Ultraviolet-visible Spectroscopy Research Articles

Enhanced performance of Mg and La co-doped TiO2(98%)−ZrO2(2%) photoanode for dye-sensitized solar cells

Abstract This study explores the effects of magnesium (Mg) and lanthanum (La) doping on the performance of dye-sensitized solar cells (DSSCs) utilizing TiO2(98%)−ZrO2(2%) (TZ, TZM, and TZL) photoanodes. The photoanodes were fabricated using a spin-coating sol–gel method, followed by calcination at 400°C. The structural, morphological, crystallographic, and optical properties of the proposed photoanode composites were characterized by X-ray diffraction, transmission electron microscopy, and ultraviolet–visible spectroscopy. The crystallite sizes of the synthesized thin films varied from 21.16 to 59.04 nm for the TZ, TZM, and TZL compositions. The current–voltage measurements of DSSCs based on TZL8 photoanode, cobalt sulfide-doped graphene counter electrode, and N719 dye revealed the highest efficiency of nearly 5.052%. The assembled DSSCs exhibited an open-circuit voltage of 0.74 V, a short-circuit current density of 9.964 mA/cm2, and a fill factor of 0.685. The enhancement in open-circuit voltage and short-circuit current density could be attributed to the improved electronic and microstructures of the proposed photoanodes.

Low thickness effect on the properties of Mn-doped ZnO thin films synthesized by sol-gel spin coating technique

In this study, 7% manganese-doped zinc oxide (MZO) thin films with varying low thicknesses were synthesized using the spin coating method. The structural, optical, and morphological properties of MZO films with different film thickness, were systematically investigated. The crystallite structure, superficial morphology, and optical characteristics were analyzed using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and ultraviolet–visible spectroscopy (UV-Vis). Structural analysis confirmed that all films exhibit a hexagonal wurtzite phase with a pronounced peak along the c-axis, and slight variation in low thickness significantly affected the structural parameters. The surface morphology demonstrated good uniformity, characterized by rounded grain shapes in the plane, while surface roughness was found to be increased with increasing film thickness. Optical analysis revealed that as the number of coatings increased, both transmittance and band gap energy decreased, accompanied by a redshift in the absorption edge across all samples. This behavior is attributed to light scattering, as well as an increase in the refractive index and dielectric function with visible light energy, influenced by the number of layers and corresponding crystallite size.

Synthesis, Characterization, Density Functional Theory Study, Antibacterial Activity and Molecular Docking of Zeolitic Imidazolate Framework‐8

ABSTRACTIn this study, Zeolitic Imidazolate Framework‐8 (ZIF‐8) nanomaterials were synthesized using a co‐precipitation one‐pot method that uses ethanol, methanol, and water as solvents for the precursors (2‐methylimidazole and Zinc nitrate hexahydrate), resulting in yields of 66.77%, 73.14%, and 68.12%, respectively. The as‐synthesized ZIF‐8 nanomaterials were thoroughly characterized by X‐ray diffraction analysis, transmission electron microscopy, ultraviolet–visible spectroscopy, and Fourier‐transform infrared spectroscopy. The X‐ray diffraction analysis showed that the crystallite size of ethanol‐based ZIF‐8 (24.76 ± 1.67 nm) was smaller than those synthesized in water (26.92 ± 1.89 nm) and methanol (31.39 ± 1.03 nm). However, methanol‐based ZIF‐8 exhibited lower crystallinity (85.93%) than water‐based ZIF‐8 (91.48%) and ethanol‐based ZIF‐8 (92.71%). Zeta potential studies revealed that ethanol‐based ZIF‐8 had a larger surface charge (+37 mV) than water‐based ZIF‐8 (+35 mV) or methanol‐based ZIF‐8 (+24 mV). Transmission electron microscopy analysis confirmed particle sizes of 54.35 ± 2.11 nm for ethanol‐based ZIF‐8, 57.91 ± 2.26 nm for water‐based ZIF‐8, and 63.25 ± 4.12 nm for methanol‐based ZIF‐8. Thermogravimetric analysis indicated thermal stability up to 800 °C, with mass losses of 55.98% for ethanol‐ZIF‐8, 50.12% for water‐based ZIF‐8, and 65.36% for methanol‐based ZIF‐8 by 600 °C. In antibacterial studies, water‐based ZIF‐8 exhibited the largest zone of growth inhibition (17.30 ± 0.26 mm) against Escherichia coli compared to ethanol‐based ZIF‐8 (15.57 ± 0.32 mm) and methanol‐based ZIF‐8 (14.70 ± 0.20 mm). Pearson's correlation study revealed that zeta potential, crystallinity, and antibacterial activity are positively related. Furthermore, water‐based ZIF‐8, with a minimum inhibitory concentration of 50 μg/100 μL, confirmed evident cell membrane disruption. Molecular docking experiments revealed ZIF‐8's significant binding affinity for the E. coli protein 5AZC, supporting its robust antibacterial activity.

