Absorption Bands Research Articles

Conformal zinc sulfide coating of vertically aligned ZnO nanorods by two-step hydrothermal synthesis on wide bandgap seed layers for lead-free perovskite solar cells

Vertically aligned ZnO nanorods (NRs) were grown hydrothermally on the wide bandgap (∼3.86 – 4.04 eV) seed layers (SLs) of grain size ∼162 ± 35 nm, prepared using ball-milled derived ZnO powder. The synthesized ZnO NRs were further decorated with ZnS nanocrystals to achieve a ZnO NR-ZnS core–shell (CS)-like nano-scaffolds by a subsequent hydrothermal synthesis at 70 °C for 1 h. UV-Vis-NIR spectroscopy, x-ray diffractometry (XRD), Raman spectroscopy and Field emission scanning electron microscopy (FESEM) coupled with Energy dispersive x-ray spectroscopy (EDX) analyses confirmed the formation of ZnS atop the vertically aligned ZnO NR arrays of ∼1.79 ± 0.17 µm length and ∼165 ± 27 nm diameter. Transmission electron microscopy (TEM)/EDX analyses revealed that vertically aligned ZnO NRs (core dia. ∼181 ± 12 nm) arrays are conformally coated by an ultrathin ZnS (∼25 ± 7 nm) shell layer with a preferential ZnS{111}/ZnO{10-10}-like partial epitaxy. The ZnO NRs exhibited a sharp band edge near ∼384 nm having optical bandgap energy (E g) of ∼3.23 eV. However, the ZnO NR-ZnS CS exhibited double absorption bands at E g ∼ 3.20 eV (ZnO-core) and E g ∼ 3.78 eV (ZnS-shell). The ZnS{111}/ZnO{10-10}-nano-scaffolds could be utilized to facilitate the enhanced absorption of UV photons as well as the radial junction formation between the Pb-free perovskite absorber and ZnS/ZnO NRs layers.

Investigating extrusion impact on functional, textural properties, morphological structure, and molecular interactions in hulless barley-based extruded snacks supplemented with mung bean.

The effect of varying extrusion conditions on the functional properties of hulless barley-mung bean (70:30) extruded snacks was investigated using response surface methodology with feed moisture (FM), barrel temperature (BT), and screw speed (SS) as process variables. Results revealed significant impacts on functional characteristics with varying extrusion conditions. Bulk density (BD) of extruded snacks ranged from 0.24 to 0.42 g/cm3, showing that lower FM and higher BT results in lower BD while it increased with increasing FM, SS, and BT. The expansion ratio (ER) of extruded snacks ranged between 2.03 and 2.33, showing BT and SS had a desirable positive effect, whereas increasing FM led to decreased ER. Increasing BT and SS depicted a negative effect on water absorption index, whereas FM showed positive effect, which ranged between 4.21 and 4.82 g/g. A positive effect on water solubility index was depicted by BT and SS, which ranges between 9.01% and 13.45%, as higher SS and BT led to starch degradation and increased solubility suggesting better digestibility. The hardness of extruded snacks ranged from 32.56 to 66.88 Newton (N), showing increasing FM increased hardness, whereas higher SS and BT resulted in lowering the hardness. Scanning electronic microscope (SEM) analysis revealed structural changes in extrudates in comparison with nonextruded flour, indicating starch gelatinization and pore formation affected by varying processing parameters. Shifts in absorption bands were observed in Fourier transform infrared spectroscopy (FT-IR), suggesting structural changes in starch and protein. Understanding the effects of extrusion parameters on product properties can help tailored production to meet consumers' preferences and the development of functional snacks with improved nutritional quality.

Study of Microstructure, Morphology and Functional Groups of Titanium Dioxide (Tio2) Impregnated With Copper (Cu)

