Field Emission Scanning Electron Microscopy Analysis Research Articles

A comparative investigation on the surface and physicochemical properties of organobimetallic thiocyanate complexes of Cadmium, Zinc, Mercury and Manganese

Abstract The single crystals of bimetallic thiocyanate ligands, namely manganese cadmium thiocyanate (MCTC), zinc cadmium thiocyanate (ZCTC), manganese mercury thiocyanate dimethylsulphoxide (MMTD), and cadmium mercury thiocyanate dimethylsulphoxide (CMTD), are cultivated through the utilization of slow solvent evaporation and gradual cooling methodologies. Through the utilization of optical microscopic techniques such as field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and epifluorescence, a state-of-the-art methodology extensively employed in the realms of biochemical, medical, and chemical research, we delve into the examination of growth mechanisms and surface topographies. It is additionally employed in LED, fluorescent, and various other luminous sources. The FESEM analysis of MCTC elucidates the manifestation of an extended dendritic growth pattern, which arises from the oscillation of the Mn and Cd metal ligands when connected by thiocyanate (SCN) bridges. The presence of three notable mounds exhibiting cavities within the multi-component thin film coating (MCTC) has been duly ascertained through the utilization of atomic force microscopy (AFM) imagery. The analysis of the histogram unveiled that the average diameter exhibited an augmentation concomitant with the alteration in the breadth of the distribution throughout the process of growth.

Surface topography and surface morphology of graphene nanocomposite by FESEM, EDX and AFM analysis

The analyzed nanocomposites of this research have been fabricated by the sintering method, where different percentages of boron nitride, zinc oxide, aluminum oxide and titanium oxide have reinforced graphene. The percentages of additives were varied from 0 % to 5 %. An investigation of nanostructural observation, phase identification and structural analysis of graphene nanoparticles has been performed using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) analysis and X-Ray Diffraction (XRD) analysis. The morphology of the synthesized materials was investigated by examining the FESEM pictures at different magnifications. The micrographs depict the hetero-materials' amalgamation, resulting in the formation of compacted particles that collectively exhibit a prominent bulbous morphology. The size and shape of different particles in the nanocomposites are visible from the FESEM images. The assays conducted by EDX have verified the presence of the necessary components, exhibiting a high degree of purity. Further insights about the nanocomposites have been obtained from Atomic Force Microscopy (AFM) analysis. AFM analysis revealed the surface roughness, which increased to 11.9 from 4.4 µm due to the addition of BN. The crystalline structure has been confirmed from the XRD analysis.

Structural, Morphological, Optical, and Magnetic Properties of NiO-added NiCo2O4 Electrode Materials Synthesized by Sol-Gel, Co-Precipitation and Ultrasonication Methods and their Electrochemical Supercapacitor Response

In this study, NiO-added NiCo2O4 composite samples were prepared using three distinct synthesis methods to study the impact of synthesis technique and NiO addition on the electrochemical performance of NiCo2O4. The chosen methods, sol-gel, co-precipitation, and ultrasonication, represent a range of approaches that yield different particle structures and morphologies. The structural and morphological studies of composite samples were investigated using X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM), respectively. XRD analysis revealed the crystalline composition, revealing the presence of two distinct phases: NiO and NiCo2O4. The Rietveld analysis of the composite samples supports the dual phases in the samples. FESEM analysis confirms the change in size and shape of the particles with the synthesis procedure. Optical properties, measured via UV-visible absorbance spectra, demonstrated that the energy gap varied with the synthesis method. The sol-gel samples exhibited the highest energy gap at 2.20 eV. The magnetic properties were measured using the vibration sample magnetometer (VSM), and the results confirm that the synthesis procedure influences magnetic loops and coercivity. The electrochemical performance of the samples in a 3 M potassium hydroxide electrolyte revealed that the co-precipitation method produced the highest capacitance of 398 Fg-1 at a 10 mV/s sweep rate, indicating superior energy storage capacity compared to pure NiCo2O4. Adding NiO phase to the NiCo2O4 matrix is believed to enhance electrochemical performance by creating additional charge at the grain boundaries, leading to a synergistic effect and improved electron and ion transport. The exceptional electrochemical performance of these composite materials suggests that the synthesis methods and the addition of NiO play a critical role in determining the overall efficiency and applicability of battery-type supercapacitors. These findings pave the way for further research into optimizing synthesis parameters to enhance energy storage capacity and inspire the development of advanced spinel metal oxide composite electrodes for supercapacitors and other energy storage applications.