Photocatalytic Degradation of Four Organic Dyes Present in Water Using ZnO Nanoparticles Synthesized with Green Synthesis Using Ambrosia ambrosioides Leaf and Root Extract

Currently, several organic dyes found in wastewater cause severe contamination problems for flora, fauna, and people in direct contact with them. This research proposes an alternative for the degradation of polluting dyes using ZnO nanoparticles (NPs) synthesized by an ecological route using leaf and root extracts of Ambrosia ambrosioides as a reducing agent (with a weight/volume ratio = 4%). Scanning Electron Microscopy (SEM) was used to determine the morphology, showing an agglomeration of cluster-shaped NPs. Using Transmission Electron Microscopy (TEM), different sizes of NPs ranging from 5 to 56 nm were observed for both synthesized NPs. The composition and structure of the nanomaterial were analyzed by infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), showing as a result that the NPs have a wurtzite-like crystalline structure with crystallite sizes around 32–37 nm for both samples. Additionally, the bandgap of the NPs was calculated using Ultraviolet Visible Spectroscopy (UV–Vis), determining values of 2.82 and 2.70 eV for the NPs synthesized with leaf and root, respectively. Finally, thermogravimetric analysis demonstrated that the nanoparticles contained an organic part after the green synthesis process, with high thermal stability for both samples. Photocatalytic analysis showed that these nanomaterials can degrade four dyes under UV irradiation, reaching 90% degradation for methylene blue (MB), methyl orange (MO) and Congo red (CR) at 60, 100 and 60 min, respectively, while for methyl red (MR) almost 90% degradation was achieved at 140 min of UV irradiation. These results demonstrate that it is effective to use Ambrosia ambrosioides root and leaf extracts as a reducing agent for the formation of ZnO NPs, also evidencing their favorable application in the photocatalytic degradation of these four organic dyes.

Maillard reaction-based conjugation of pea protein and prebiotic (polydextrose): optimization, characterization, and functional properties enhancement

There is a growing demand for plant-based protein ingredients with improved functionality for use in diverse food and nutraceutical applications. In line with this, the current study aimed to investigate the effect of plant protein-prebiotic (polydextrose) conjugation on the techno-functional properties (emulsification, solubility, fat absorption and foaming) of pea proteins through wet heating Maillard reaction. Pea protein (PeP) was conjugated with polydextrose by incubating the mixture at various process conditions (pea protein: polydextrose mass ratios, temperature, and time). Response surface methodology coupled with Box–Behnken design was used to optimize multiple responses, including conjugation efficiency (CE), emulsifying activity (EAI), and foaming capacity (FC). The pea protein conjugate (optimized value) showed improved solubility throughout a wide pH (2–10) range and higher emulsification activity than pea protein alone. The development of conjugates (PeC) was validated through ultraviolet–visible spectroscopy, FTIR, and o-Phthaldialdehyde (OPA) assay. Browning index, FT-IR spectra, thermal properties, and scanning electron microscopy (SEM) micrographs were analyzed for the conjugate (PeC) obtained at optimized values. The FTIR spectra of the conjugates showed new peaks at 3100–3480 cm−1 and 1,000–1,166 cm−1 indicating conjugation. The Maillard conjugation increased the proportion of β-turn, random coil, accompanied by a decrease in α-helix, and β-sheet. These conformational changes were associated to the improved techno-functional properties of the pea protein upon conjugation, offering potential applications in the formulation of plant-based foods and beverages.

Screening and inclusion of luteolin for β-cyclodextrin: molecular simulations and experiments

In this study, we first established a guest small molecule screening mechanism by molecular simulation, and then screened lignans from 10 polyphenolic compounds to identify the most suitable guest molecule for encapsulation with β-cyclodextrin (β-CD). Subsequently, the subject-guest interactions and encapsulation mechanisms of lignans with β-CD, 2-hydroxypropyl-cyclodextrin (HP-β-CD) and 2,6-dimethyl-cyclodextrin (DM-β-CD) were investigated using a combination of molecular simulation and experimental methods, respectively. Molecular simulations were performed to calculate the microstructural parameters, including solubility parameters, binding energies, and mean square displacements. The simulation results demonstrated that DM-β-CD exhibited the strongest interaction with luteolin and formed the most stable inclusion complex. The inclusion complexes of luteolin with the three cyclodextrins were prepared by freeze-drying method, and the formation of the inclusion complexes was demonstrated using infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and ultraviolet-visible spectroscopy (UV). Phase solubility studies confirmed the formation of 1:1 stoichiometric inclusion complexes of lignans with cyclodextrins. Furthermore, 2,2-diphenyl-1-pyridine hydrazine (DPPH) free radical scavenging experiments demonstrated that the inclusion complexes exhibited enhanced antioxidant capacity. In light of these findings, it can be concluded that among the three cyclodextrins, DM-β-CD was optimally encapsulated with luteolin.