This research aims to determine the differences in the microstructure, morphology, and functional groups of TiO2 (P-25) after being impregnated with Cu. Cu-impregnated TiO2 samples are synthesized using the impregnation method with TiO2 (P-25) and copper sulfate as precursors. The microstructure and functional groups of TiO2 (P-25) and Cu-TiO2 were investigated using X-ray diffraction (XRD), scanning electron microscope-energy dispersive x-ray (SEM-EDX), and Fourier transform infrared (FTIR) analysis. The lattice parameters (a, b, and c) of the TiO2 sample were found to be a = b = 0.3778 nm, c = 0.9494 nm, and these values increased to a = b = 0.3779 nm, c = 0.9496 nm after the addition of Cu. The distance between the lattices of the TiO2 sample was measured at 0.3505 nm and increased to 0.3509 nm after Cu addition. The average crystallite size of the TiO2 sample was 33 nm, which increased to 43 nm after Cu impregnation. The strain value decreased from 2.76×10^(-3) to 1.82×10^(-3) after Cu addition. SEM results revealed that the morphology of the particles from the Cu-doped synthesis showed agglomeration. The success of Cu doping was confirmed by EDX mapping, which showed the presence of Ti, O, and Cu evenly distributed on the TiO2 surface. The FTIR spectrum indicated that TiO2 (P-25) and Cu-TiO2 particles had absorption peaks at similar wave numbers. However, in the absorption area of 1000 cm^-1 to 1250 cm^-1, new absorption bands affiliated with Cu-O bonds appeared in the Cu-TiO2 sample, resulting from TiO2 vibrations after Cu addition.

Characterization of Copper nanoparticles obtained in AOT reverse micelles using flavonoids as a reducing agent

Purpose of the study. To characterize copper nanoparticles obtained in reverse micelles of sodium bis-(2-ethylhexyl)-sulfosuccinate (AOT) using flavonoids: quercetin and rutin in comparison with traditional reducing agents - sodium borohydride and hydrazine. Methods. Chemical synthesis of copper nanoparticles, spectrophotometry to determine the maximum of the plasmon absorption band of copper nanoparticles, electron transmission microscopy. Results. The reduction of copper ions using flavonoids – quercetin and rutin – confirmed the possibility of obtaining copper nanoparticles in the Cu+2/AOT/isooctane system (AOT is sodium bis-(2-ethylhexyl)-sulfosuccinate, an anionic surfactant that forms the micelle shell). During the formation of nanoparticles, “plasmonic” absorption bands were observed in the electronic spectra in the region of 400-440 nm. In the case of the traditional reducing agent, sodium borohydride, absorption is observed in the region of (439 ± 3) nm, which can also be attributed to the “plasmonic band” of copper nanoparticles, but its intensity is very low, which indicates the formation of a small amount of copper nanoparticles. Using transmission electron microscopy. The average size of copper nanoparticles was determined: 7.1, 8.2 and 18.5 nm in the case of quercetin, rutin and hydrazine, respectively. From the histograms constructed from the results of electron transmission microscopy, it follows that the use of flavonoids as reducing agents makes it possible to reduce the average size of copper nanoparticles and narrow their size distribution. Conclusion. Copper nanoparticles obtained in a reverse micellar solution of AOT in iso-octane using the flavonoids quercetin and rutin as a reducing agent have an average size of 7-8 nm and a narrower size distribution compared to reduction with hydrazine.

Integrated Intensities of the Main Absorption Band of С2HD in the 6530–6627 cm–1 Region

Integrated Intensities of the Main Absorption Band of С2HD in the 6530–6627 cm–1 Region

Aza-BODIPY-based logic gate chemosensors and their applications

Dimethylaniline-substituted aza-BODIPY dyes (DA, DM, DP) were designed and synthesized aiming for ion detection. The Zn2+ recognition ability was found in all compounds and the binding mechanism was possibly via dimethylaniline sites linked to the aza-BODIPY core. Upon Zn2+ addition, the new absorption band and the color change occurred due to the altered charge transfer of the adducts. The custom-made colorimeter was successfully integrated into the dye’s application, demonstrating a good linear relationship between resistance values and Zn2+ concentration. The chromophore test strips were fabricated and exhibited distinct color changes upon aqueous Zn2+ exposure. The compound DA also exhibits logical behavior with DA-Zn2+-Cu2+ system. In terms of environmental hazards, the compounds exhibited no adverse effect on Pseudomonas putida at the concentration level of 0.2 mg/mL. These findings indicated that all synthesized aza-BODIPYs might be suitable for chemosensor probes for Zn2+ detection with possibly low environmental risk.