Zinc-modified barium stannate micro-rods: Investigating structural, morphological, and optical features

In the present study, we have synthesized pristine and Zn-doped (0.025, 0.05, 0.075, 0.10) barium stannate (BSO) micro-rods via the hydrothermal method. The prepared samples have been analyzed for their structural, optical, and morphological properties using X-ray diffraction technique (XRD), UV–Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDX). Our Rietveld refinement examination of the XRD data verifies that the samples are single-phase, with a cubic crystal structure. Additionally, the lattice parameters determined align closely with the existing literature. Furthermore, the FE-SEM analysis unveiled the presence of well-defined rod-shaped structures accompanied by particle agglomeration across the surface. Further, the EDX analysis confirmed the presence of key elements, providing crucial insights into the material's chemical makeup. Especially noteworthy was the UV-DRS analysis, demonstrating a direct correlation between increased Zn doping concentrations and a concurrent reduction in the band gap values. This adjustment aligns the material's band gap with those commonly found in key components utilized in DSSC and PSC cells, suggesting promising applications in these crucial technological domains.

Electrochemical evaluation of hybrid La2CoCrO6/Co3O4/rGO composite for enhanced supercapacitor performance

The present work focuses on the synthesis of hybrid La2CoCrO6/Co3O4/rGO composite via solvothermal technique for supercapacitor application. X-ray diffraction, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda analyses are employed to assess phase structure, morphology, chemical state, surface area, and porosity of synthesized materials, respectively. The formation of mesoporous spheres is confirmed through FESEM and BET analysis. The inclusion of redox additive KMnO4 in KOH electrolyte enhances the accessibility of electrochemical sites in the mesoporous spheres of the La2CoCrO6/Co3O4/rGO electrode, resulting in excellent charge storage. Electrochemical analysis of the La2CoCrO6/Co3O4 exhibits specific capacitance of 633.2 F/g at 2 A/g in a redox electrolyte (6 M KOH + 0.05 M KMnO4) with capacitive retention of approximately 81 % over 5000 cycles. Furthermore, the addition of rGO improves the overall performance of La2CoCrO6/Co3O4/rGO composite (763.9 F/g at 2 A/g with capacitive retention of approximately 86 %). The electrochemical analysis of hybrid La2CoCrO6/Co3O4/rGO composite showed improved performance, owing to the synergy of double perovskite (La2CoCrO6), cobalt oxide (Co3O4), and reduced graphene oxide (rGO). These findings suggest promising applications for the material in advanced energy storage devices.

Effect of Starch Binders on the Properties of Bioglass Tablets for Bone Tissue Engineering Applications

AbstractThis study focuses on the synthesis and characterization of SiO2–CaO–P2O5–Na2O nanofiber bioglass (BG) tablets using cellulose nanofibers (CNFs) as a template and starch binders. Three types of tablets are prepared: sago starch binder tablets, xanthan gum binder tablets, and dry press tablets (used as a control). The tablets are investigated for their physicochemical structure, mechanical properties, in‐vivo bioactivity, and antibacterial efficiency using various characterization techniques such as Fourier transform infrared (FTIR), field emission scanning electron microscope (FESEM), XRD, ICP, etc. The results indicate the formation of a hydroxyapatite (HA) layer on the surface of the tablets after immersion in simulated body fluid (SBF) for 28 days, demonstrating their bioactivity. FESEM analysis reveals the formation of HA crystals with different morphologies, including oval‐shaped crystals in sago tablets and needle‐like crystals in xanthan tablets. The binder tablets exhibit higher Ca/P ratios compared to the press‐dried tablets. Among the binder tablets, sago starch tablets show superior mechanical properties. Additionally, the binder tablets display efficient antibacterial activity against Staphylococcus aureus and Escherichia coli bacteria. These findings highlight their potential as promising candidates for bone tissue engineering applications.