Novel Photobase Generators Derived from Proazaphosphatrane–Aryl Borate for High‐Pressure Mercury Lamp Lithography

AbstractHerein, novel borate‐type photobase generators (PBGs) that generate a proazaphosphatrane known as Verkade's base (2,8,9‐triisobuthyl‐2,5,8,9‐tetraaza‐1‐phosphabicyclo[3.3.3]undecane (TTP)) were developed for photopatterning using a high‐pressure mercury lamp. Eight PBGs were synthesized, each featuring distinct borate substituents: phenyl, p‐fluorophenyl, p‐tolyl, p‐methoxyphenyl, m‐fluoro‐p‐methylphenyl, 4‐biphenyl, 2‐naphthyl, and 6‐methoxy‐2‐naphthyl. The relation between these substituents and their light absorption characteristics was analyzed via ultraviolet–visible spectroscopy and time‐dependent density functional theory calculations. The PBG with the 6‐methoxy‐2‐naphthylborate group (TTP–tetrakis[2‐(6‐methoxynaphthyl)]borate (TTP–TMNB)) demonstrated substantial light absorption near 365 nm (the i‐line of the high‐pressure mercury lamp), generating approximately 60 % of the corresponding TTP in deuterated tetrahydrofuran (THF) upon exposure to 650 mJ/cm2, as confirmed via 1H nuclear magnetic resonance spectroscopy. To evaluate its photolithographic potential, TTP–TMNB was mixed with epoxy resin (jER1001) and a poly(methacrylic acid)‐co‐poly(methyl methacrylate) copolymer (PMA1.6‐co‐PMMA100) in THF. The resulting mixture was spin‐coated onto a silicon wafer and irradiated with the i‐line through a photomask to create a negative‐tone image. The sensitivity and contrast of this photopolymer system were measured to be 45 mJ/cm2 and 1.0, respectively; moreover, a clear 10‐μm negative‐tone resolution was achieved.

PH-sensitive polymeric hydrogels coated with cobalt ferrite nanoparticles for combined drug delivery as controlled release carriers: fabrication and in-vitro estimation

In this investigation, we produced pH-responsive hydrogels for the controlled release of drugs by graft copolymerizing Gum ghatti and acrylic acid (AA) in an aqueous medium. N, N′-methylene-bis-acrylamide (MBA) and ammonium persulphate (APS) served as cross-linkers during the synthesis process. Our research explores the integration of cobalt ferrite (CoFe2O4) magnetic nanoparticles (CFMNPs) in delivering a combination drug comprising metformin hydrochloride and sodium diclofenac. The diverse applications of CoFe2O4 nanoparticles have driven the exploration of innovative and environmentally sustainable production methods. The development of novel materials for nanoparticle synthesis adheres to the principles of “Green Chemistry” through a co-precipitation technique. Characterization of the cross-linked hydrogels involved Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses. In vitro drug release kinetics were observed under physiological conditions using Ultraviolet–Visible Spectroscopy. The drug-loaded Gg-cl-poly(AA)/CoFe2O4 hydrogels exhibited a sustained drug release profile over 24 h, with significant release occurring at a pH of 4. To comprehend the drug release mechanism, we employed kinetic modeling, encompassing Zero order, First order, Higuchi model, Hixson-Crowell model, and Korsmeyer-Peppas model, for all developed hydrogels. The findings indicated that the drug release mechanism from the hydrogels followed the Korsmeyer-Peppas model. The study concludes that the developed hydrogel offers a promising solution for the controlled administration of metformin hydrochloride and diclofenac sodium.Graphical

Structural and Textural Characteristics of Municipal Solid Waste Incineration Bottom Ash Subjected to Periodic Seasoning

The objective of this study was to determine the structural and textural description of municipal solid waste incineration (MSWI) bottom ash that was subjected to a six-month seasoning process. Bottom ash samples, with a particle size fraction of 0.063–0.1 mm, were seasoned in a closed landfill and collected for laboratory analyses at monthly intervals. The research focused on determining the structural parameters, using methods such as nuclear magnetic resonance spectroscopy (1H NMR), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), and the textural parameters, using low-pressure nitrogen adsorption (LPNA) at −196.15 °C. The analyses of the porous structure of the bottom ash samples revealed differences in texture of ASH 1 to ASH 6, specifically in the pore volume (micro- and mesopores), specific surface area, and pore size distribution. Changes in the structural and porous characteristics of the samples were attributed to the duration of the seasoning process. The results of the structural analysis of the bottom ash suggest its application in the concrete industry, potentially enhancing the long-term mechanical strength of concrete. The results of the textural analysis indicate the possible use of MSWI bottom ash in environmental applications, as the internal surface area could be further developed.