Evidence of microplastic contamination in the food chain: an assessment of their presence in the gastrointestinal tract of native fish

This research study focused on the primary freshwater surface sources of Khyber Pakhtunkhwa (KP) province, Pakistan—Swat and Kabul rivers. The study aimed to assess microplastic (MP) contamination of fish in the Swat and Kabul rivers. Understanding this contamination is vital for evaluating the environmental and health risks associated with consuming contaminated fish and contributing to the ongoing conservation efforts. The study’s objective was to investigate the presence of MPs in the gastrointestinal tracts (GIT) of fish and to delineate the identified MP types. Samples of local dominant fish (Schizothorax plagiostomus [Swatay] and Racoma labiata [Chunr], Cyprinus carpio [Common Carp], and Clupisoma naziri [Sher Mayai]) were collected, and their body weight and length assessed to gauge the overall health. The GIT samples were processed, digested and filtered before microscopic examination to detect MPs. Subsequently, the identified MPs were subjected to attenuated total reflectance–Fourier transform infrared spectroscopy for characterization by analyzing their absorption bands. Results of the study showed the presence of MPs in fish samples, predominantly identified as polyethylene (PE), with polypropylene (PP) being the subsequently prevalent plastic type, which manifested fish contamination with MPs. The study revealed MP pollution in both Swat and Kabul rivers, with fish ingesting these particles. This poses potential health risks for fish and health of the ecosystem.

Design and Photophysical Characterization of Dinuclear Lanthanide Complexes Incorporating Spacer Ligands along with their Mononuclear Analogues: A Comparative Study

Two heteroleptic homo-dinuclear complexes of Dy(III) and Sm(III) with pyrazine (pyz) as spacer ligand [Ln(TFPB)3(μ-pyz)Ln(TFPB)3], along with their mononuclear analogue [Ln(TFPB)3(pyz)2] were synthesized and characterized. Diketone TFPB (4,4,4-trifluoro-1-phenyl-1,3-butanedione) was incorporated as main ligand. NMR analysis depicted single peak for pyz protons for dinuclear complexes and two for mononuclear ones, which confirmed the bridging nature of pyz in former complexes. UV spectra revealed two absorption bands despite of the different metal ion and nuclearity of complex, suggesting the absorption of UV-radiation by coordinated moieties inspite of the metal ion involved. The emission spectra exhibited significant intensity of yellow and orange-red peaks for Dy(III) and Sm(III) complexes, respectively, indicating effective sensitization of metal center. The enhanced emission intensity observed in dinuclear Sm-complexes, compared to their mononuclear counterparts, indicates a synergistic effect of the two metal ions on the overall emission properties, rather than a mere additive effect that would be expected from two independent mononuclear units. The photoluminescent properties of synthesized complexes were examined and discussed, suggesting potential applications in display devices. The Correlated Color Temperature (CCT) of these complexes falls within a range suitable for warm light sources and the highest branching ratio observed for 4G5/2 → 6H9/2 (for Sm3+ ion) and 4F9/2 → 6H13/2 (for Dy3+ ion) transitions suggests potential application in laser amplification. The alignment between band gap measurements obtained from UV and CV analyses highlight the possibility of employing these complexes in semiconductor technologies.

The effect of heat treatment on zircon color and its enhancement mechanism

The effect of heat treatment on zircon color was studied from a new perspective of chromaticity of gemstones. The mechanism behind zircon color enhancement was investigated through the combination of infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and UV–vis spectroscopy. The study reveals that the color of zircon has no significant correlation to the degree of metamorphism, which decreases as heating temperature rises. Type I and Type II defects in zircon are characterized by the deletion of an oxygen atom at the nearest site to Y3+ occupied by the Zr4+ and the loss of electrons at the next nearest oxygen atom to Y3+, respectively. These defects lead to broad absorption bands in the UV–vis spectra ranging from 340 nm and 500 nm, respectively. Additionally, there is a correlation between the color of zircon and the strength of the relationship between the two absorption bands. After undergoing heat treatment, the first defects to be repaired were type II, followed by type I. Subsequently, the zircon appeared colorless after both types of defects had been corrected.