Green synthesis of silver nanoparticles using mature-pseudostem extracts of Alpinia nigra and their bioactivities

Abstract Green synthesis of silver nanoparticles (AgNPs) employing agricultural wastes as plant extracts to improve environmental benignity and also economic value added is the highlight of this research. The mature pseudostem of Alpinia nigra is an unbeneficial raw material discarded from several food ingredients and medicinal formulas. Therefore, this research focused on condition optimization for AgNP synthesis with ecofriendly techniques using A. nigra mature-pseudostem extracts and evaluation of their antioxidant, antibacterial activities, and toxicity with brine shrimp lethality assay (BSLA). The optimal reaction conditions were achieved by using 5 mM silver nitrate (AgNO3) solution with a volume ratio of 2:8 for the extract to AgNO3 at pH 12 under room temperature. The morphology and crystalline phase of the generated AgNPs were characterized using UV–visible spectrophotometry, field emission-scanning electron microscope (FE-SEM), energy dispersive X-ray, X-ray diffraction, and Fourier transform-infrared (FTIR) techniques. The FE-SEM analysis exposed spherical shapes with an average diameter of approximately 49 nm. The XRD analysis indicated their face center cubic structure, and the FTIR spectra confirmed that phytochemicals from A. nigra extract promoted the synthesis of AgNPs. In particular, the biosynthesized AgNPs presented potential antibacterial activity against both Staphylococcus aureus and Escherichia coli and effective antioxidant capacity using the DPPH radical scavenging assay. Additionally, non-toxic desired AgNPs were confirmed with BSLA.

Investigating morphological, optical and magnetic properties of blended novel ZnO-Ag/NiFe2O4 nanocomposite

Metal oxide nanoparticles and magnetic nanoparticles are combined to create magnetic nanocomposites (MNCs) with unique physical, chemical, and biological properties. A new ZnO-Ag/NiFe2O4 ternary magnetic nanocomposite was created in the current study using a simple and straightforward solid-phase mixing process with subsequent thermal treatment. The structural, optical, and magnetic properties of the ZnO-Ag/NiFe2O4 nanocomposite were studied using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDAX), vibrating sample magnetometry (VSM), and Raman spectroscopy. Brunauer–Emmett–Teller (BET) analysis was performed to analyze the surface area and average pore diameter of the nanocomposite. Cyclic voltammetry and photoelectrochemical analysis were performed to study the electrical behavior and charge carrier concentrations. According to XRD studies, the ZnO-Ag/NiFe2O4 nanocomposite is composed of the hexagonal wurtzite of ZnO and the spinel cubic structure of NiFe2O4. FESEM analysis revealed that the crystals of the nanocomposite were nearly spherical, and EDAX elemental mapping indicated that the elements were evenly dispersed across the sample without any impurities. The average diameter of the ZnO-Ag/NiFe2O4 nanocomposite obtained from the TEM images was nearly 50.65 nm. The specific surface area and average pore diameter of the ZnO-Ag/NiFe2O4 nanocomposite were 13.58 m2/g and 4.33 nm, respectively, according to BET analysis. CV analysis revealed a sharp increase in the specific capacitance of the ZnO-Ag/NiFe2O4 nanocomposite. The specific capacitances of the 1 M NaOH electrolyte, ZnO nanoparticles and ZnO-Ag/NiFe2O4 nanocomposite were 55.7302 F/g, 53.947 F/g, and 87.229 F/g, respectively, at a 0.05 V/s scan rate. With a coercive field (Hc) of 167 Oe, remnant magnetization (Mr) of 0.73 emu/g, and saturation magnetization (Ms) of 6.58 emu/g, the blended magnetic nanocomposite ZnO-Ag/NiFe2O4 exhibited superparamagnetic behavior at ambient temperature. Using an external permanent magnet, the ZnO-Ag/NiFe2O4 nanocomposite may be extracted from the reaction mixture, indicating its probable environmental and biomedical application.

