfhydryl in pH environments far from its isoelectric point, and lower fluorescence intensity (2325 A.U.), lower surface hydrophobicity, larger average particle size (25.13 µm), higher emulsifying stability index, and water-holding capacity in pH environments near its isoelectric point. In addition, X-ray diffraction (XRD) patterns indicated that different acidic and alkaline environments lead to reductions in the crystal size and crystallinity of EGP. EGP exhibited high denaturation temperature (Td; 99.32 °C) and high enthalpy (ΔH; 146.33 J/g) at pH 11.0, as shown by the differential scanning calorimetry (DSC) results. The findings from our studies on EGP in different acidic and alkaline environments provide a data basis for its potential commercial utilization as a food ingredient in products such as emulsions, gels, and foams.

Smectite Illitization Geothermometry of the Upper Indus Basin Hydrocarbon Source Rocks (Pakistan)

Abstract —Smectite illitization geothermometry has been used to assess the thermal maturity and hydrocarbon generation potential of the late Paleocene to early Eocene Patala Formation in the Upper Indus Basin. X-ray diffraction (XRD) detected illite, muscovite, quartz, kaolinite, chlorite, and calcite. Comparison between air-dried (AD) and ethylene glycol (EG)-solvated XRD patterns reveals the absence of discrete smectite and interstratified illite-smectite (I-Sm). Additionally, authigenic illite-2M1 indicates that the Patala Formation has entered the late-stage diagenetic zone or the low anchizone, which lies in the R3 illitization zone. Abundant SiO2 and Al2O3 in the Patala clay fraction indicate the substitution of tetrahedral Si4+ by Al3+ within the smectite interlayers. Likewise, the relative abundance of K2O to CaO and MgO indicates the exchange of K+ with Ca2+ and Mg2+ during smectite illitization. Scanning electron microscopy (SEM) reveals in situ growth of platy illite crystals that form within the R3 zone. Furthermore, the total organic carbon (TOC) of the Patala shale exposed in Tirah suggests a poor to good source rock. The absence of discrete smectite and I-Sm, combined with the detection of discrete illite in the Patala shale, suggests that hydrocarbon might have potentially migrated from the source to the reservoir rock during smectite illitization.

Preparation and Characterization of Lutein Co-Amorphous Formulation with Enhanced Solubility and Dissolution.

Lutein is an oxygenated fat-soluble carotenoid and a functional compound with proven health benefits for the human body. Nevertheless, the poor water solubility and low oral bioavailability of lutein greatly limit its application. To address this, we developed an effective approach to enhance the water solubility of lutein through co-amorphous formulation. Specifically, the lutein-sucralose co-amorphous mixture was prepared at a molar ratio of 1:1 using ethanol and water as solvents by employing the solvent evaporation method, followed by solid-state characterization and dissolution testing conducted to assess the properties of the formulation. The X-ray diffraction pattern with an amorphous halo and the differential scanning calorimetry thermogram with no sharp melting peaks confirmed the formation of a binary co-amorphous system. Changes in peak shape, position, and intensity observed in the Fourier transform infrared spectroscopy spectrum revealed intermolecular interactions between lutein and sucralose molecules, while molecular dynamics simulations identified interaction sites between their hydroxyl groups. Additionally, dissolution testing demonstrated better dissolution performance of lutein in the co-amorphous form compared to pure lutein and physical mixture counterparts. Our findings present a novel strategy for improving the water solubility of lutein to make better use of it.

Influence of Selenium Oxide on Structure and Properties of New Zinc Boroselenite Glasses

AbstractThe traditional melt quenching method was used to prepare new zinc boroselenite glasses in the system xSeO2·(50 − x)ZnO·50B2O3 with varying SeO2/ZnO molar ratio. X-ray diffraction patterns (XRD) have revealed an amorphous structure in glasses of up to 40 mol pct SeO2. On the other hand, the presence of sharp diffraction peaks on the XRD spectra of samples containing 40 and 50 mol pct SeO2 confirms a formation of some polycrystalline phases distributed in the host glass network. Based on FTIR and NMR data, the glass structure at a short-range order exhibited a similar value of the fraction of tetrahedral boron (N4), particularly, for both samples of 0 and 5 mol pct SeO2. In this situation, SeO2 is as well as ZnO both played a modifier role. On the other hand, increasing SeO2 on expense of ZnO decreases the N4 fraction gradually. However, in SeO2-rich glass, most of boron atoms are mainly placed in three coordinated sites in BO3 units coordinated with SeO4 groups. Decreasing N4 fraction and increasing crystallization confirmed that SeO2 operates as a glass former and mainly as a crystalline agent. The results based on the TEM of the selected area of electron diffraction patterns (EDP) agree well with the ones obtained by XRD. The diffraction patterns clearly displayed two sets of diffraction rings: one is caused by boroselenite nanocrystals and the other by zinc selenite. In contrast, a broader halo of dispersed structure, known as an amorphous structure, is present in the diffraction pattern obtained from SeO2-free glass.