Synthesis, structure, spectral and luminescence studies of novel guanidinium aryl(oxy)(sulfanyl)(sulfonyl)acetates

A series of promising luminescent materials, nonlinear optical crystals, and physiologically active compounds – aryl(oxy)(sulfanyl)(sulfonyl)acetates of guanidine (A) of unknown type was synthesized. Various functional groups present in (A) were identified using FTIR spectroscopy. 1H and 13C NMR spectral studies further confirm the molecular structure (A). Crystals of guanidinium 4-chlorophenyl(sulfanyl)acetate (1) and guanidinium 4-chlorophenyl(sulfonyl)acetate (2) were successfully grown. They belong to the same lowest symmetry category, but to different crystal systems: monoclinic (1) and orthorhombic (2).It has been established that intrinsic optical absorption begins at a wavelength of ∼ 290 nm for crystalline compound (1) and ∼ 335 nm for crystal (2). The intrinsic luminescence spectrum of crystal (1) includes two bands with maxima at 300 and 515 nm. In the intrinsic luminescence spectrum of crystal (2), only one band is observed with a maximum at 350 nm. Such luminescence in both crystals is excited in the intrinsic absorption bands, as well as by X-ray radiation. In addition, in the near ultraviolet and throughout the visible region, where optical absorption is not detected (it is very weak), low-inertia (less than 10 ns) rather intense luminescence of uncontrolled impurity-defect centers is excited.The spectral bands of optical absorption, photo- and X-ray luminescence discovered in experiments were systematized using a diagram of energy levels and quantum transitions in crystals and defect centers of the compounds under study.

Near-infrared spectroscopy identification method of cashmere and wool fibers based on an optimized wavelength selection algorithm

Cashmere and wool fibers have similar chemical compositions, making them difficult to distinguish based on their absorption peaks and band positions in near-infrared spectroscopy. Existing studies commonly use wavelength selection or feature extraction algorithms to obtain significant spectral features, but traditional algorithms often overlook the correlations between wavelengths, resulting in weak adaptability and local optimum issues. To address this problem, this paper proposes a recognition algorithm based on optimal wavelength selection, which can remove redundant information and make the model effective in capturing patterns and key features of the data. The wavelengths are rearranged by computing the information gain ratio for each wavelength. Then, the sorted wavelengths are grouped based on equal density, which ensures that all wavelengths within each group have equal information and avoids over-focusing on individual groups. Meanwhile, the group genetic algorithm is used to find the wavelengths with highly informative and search optimal grouped combinations, in order to explore the entire spectrum wavelength. Finally, combined with a partial least squares discriminant analysis(PLS-DA) model, the recognition accuracy reached 97.3 %. The results indicate that, compared to traditional methods such as CARS, SPA, and GA, our method effectively reduces redundant information, selects fewer but more informative wavelengths, and improves classification accuracy and model adaptability.

Analysis of Devanur and Manamedu Ophiolite Complexes in SGT, India: A detailed examination employing remote sensing techniques and Laboratory Spectral Signature investigations

This study employs advanced satellite imagery from ASTER and Sentinel-2A to conduct detailed lithological mapping of the Devanur and Manamedu ophiolite complexes in the southern Central Shear Zone (CSZ). The primary focus is on the Manamedu Ophiolite Complex (MOC) and the Devanur Ophiolitic Complex (DOC). Image enhancement techniques such as Color composites, Principal Component Analysis (PCA), and Minimum Noise Fraction (MNF) were utilized to differentiate various rock types. RGB band combinations derived from PCA and MNF outputs demonstrated effective discrimination of rock units. Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) classification methods were employed on ASTER and Sentinel-2A images, yielding classified lithologies that closely matched existing maps from the Geological Survey of India (GSI) and other studies, validating the accuracy of the findings. Additionally, Laboratory Spectral Signature Studies were conducted on 10 rock samples using an ASD FieldSpec Pro® spectroradiometer, providing reflectance spectra from 350 nm to 2500 nm. These spectra, particularly the continuum-removed reflectance, revealed diagnostic absorption features that were corroborated by geochemical analyses. A detailed analysis investigated how elemental compositions and key minerals influenced absorption bands. Major oxide geochemical compositions of DOC and MOC samples were identified using XRF methods. The aim of this research is to characterize DOC and MOC through remote sensing and spectral signature analysis. Sentinel-2A data proved more effective in lithological discrimination compared to ASTER, with spectral signatures indicating the presence of iron (Fe) and magnesium (Mg) contents. Notably, SVM classification of Sentinel-2A MNF + DEM data achieved an overall accuracy of more than 90% when compared with field investigations. This study underscores the efficacy of processing VNIR and SWIR bands from ASTER and Sentinel-2A satellite imagery alongside DEM data and ground surveys for mapping mafic-ultramafic rocks in the DOC and MOC regions of the CSZ.