Crocin-Phospholipid Complex: Molecular Docking, Molecular Dynamics Simulation, Preparation, Characterization, and Antioxidant Activity

Background: Crocin is a water-soluble carotenoid compound present in saffron (Crocus sativus L.), known for its wide range of pharmacological activities, including cardioprotective, hepatoprotective, anti-tumorigenic, anti-atherosclerosis, and anti-inflammatory effects. Objectives: The instability of crocin, its low miscibility with oils, and poor bioavailability pose challenges for its pharmaceutical applications. This study aimed to design and prepare a crocin-phospholipid complex (CPC) and assess its physicochemical properties. Methods: The study investigated the formation of the complex and its binding affinity through molecular docking. Molecular dynamics (MD) simulations were conducted to find the optimal molar ratio of crocin to phospholipid for the complex's preparation. The CPC was produced using the solvent evaporation method. Techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), nuclear magnetic resonance (NMR), and solubility studies were utilized to characterize and confirm the formation of CPC. Additionally, the in vitro antioxidant activity of crocin and CPC was evaluated. Results: Molecular dynamic simulations explored molar ratios of 1: 1, 1: 1.5, and 1: 2 for crocin to phospholipid. The ratio of 1: 2 was found to be the most stable, exhibiting the highest probability of hydrogen bond formation. Molecular docking, FTIR, and NMR studies indicated hydrogen bond interactions between crocin and phospholipid, confirming CPC's formation. XRD and FE-SEM analyses showed a decrease in crocin's crystallinity within the phospholipid complex. Furthermore, the solubility of crocin in n-octanol was enhanced post-complexation, indicating an increase in crocin's lipophilic nature. Conclusions: Phospholipid complexation emerges as a promising technique for enhancing the physicochemical characteristics of crocin.

Green synthesis of silver and gold nanoparticles in Callistemon viminalis extracts and their antimicrobial activities.

In the current study, the bottlebrush [Callistemon viminalis (Sol. ex Gaertn.) G. Don] plant was selected for the green synthesis of silver (Ag) and gold (Au) nanoparticles and to evaluate its antibacterial and antifungal activities. Phytochemical screening of C. viminalis confirmed the presence of alkaloids, anthraquinones, saponins, tannins, betacyanins, phlobatanins, coumarins, terpenoids, steroids, glycosides, and proteins. To characterize the synthesized Ag and Au NPs, UV-Visible spectroscopy, FTIR spectroscopy for functional group identification, field emission scanning electron microscopy (FE-SEM) for particle size, and elemental analysis were performed using EDX. The UV-Visible absorption spectra of the green-synthesized Ag and Au nanoparticles were found to have a maximum absorption band at 420 nm for Ag NPs and 525 nm for Au NPs. FE-SEM analysis of the synthesized NPs revealed a circular shape with a size of 100 nm. Elemental analysis was performed for the synthesis of Ag and Au NPs, which confirmed the purity of the nanoparticles. The greenly synthesized Ag and Au NPs were also evaluated for their anti-bacterial and anti-fungal activities, which exhibited prominent inhibition activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, C. krusei, Aspergillus sp., and Trichoderma species. The highest zone of inhibition 15.5±0.75 and 15±0.85mm was observed for Ag NPs against E. coli and P. aeruginosa. Similarly, Trichoderma sp. and Aspergillus sp. were inhibited by Ag NPs up to 13.5±0.95 and 13±0.70mm. This work will open doors for the development of new antimicrobial agents using green chemistry.