Comparative Study of Physicochemical Properties and Antibacterial Potential of Cyanobacteria Spirulina platensis-Derived and Chemically Synthesized Silver Nanoparticles.

The "green synthesis" of nanoparticles (NPs) offers cost-effective and environmentally friendly advantages over chemical synthesis by utilizing biological sources such as bacteria, algae, fungi, or plants. In this context, cyanobacteria and their components are valuable sources to produce various NPs. The present study describes the comparative analysis of physicochemical and antibacterial properties of chemically synthesized (Chem-AgNPs) and cyanobacteria Spirulina platensis-derived silver NPs (Splat-AgNPs). The physicochemical characterization applying complementary dynamic light scattering and transmission electron microscopy revealed that Splat-AgNPs have an average hydrodynamic radius of ∼ 28.70 nm and spherical morphology, whereas Chem-AgNPs are irregular-shaped with an average radius size of ∼ 53.88 nm. The X-ray diffraction pattern of Splat-AgNPs confirms the formation of face-centered cubic crystalline AgNPs by "green synthesis". Energy-dispersive spectroscopy analysis demonstrated the purity of the Splat-AgNPs. Fourier transform infrared spectroscopy analysis of Splat-AgNPs demonstrated the involvement of some functional groups in the formation of NPs. Additionally, Splat-AgNPs demonstrated high colloidal stability with a zeta-potential value of (-50.0 ± 8.30) mV and a pronounced bactericidal activity against selected Gram-positive (Enterococcus hirae and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Salmonella typhimurium) bacteria compared with Chem-AgNPs. Furthermore, our studies toward understanding the action mechanism of NPs showed that Splat-AgNPs alter the permeability of bacterial membranes and the energy-dependent H+-fluxes via FoF1-ATPase, thus playing a crucial role in bacterial energetics. The insights gained from this study show that Spirulina-derived synthesis is a low-cost, simple approach to producing stable AgNPs for their energy-metabolism-targeted antibacterial applications in biotechnology and biomedicine.

Stabilizing atomic Ru species in conjugated sp2 carbon-linked covalent organic framework for acidic water oxidation

Suppressing the kinetically favorable lattice oxygen oxidation mechanism pathway and triggering the adsorbate evolution mechanism pathway at the expense of activity are the state-of-the-art strategies for Ru-based electrocatalysts toward acidic water oxidation. Herein, atomically dispersed Ru species are anchored into an acidic stable vinyl-linked 2D covalent organic framework with unique crossed π-conjugation, termed as COF-205-Ru. The crossed π-conjugated structure of COF-205-Ru not only suppresses the dissolution of Ru through strong Ru-N motifs, but also reduces the oxidation state of Ru by multiple π-conjugations, thereby activating the oxygen coordinated to Ru and stabilizing the oxygen vacancies during oxygen evolution process. Experimental results including X-ray absorption spectroscopy, in situ Raman spectroscopy, in situ powder X-ray diffraction patterns, and theoretical calculations unveil the activated oxygen with elevated energy level of O 2p band, decreased oxygen vacancy formation energy, promoted electrochemical stability, and significantly reduced energy barrier of potential determining step for acidic water oxidation. Consequently, the obtained COF-205-Ru displays a high mass activity with 2659.3 A g−1, which is 32-fold higher than the commercial RuO2, and retains long-term durability of over 280 h. This work provides a strategy to simultaneously promote the stability and activity of Ru-based catalysts for acidic water oxidation.

Controlling the Orientation-Dependent Second Harmonic Generation in Hybrid Germanium Perovskites.

Manipulating the crystal orientation plays a crucial role in the conversion efficiency during second harmonic generation (SHG). Here, we provide a new strategy in controlling the surface-dependent anisotropic SHG with the precise design of (101) and (2 0) MAGeI3 facets. Based on the SHG measurement, the (101) MAGeI3 single crystal exhibits larger SHG (1.3×(2 0) MAGeI3). Kelvin probe force microscopy imaging shows a smaller work function for the (101) MAGeI3 compared with the (2 0), which indirectly demonstrates the stronger intrinsic polarization on the (101) surface. X-ray photoelectron spectroscopy confirms the band bending within the (101) facet. Temperature-dependent steady-state and time-resolved photoluminescence spectroscopy show shorter lifetime and wider emission band in the (101) MAGeI3 single crystal, revealing the higher defect states. Additionally, powder X-ray diffraction patterns show the (101) MAGeI3 possesses larger in-plane polar units [GeI3]- density, which could directly enhance the spontaneous polarization in the (101) facet. Density functional theory (DFT) calculation further demonstrates the higher intrinsic polarization in the (101) facet compared with the (2 0) facet, and the larger built-in electric field in the (101) facet facilitates surface vacancy defect accumulation. Our work provides a new angle in tuning and optimizing hybrid perovskite-based nonlinear optical materials.