Enhancing photocatalytic dye degradation efficiency through the utilization of shock wave effects on neodymium oxide (Nd2O3)

This article delves into the impact of shockwaves on neodymium oxide (Nd2O3) nanoparticles, aiming to evaluate their physical and chemical stability. Nd2O3 nanoparticles were subjected to varying sets of shock pulses (100, 200, and 300) in photocatalytic dye degradation. The nanoparticles crystallinity and unit cell volume after shockwave exposure were examined using powder X-ray diffraction (PXRD) analysis with unit-cell software. PXRD data revealed no alterations in the crystalline structure, lattice parameter and unit cell volume. Comparisons between pre- and post-shockwave field emission scanning electron microscopy (FE-SEM) portraying data demonstrate that repeated shockwave application causes a decrease in particle size. Raman spectroscopy, under ambient conditions, shows a high intensity after shock conditions intensity will decrease. Furthermore, FTIR spectroscopy revealed the characteristic strong and broad absorption band associated with metal-oxygen (Nd-O) groups in the Nd2O3 nanoparticles. UV–Vis diffuse reflectance spectroscopy (DRS) was used to investigate the bandgap of the Nd2O3 nanoparticles. Initially, the bandgap was measured at 5.96 eV under ambient conditions, but following the shockwave exposure, it was decreased to approximately 5.91 eV. Interestingly, the surface area of the shockwave-treated Nd2O3 nanoparticles is increased and exhibited an increased efficiency in photocatalytic dye degradation. This finding holds promising implications for environmental remediation applications.

Impact of Gd-substitution on structural, dielectric, spectroscopic, Raman, and photo luminance properties of Ba0.4Sr0.6Co2Fe16O27 ceramics

This paper represents a detailed study of Gd3+ substitutions on Structural, Dielectric, Spectroscopic, Raman, and Photo luminance Properties of Ba0.4Sr0.6Co2Fe16O27 magnetic oxides were prepared using the sol-gel auto combustion method. All of these specimens were sintered at 1100 °C for 5 h. X-ray diffraction analysis (XRD) confirmed the single-phase detection and structural analysis. The lattice parameters a and c show the insignificant behavior 5.893–5.933 Å, and 32.049–32.476 Å with the concentration of gadolinium ions. The crystallite size ranged from 25 to 30 nm, demonstrating a growing tendency as Gd-substitution was enhanced. The discrepancy in the ionic radii of iron (Fe3+) and substituent elements (Gd3+) is the cause of the variation in cell volume and lattice constants. FTIR spectroscopy confirmed the presence of absorption bands (590 and 3000 cm−1) for prepared BaSr-based W-type hexa-ferrites. The vibrational bands of metal oxide ions are responsible for the 590 and 685 cm−1 peaks. The Raman spectrum showed six discrete, brittle peaks: 320, 440, 620, 690, 1300, and 1600 of synthesized nanomaterials—the dielectric constant and dielectric loss increase by substituting the Gd3+ ion. The dielectric parameters and dielectric loss at higher frequencies suggest that the prepared material may be excellent for switching, sensing, and high-frequency applications.

Oxygen-vacancies-rich TinO2n-1 quantum dots embedded Ti3CNTx/CNTs foam by HCl induced self-assembly and spontaneous oxidation towards strong and multiband microwave absorption

Ti3CNTx/TinO2n-1 foam and Ti3CNTx/CNTs/TinO2n-1 foam were prepared by hydrochloric acid (HCl) induced self-assembly and freeze-drying, during which oxygen-vacancies-rich TinO2n-1 quantum dots in situ grown on Ti3CNTx nanoflakes as a result of their slight and spontaneous oxidation. The well-developed pore structure, abundant interfaces, unique dangling bonds, defects and terminated groups on highly conductive Ti3CNTxnanoflakes, as well as the oxygen vacancies in TinO2n-1 quantum dots render the foams with superior impedance matching, intensive multiple reflection and dielectric loss. By immersing the foams into molten paraffin (absorber content: 4.2wt%), excellent microwave absorption (MA) properties were achieved: an effective absorption band width (EAB) of 5.2 GHz (1.55 mm) and a reflection loss (RL) of -81.3 dB (1.85 mm) for Ti3CNTx/TinO2n-1foam, and an EAB of 6.4 GHz and a RL of -54.3 dB (1.85 mm) for Ti3CNTx/CNTs/TinO2n-1 foam (15wt% CNTs). Moderate addition of CNTs enhanced the conduction loss and polarization loss, leading to a larger EAB. When adjusting the thickness (1.2-5 mm), the EAB of Ti3CNTx/TinO2n-1 foam (14.7 GHz) and Ti3CNTx/CNTs/TinO2n-1 foam (15.3 GHz) both covered the C, X and Ku band. This work offers a simple and facile method for constructing Ti3CNTx-based foams as excellent MA materials.