Electrochemical Behaviour of Ultrasonic Probe Assisted Nickel Pyrophosphate (Ni2P2O7) Nanosheets for Supercapacitor Applications

New materials and synthesis strategies are needed to achieve better electrochemical performance. In this context, we developed a Ni2P2O7 Nanosheets (NNS) as a new classical-type active electrode using a simple and low-cost method. Crystal phase, chemical structure, and morphology of the sample were inspected by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Field Emission Scanning Electron Microscopy (FESEM) - Energy Dispersive Spectroscopy (EDS) analysis, respectively. As prepared electrode material was confirmed with monoclinic phase and nanosheet morphology identified from XRD and FESEM analysis, respectively. Various types of electrochemical approaches, such as CV, GCD, Cycling stability, and EIS applied in 2 M KOH electrolytes to investigate supercapacitive behaviour. As fabricated electrode material portrays satisfied specific capacitance (Cs) of 514.7F/g at a scan rate of 1 mV/s along with the excellent cyclic ability of 80 % retention upon 3000 continuous CV cycles, good rate capability in the extended potential window of 1 V. The GCD tests revealed remarkable specific capacity (462C/g) and exceptional energy density (64 Wh/Kg). Moreover, electrode material displayed impressive columbic efficiency as to be 77 % and 51 % at lower and higher current densities, respectively. These notable merits suggest that our designed Nanosheets (NNS) sample is the best opportunity for the development of sustainable supercapacitor devices.

CHARACTERISATION, EVALUATION AND DENSITY FUNCTIONAL ANALYSIS OF CILNIDIPINE-NICOTINAMIDE COCRYSTALS DEVELOPED BY LIQUID ASSISTED GRINDING TECHNIQUE: A SUSTAINABLE APPROACH FOR ENHANCED SOLUBILITY

Objective: Improving the solubility of poorly water-soluble drugs has always been a challenge in drug development. This study aimed to enhance the aqueous solubility of a poorly water-soluble drug, Cilnidipine, by cocrystallisation method using liquid-assisted grinding (LAG) technique with Nicotinamide as the coformer. The study also aimed to understand the mechanism of cocrystal formation by quantum mechanical calculations. Methods: The Cilnidipine-Nicotinamide cocrystals were prepared in various stoichiometric ratios using the liquid-assisted grinding (LAG) technique. The cocrystals obtained were characterised by vibrational spectroscopy, thermal methods such as differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and surface morphology by field emission scanning electron microscopy (FE-SEM). The cocrystals were evaluated for saturation solubility, and the mechanistic study of cocrystal formation was performed using the Gaussian 09 software package. Results: FT-IR spectra of the formulated cocrystal indicated the intermolecular hydrogen bond formation between-N-H of Nicotinamide and the nitro group of Cilnidipine. DSC analysis showed a single endotherm at 96.76 °C, PXRD patterns were different from that of the reactants, and FE-SEM analysis revealed the changes in the surface morphology of the obtained cocrystal. The prepared cocrystal showed a 26.36-fold enhancement in the aqueous solubility of Cilnidipine. The DFT study demonstrated the formation of a strong intermolecular hydrogen bonding between the nitro-oxygen atom of Cilnidipine and the amide hydrogen atom of Nicotinamide in cocrystal formed. Conclusion: This study highlights the potential of the liquid-assisted grinding method for preparing cocrystals as a sustainable and reliable approach to address the challenges posed by poorly water-soluble drugs.

Structural and Morphological Characterization of MEH-PPV/Ag Composite

In this study, spin coating was used to prepare thin films of poly (2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylene vinylene) and silver (MEH-PPV/Ag) in this study. The physical characteristics of MEH-PPV/Ag thin films with various weight ratios (0.01, 0.02, 0.03, and 0.04%) were investigated by Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction analysis (XRD), and thermal testing. FTIR analysis showed that there were occurrences of the polymer's predicted chemical bonds. AFM tests show that when different amounts of silver are added to a polymer matrix, the film's surface roughness (root mean square) goes up from an average of 83.51 to 511.3 nm. FE-SEM analysis showed that a pure sample of the polymer formed evenly. However, when different amounts of Ag were added, clear balls or circles formed, showing the energy of mixing between the MEH-PPV and Ag. As silver addition transformed the polymer from amorphous to polycrystalline, XRD analysis revealed both phases. In tests comparing pure MEH-PPV to MEH-PPV/Ag, the polymer containing silver showed higher thermal conductivity.