Impact of zinc concentration and annealing temperature on the structural, optical, and photoelectrochemical properties of nickel oxide thin films synthesized by electrodeposition method

In this study, Zinc (Zn)- doped nickel oxide (NiO) thin films were fabricated via the electrodeposition method. The synthesized films were created with different concentrations of Zn (2 %, 4 %, 6 %, and 8 %) after that annealed at two different temperatures (300 °C and 500 °C). The prepared samples were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (RAM), UV–vis spectrophotometry, photocurrent (PC), photoluminescence (PL), electrochemical impedance spectroscopy (EIS), Energy-Dispersive X-ray spectroscopy (EDX), photocurrent (PC), and Mott-Schottky (MS) analysis. XRD patterns indicate that Zn: NiO thin films have a cubic phase, with the (111) direction as the preferred orientation. Various structural parameters such as dislocation density, stacking fault, lattice strain, and crystallite size have been determined. The presence of Zn doping in NiO has been confirmed by EDX analysis. The EDX mapping of elements revealed the uniform distribution of Ni, Zn, and O in the sample. The optical transmittance and absorbance were analyzed using a UV–vis spectrophotometer. The lowest transmittance values were found for 8 % Zn: NiO thin films annealed at 300 °C and 500 °C. The absorption edge corresponding to pure NiO-300 °C and NiO-500 °C has been observed at 300 and 320 nm, respectively. The band gap energy (Eg) decreased to 3.88 eV for 8 %Zn: NiO (300 °C) and 3.71 eV for 8 %Zn: NiO (500 °C). The Raman analysis showed three distinct peaks at 590 cm−1, 705 cm−1, and 1172 cm−1, which correspond to the vibration of Ni—O bonds. The SEM results indicated that increasing the doping concentration and annealing temperature resulted in larger grain sizes in the manufactured samples. Furthermore, the PL spectra analysis of the synthesized films revealed two distinct emission peaks at around 400 and 490 nm. PC analysis confirmed the p-type conductivity of manufactured arrays. From MS measurements, the highest carrier concentration (NA) values of 8.81×1018 cm−3 and 9.41×1019 cm−3 were obtained for 8 %Zn: NiO (300 °C) and 8 %Zn: NiO (500 °C), respectively. EIS analysis confirmed the highest conductivity and enhanced electrochemical activity for 6 % Zn: NiO (500 °C) and 8 % Zn: NiO (300 °C). These results suggest that Zn-doped NiO is suitable for optoelectronic applications.

Synthesis, characterization,photocatalyticand bactericidal propertiesof Ag3PO4/NiCo-metal–organic framework composite irradiated by white light emitting diode

In this paper, Ag3PO4/NiCo-MOF composites were synthesized with different mass contents of NiCo-MOF (5, 10, and 20wt%) from silver phosphate crystals (Ag3PO4) and sheets of metal–organic frameworks of nickel and cobalt (NiCo-MOF). The materials were characterized, and their photocatalytic and bactericidal properties were evaluated against the bacteria Staphylococcus aureus (S. aureus) and Escherichia coli (E coli) incubated under exposure to white light emitting diode (WLED). X-ray diffraction (XRD) patterns of Ag3PO4 and NiCo-MOF confirm the formation of crystals without a deleterious phase. Field emission scanning electron microscopy (FE-SEM) images showed polymorphism with shape predominant to tetrahedron-like Ag3PO4 microcrystals and sheets for NiCo-MOF. The materials showed band gap energy values between 2.32 eV and 3.60 eV. Fourier-transform infrared (FTIR) spectroscopy shows the formation of molecular interaction between the materials. Bacterial susceptibility tests showed a reduction in Minimum Bactericidal concentration (MBC) values to 64 μg/mL when incubated with Ag3PO4 under WLED exposure. The Ag3PO4/NiCoMOF-5wt% composite, incubated without light, showed MBC values of 64 μg/mL for S. aureus and 32 μg/mL for E. coli, respectively. Based on the results, the composite in the absence of WLED showed superior bactericidal results.

Enhancement in Sensitivity and Selectivity of Electrochemical Technique with CuO/g-C3N4 Nanocomposite Combined with Molecularly Imprinted Polymer for Melamine Detection.

This study focused on enhancing the sensitivity and selectivity to detect melamine by utilizing a photoelectrochemical method. This was achieved by combining a melamine-imprinted polymer with a CuO/g-C3N4 nanocomposite, which was synthesized through chemical precipitation and calcination. The resulting nanocomposite exhibits improved carrier mobility and photoelectrochemical properties. A molecularly imprinted receptor for selective detection was created through bulk polymerization with methacrylic acid and a melamine template. The characterization of the nanocomposite was performed using X-ray photoelectron spectroscopy for the chemical oxidation state, X-ray diffraction patterns for the crystalline structure, and ultraviolet/visible/near-infrared spectroscopy for optical properties. The CuO/g-C3N4 nanocomposite exhibits photoactivity under visible light. The modified electrode, incorporating the CuO/g-C3N4 nanocomposite and melamine-imprinted polymer, demonstrates a linear detection range of 2.5 to 50 nM, a sensitivity of 4.172 nA/nM for melamine, and a low detection limit of 0.42 nM. It shows good reproducibility and high selectivity to melamine, proving effective against interferences and real samples, showcasing the benefits of the molecularly imprinted polymer.