A novel multifunctional Eu3+/Mn4+ co-doping double perovskite phosphor for applications in LEDs and optical thermometry

In recent years, phosphors have played important roles in solid-state lighting, plant growth lighting and optical temperature measurement. In this work, novel La3Mg2NbO9:Eu3+,Mn4+ phosphors were successfully prepared by the high temperature solid phase method and innovative multimode applications were investigated in optical thermometry, plant growth and White-LEDs. The crystal structure, surface morphology, photoluminescence, temperature sensing properties and luminescence mechanism of La3Mg2NbO9:Eu3+,Mn4+ phosphors were investigated in detail. Benefiting from the different responses of Eu3+ and Mn4+ ions to temperature, the La3Mg2NbO9:0.06Eu3+,0.0095Mn4+ sample shows excellent optical thermometry performance in the range of 303 ∼ 478 K. The maximum values of relative sensitivity (Sr) reach 2.7 % K-1 (@478 K) according to the fluorescence intensity ratio method and the maximum of Sr is 5.2 % K−1 (@428 K) based on the fluorescence lifetime method. Furthermore, the electrochromic spectrum of the red pc-LED prepared using La3Mg2NbO9:0.06Eu3+,0.005Mn4+ phosphor perfectly overlapped with the absorption bands of the photosensitive pigments for planting, and another white pc-LED prepared using La3Mg2NbO9:0.06Eu3+,0.0025Mn4+ phosphor emitted bright white light with a color rendering index of 89.8, color coordinate of (0.3468, 0.3557) and correlated color temperature of 4945 K. All the results demonstrate that the La3Mg2NbO9:Eu3+,Mn4+ phosphors are promising for the field of non-contact optical temperature thermometry, plant lighting lamps and pc-LED backlit displays.

Broadband sensitized near-infrared emission in Eu2+-Nd3+ co-doped BaAl2O4 as a potential spectral modulator for silicon solar cells.

The near-infrared (NIR) down-conversion process for broadband sensitization has been studied in Eu2+-Nd3+ co-doped BaAl2O4. This material has a broad absorption band of 200-480 nm and can convert photons in the visible region into NIR photons. The NIR emission at 1064 nm, attributed to the Nd3+:4F3/2 → 4I11/2 transition, matches the bandgap of Si, allowing Si solar cells to utilize the solar spectrum better. The energy transfer (ET) process between Eu2+ and Nd3+ was demonstrated using photoluminescence spectra and luminescence decay curves, and Eu2+ may transfer energy to Nd3+ through the cooperative energy transfer (CET) to achieve the down-conversion process. The energy transfer efficiency (ETE) and theoretical quantum efficiency (QE) were 68.61% and 156.34%, respectively, when 4mol% Nd3+ was introduced. The results indicate that BaAl2O4:Eu2+-Nd3+ can serve as a potential modulator of the solar spectrum and is expected to be applied to Si solar cells.

Impact of Carbon Dots on the Structural, Morphological, Magnetic, and Electrochemical Performance of Zn Ferrite for Energy Storage Applications

Magnetic core-shell Zn ferrite and carbon dots (C-dots) composite have been synthesized in this work using a simple coprecipitation and hydrothermal process, respectively. X-ray diffraction (XRD) patterns demonstrate an inverse spinel structure of Zn ferrites; the lattice parameter has decreased from 8.19Å to 8.10Å with C-dots. Scanning electron microscopy (SEM) images reveal rods-like structures for C-dots, and in the composite case, it is uniformly dispersed using low contrast consecutive C-dot layers to produce a core-shell structure. Zn ferrites are non-uniform in size, whereas C-dots and their composites are in uniform shape according to SEM images. The energy dispersive X-ray (EDX) study indicates that the substitution has been successful. For Zn ferrites, and composite, the Fourier transform infrared (FTIR) spectra shows that the absorption band of the tetrahedral site at 990 cm-1, and 870 cm-1, respectively. Different bonds in the infrared spectrum match specific function groups and bonding in various chemicals. The vibrating sample magnetometry (VSM) results indicates that the composite displays ferrimagnetic behavior. The specific capacity for composite has been found to be 2351 and 1790 F/g using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements, respectively. Higher electrochemical performance of the prepared composites may be helpful for energy storage systems.