Thiol‐ene click chemistry for constructing transition layer to enhance the interface interaction between polyacrylonitrile fiber and styrene‐butadiene‐styrene modified asphalt

AbstractBased on the high chemical stability and excellent end‐group functionalization capability of polyhedral oligomeric silsesquioxane (POSS), this study utilized thiol‐functionalized POSS (POSS‐SH) in a click chemistry reaction with styrene‐butadiene‐styrene triblock copolymer (SBS). The objective was to design a functional group forming a chemical bond with the polymer matrix, resulting in the preparation of thiol‐functionalized polyacrylonitrile (PAN) fibers chemically cross‐linked with POSS‐SH/PAN/SBS hybrid material. This hybrid material not only enhanced the compatibility between the components but also facilitated a connection between the fiber and SBS, thereby improving the mechanical properties of the modified asphalt. Fourier transform infrared spectroscopy, field emission scanning electron microscopy (FESEM), and atomic force microscopy analyses confirmed the successful modification of POSS‐SH/PAN fibers. FESEM analysis of the modified asphalt verified that POSS‐SH/PAN fibers contributed to strengthening the interfacial performance between the fiber and asphalt. Cone penetration and dynamic shear rheometer tests indicated that, compared to SBS‐modified asphalt, PAN/SBS and POSS‐SH/PAN/SBS‐modified asphalt exhibited enhanced shear strength, deformation resistance, and viscoelastic properties. Additionally, at 46°C, the storage modulus (G′) of 1.5% POSS‐SH/PAN/SBS‐modified asphalt increased by 11% compared to 1.5% PAN/SBS asphalt, with increases of 13.75% and 10.8% in loss modulus (G″) and complex modulus (G*), respectively.

Enhanced electrocatalytic activity of bismuth-doped lanthanum stannate pyrochlore for electrochemical detection of the Covid-19 drug nitazoxanide

Nitazoxanide (NAZ) is an antiparasitic drug that reduces inflammation caused by the SARS-CoV-2 virus. The presence of nitro group in this drug makes it an environmental pollutant. Here, an electrochemical sensor for the determination of NAZ was developed based on bismuth-doped pyrochlore lanthanum stannate nanoparticles modified screen-printed carbon electrodes (BLSO NPs/SPCE). The BLSO NPs were prepared by a combination of co-precipitation and thermal calcination processes. The fabricated BLSO NPs were analyzed by different spectroscopic methods. X-ray diffraction analysis (XRD), Fourier transform-infrared spectroscopy (FT-IR), and Raman spectroscopy showed that the lattice parameters of the lanthanum stannate nanoparticles (LSO NPs) were increased after bismuth doping due to cell expansion. The morphology and oxidation state of the elements in the BLSO NPs were analyzed by field emission-scanning electron Microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS). FE-SEM and HR-TEM analysis revealed that LSO, and BLSO exhibits as a nanoparticle morphology with 20–50 nm in size. Cyclic voltammetry (CV) showed that the electrochemical reduction of NAZ was enhanced after bismuth doping due to the synergistic effect of BLSO NPs. Electrochemical determination of NAZ was performed by DPV with a low detection limit of 4 nM between the linear range of 0.01–172 µM and an electrode sensitivity of 0.16 µA µM−1 cm−2. The developed NAZ sensor showed favorable results in terms of selectivity, repeatability, and stability.

Probing the interaction behavior of Nano-Resveratrol with α-lactalbumin in the presence of β-lactoglobulin and β-casein: spectroscopy and molecular simulation studies

The main purpose of this research was to evaluate the role of α-lactalbumin (α-LA), β-lactoglobulin (β-LG), and β-Caseins (β-CN) in the binding interaction between Nano Resveratrol (Nano Res), as binary and ternary systems. This investigation was fulfilled through the application of multi-spectroscopic, transmission electron microscopy (TEM), field emission scanning electron microscope (FE-SEM), conductometry, isothermal titration calorimetry (ITC), and molecular dynamics (MD) simulation techniques. Fluorescence spectroscopy observations illustrated the effectiveness of Nano Res throughout the quenching of α-LA, (α-LA-β-LG), and (α-LA-β-CN) complexes, confirming the occurrence of interaction through the combination of static and dynamic mechanisms. An enhancement in the temperature of all three complexes caused a decrease in their Ksv and Kb values, which indicates the static and dynamic behavior of their interactions. The obtained thermodynamic parameters proved the dominance of electrostatic interaction as the binding force of both binary and ternary systems. The observed properties of Tyr or Trp residues in proteins through the data of synchronous spectroscopy at Δλ = 15 and 60 nm, respectively, demonstrated the closer positioning of (α-LA-β-CN) complex to the proximity of Trp residues when compared to the two other cases. According to the resonance light scattering (RLS) measurements, the detection of a much greater RLS intensity in (α-LA-β-CN) Nano Res complex suggested the production of a larger complex. Furthermore, the conductometry outcomes displayed an increase in molar conductivity and therefore approved the occurrence of interaction between Nano Res and proteins in both binary and ternary systems. The spherical shape of Nano Res was confirmed through the results of FE-SEM and TEM analyses. The conformational changes of proteins throughout the binding of Nano Res was evaluated by circular dichroism (CD) technique, while molecular docking and MD simulations affirmed the binding of Nano Res to α-LA, (α-LA-β-LG), and (α-LA-β-CN) complexes as binary and ternary systems. These In Silico study data confirm the results of in vitro assessments. The occurrence of changes in the secondary structure of β-galactosidase was implied through the increased enzyme catalytic activity induced by the interaction of different lactose concentrations. Communicated by Ramaswamy H. Sarma

Green synthesis, characterisation, and performance evaluation of ZnO/TiO2 nanocomposite for cationic and anionic dye removal from aqueous solutions under solar irradiation

Abstract Utilising plant extract for the synthesis of nanocomposite shows great potential as a viable substitute for conventional chemical method. In this study, ZnO/TiO2 composite of three different weight ratios (1:2, 1:1, and 2:1) were green synthesised using hibiscus leaf extract as the capping agent. The synthesised composites were characterised using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), UV–Vis Diffuse Reflectance Spectroscopy (UV–Vis DRS), Energy Dispersive X-ray Spectrometer (EDS), and Fourier Transform Infrared Spectroscopy (FTIR). XRD results confirmed the presence of wurtzite ZnO and anatase TiO2 in the composite. FTIR and FESEM analysis confirmed the formation of the composite. The composite was used for the removal of methylene blue and methyl orange dye under solar radiation. The degradation rate constant (k) of the composite with 1:2 weight ratio was 1.9 times the k value of pure TiO2. The effect of photocatalyst amount, initial pH of the dye solution, and reusability of the catalyst was investigated. The TiO2 and ZnO/TiO2 samples indicated a bandgap of 3.14 and 2.98 eV, respectively, which suggests better photocatalytic activity and also making the composite more active in the visible region.