Zinc-doped hexaferrite exhibits altered physical properties in the presence of both Dy and Zn ions

The nanosized M-type hexaferrites SrFe11.5Zn0.5O19, Sr0.95Dy0.05Fe12O19, and Sr0.95Dy0.05Fe11.5Zn0.5O19 were produced by auto combustion utilizing citric acid. The impacts of substituting Zn2+ as well as Dy3+ ions upon the structural, electrical, magnetic, and optical properties of SrFe11.5Zn0.5O19, Sr0.95Dy0.05Fe12O19 and Sr0.95Dy0.05Fe11.5Zn0.5O19 nanoferrites have been studied using XRD, FTIR, UV–Visible, FESEM, VSM, and LCR meter. The formation of a single-phase lattice was confirmed by the XRD analyses. For the investigated samples, the crystallite size rose from 36 nm for SrFe11.5Zn0.5O19 to 37 and 33 nm, for Sr0.95Dy0.05Fe12O19, and Sr0.95Dy0.05Fe11.5Zn0.5O19 respectively. In FTIR spectra, a couple of absorption bands have been seen. The prepared samples possess a strong tendency to clump together into large masses, according to FSEM. The samples’ band gap values vary from 1.8 to 2.4 eV. Additionally, the dielectric parameters based on a Maxwell–Wagner two-layer approach have also been described. The results reveal that the dielectric constant (ε’) as well as dielectric loss (ε’’) decrease with increasing applied field frequency, whereas the AC conductivity (σac) increases. The VSM results show that all the investigated materials are referred to as hard magnetic materials.

Biopreparation of titanium dioxide nanoparticles mediated by Calendula officinalis flower extract for catalytic reduction of 4-nitrophenol and treatment of allergic conjunctivitis

This study investigates the an eco-friendly synthesis for the production of titanium dioxide nanoparticles (TiO2 NPs) by employing the water-soluble flower extract of Calendula officinalis as a natural reducing and stabilizing agent. The green produced TiO2 NPs/C. officinalis were characterized using different advanced analytical techniques, including FT-IR, FE-SEM, EDS-elemental mapping, XRD, ICP-OES and TEM. It represents the TiO2 NPs were found to be spherical in shape and well distributed without agglomeration. It also revealed the particle sizes were in the range of 30–50 nm. EDX represented the Ti atomic species along with C and O are seen to be well-dispersed in a homogeneous manner. The broad absorption band appeared at 3200–3450 cm−1 assigned to OH bond stretching belong to the adsorbed water over the titanium dioxide nanoparticles. Further, newly synthesized TiO2 NPs/C. officinalis are used as a nanocatalyst for the reduction of 4-nitrophenol (4-NP). A UV–Vis spectrophotometer is employed to track the effectiveness of the reduction process. Recyclability in 8 further degradation cycles is used to assess the sustainability of this catalyst, and the results show a steady and notable degradation activity. After a week of daily treatment, the allergic conjunctivitis clinical scores in Dunkin-Hartley guinea pigs were evaluated. The guinea pigs were sensitized with intraperitoneal ovalbumin and then subjected to topical conjunctival challenge. Different doses of TiO2 NPs/C. officinalis (20 and 100 µg/kg), prednisolone (30 mg/kg), chlorpheniramine (10 mg/kg), or PBS (10 mL/kg) were administered. The levels of serum Immunoglobulins were measured by ELISA. It was observed that the levels of ovalbumin-specific IgE notably decreased. Notably, the treatment with TiO2 NPs/C. officinalis at both doses led to a notably lower clinical score for allergic conjunctivitis. Furthermore, the TiO2 NPs/C. officinalis-treated guinea pigs conjunctival tissue showed mild mononuclear infiltration compared with the intense conjunctival tissue inflammatory infiltration observed in the PBS-treated group. These data suggest that TiO2 NPs/C. officinalis may have clinical efficacy in alleviating allergic conjunctivitis.