Effects of rare-earth Pr3+-Dy3+ doping on structural, magnetic, optical and dielectric properties of Zn2Y hexaferrite

This study was conducted to investigate the properties of Pr3+-Dy3+ doped Zn2Y-type hexaferrite for potential technological applications. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM) were used to analyze structural properties. The crystallite size in the synthesized samples varies between 57.54 and 68.57 nm. The vibrational bands at 400 and 600 cm−1, common to all hexaferrites, were confirmed through FTIR. The FESEM analysis reveals an agglomeration of magnetic grains and a decrease in the average grain size from 1.24 to 1.06 μm. The M-H loops show that, with x values of 0.0, 0.1, and 0.2, the saturation magnetization is determined to be 34.76, 34.23, and 32.52 emu/g, respectively. The corresponding coercivity values are 21.24, 30.39, and 33.99 Oe. UV–visible spectroscopy using Tauc theory reveals an increase in the optical band gap from 2.32 to 2.50 eV, indicating a tunable energy band structure by incorporating Pr3+-Dy3+ ions. The dielectric constant increases, whereas AC conductivity decreases with increased Pr3+-Dy3+ concentration. The obtained results suggest the potential suitability of these materials for various technological applications.

Colloidal stability and dielectric behavior of eco-friendly synthesized zinc oxide nanostructures from Moringa seeds

This study centers on the environmentally benign synthesis of zinc oxide nanoparticles (ZnO NPs) derived from Zn (CH3COO)2·2H2O and Moringa seeds. The synthesized nanostructures underwent comprehensive characterization utilizing diverse analytical techniques, encompassing X-ray diffraction (XRD), UV–VIS spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. XRD measurements coupled with W–H plot transformation unequivocally confirmed the formation of ZnO nanostructures, characterized by an average size of 24.9 nm. UV–VIS spectroscopy, complemented by Kubelka Munk curve analysis, elucidated the direct conduction and determined a bandgap of 3.265 eV. FESEM analysis revealed minimal particle aggregation, showcasing well-defined grain boundaries spanning sizes from 20.4 to 87.7 nm. XPS analysis substantiated the presence of Zn (2p), Zn (3p), Zn (3d), and O (1s). Raman spectroscopy identified E2H as the predominant mode, followed by E1(TO) and (E2H-E2L). ZnO thin films, fabricated via pulsed laser deposition (PLD) and deposited onto silicon (100) substrates, exhibited exemplary morphology and discernible topography, characterized by a normal grain size distribution. Zeta potential tests yielded a value of approximately (z\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcalligra{z}$$\\end{document} ~ − 43.8 mV), indicative of the commendable stability of the colloidal suspension, likely attributable to low particle aggregation. Dielectric measurements conducted on sintered pellets at 900 °C unveiled elevated capacitance and dielectric constant at low frequencies across the temperature range of 289.935–310 K. These findings affirm the potential utility of environmentally synthesized ZnO for a spectrum of applications, including energy devices and nanofluids.

Vacuum-evaporated PbS:0.03 Zn thin films with varying thicknesses for environmental applications

In this research, we explore how the thickness of PbS-doped Zn thin films made through thermal vacuum evaporation affects their physical properties for environmental applications. Our x-ray diffraction (XRD) examination shows that the films consist of pure crystalline cubic PbS phase. Additionally, the energy-dispersive X-ray spectroscope (EDXS) provides confirmation that the synthesized products are of high purity. PbS films doped with Zn have spherical nanocrystals ranging from 130 nm to 250 nm in size, as observed through field emission (FE)-scanning electron microscopy (FE-SEM) analysis. The thickness of the film layer was found to correlate significantly with an increase in crystallite size and grain size, as validated by both XRD and FE-SEM analyses. The optical energy gap (Eg) of the thin films under examination exhibited variations in relation to their respective thickness. Bandgap energy was found to decrease from 1.66 eV to 1.2 eV as film thickness was increased from 50 nm to 250 nm. The Arrhenius law shows that films with varying thicknesses have thermally activated electrical conductivity and exhibit two conduction mechanisms. After analyzing the photocatalytic decomposition of methylene blue, it was observed that a thicker (PbS)0.97(Zn)0.03 film with a larger grain size demonstrated superior photocatalytic efficiency (92 % after an exposure duration of 180 min). This is due to a smaller band gap and the presence of defect sites, which enhance catalytic reactions. The study presents a framework for researching the controllable structure, thickness, and composition of chalcogenide semiconductor thin films for environmental applications.