LITERATURE REVIEW ON HPLC METHODS FOR ESTIMATION OF EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE TABLETS

Emtricitabine and Tenofovir Disoproxil Fumarate (TDF) are essential components of antiretroviral therapy (ART) for HIV infection. Accurate quantification of these drugs in pharmaceutical formulations is crucial for ensuring therapeutic efficacy and patient safety. High-Performance Liquid Chromatography (HPLC) is a widely used analytical technique for this purpose. Several validated HPLC methods have been developed, employing diverse chromatographic conditions and detection techniques. These methods typically utilize reversed-phase C18 columns and UV detection at 260 nm or 270 nm. Key considerations for method development include selectivity, sensitivity, accuracy, precision, linearity, and robustness. Additionally, other analytical techniques such as UltraHigh Performance Liquid Chromatography (UHPLC), Thin-Layer Chromatography (TLC), Fourier Transform Infrared Spectroscopy (FTIR), and Ultraviolet-Visible (UV-Vis) Spectroscopy have been explored for the analysis of Emtricitabine and TDF. However, HPLC remains the preferred method due to its versatility, sensitivity, and reliability.

Multiscale Analyses of Strain-Enhanced Charge Transport in Conjugated Polymers.

The advancement of flexible and wearable electronics relies on semiconducting polymers that can endure mechanical deformation while maintaining high electrical performance under strain. In this study, we demonstrate that fine-tuning backbone rigidity through the molecular design of donor moieties significantly enhances both the mechanical and charge transport properties of diketopyrrolopyrrole (DPP)-based polymers. Specifically, the flexible DPP-4T (quaterthiophene) exhibited a persistence length of 20.4 nm in solution, while DPP-DTT (dithienothiophene) showed a longer persistence length of 32.8 nm due to its stiff backbone, as confirmed by small-angle neutron scattering and Monte Carlo simulations. This flexibility enabled DPP-4T to achieve a crack-onset strain exceeding 100% via the film-on-elastomer method and a fracture strain of over 30% in quasi-free-standing films. Additionally, DPP-4T demonstrated a 180% increase in hole mobility at 80% strain, driven by strain-induced chain alignment and backbone planarization. Utilizing a range of characterization techniques, including ultraviolet-visible (UV-vis) spectroscopy, grazing incidence X-ray diffraction (XRD), and Raman spectroscopy, we characterized structural changes at multiple length scales under applied tensile strain. Notably, strain induced a transformation in chain conformation from a twisted to a flat structure, reducing the hopping energy barrier and enhancing charge transport. These structural rearrangements are crucial for sustaining efficient charge transport and ensuring the reliability of electronic performance under mechanical stress.

Optoelectronic properties of Mg and Cu co-doped ZnO nanostructure

In this work, both pure and Mg-Cu co-doped zinc oxide thin films are prepared by sol-gel spin coating technique. Microscopic glass substrates are used for the synthesis of thin films. The thin films are examined by X-ray spectroscopy (XRD), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-Vis), and energy dispersive X-ray analysis (EDX). The XRD reveals the hexagonal wurtzite phase of the films. The observed grain size is 23.34 nm to 15.94 nm for pure and Mg-Cu co-doped ZnO respectively. The SEM image shows an increase in grain size and a smoothing of the surface with Mg-Cu co-doping. The presence of Mg and Cu in the ZnO nanofilm is confirmed by EDX analysis. UV analysis shows an increase in percent transmittance with doping. The Tauc relation is used to estimate the band gap of the samples, and a significant shift in the band gap is observed. The photoluminescence diagram shows greater emission and surface defects with doping. The visible spectrum is completely covered by the low- level emission.

Insight into Antiviral Activity of Ag/TiO2 Nanocomposites Against Influenza H1N1 Virus and Its Antiviral Mechanism.

Synthesis and characterization of silver (Ag)/titanium dioxide (TiO2) nanocomposite (ATA) to investigate its antiviral activity against the H1N1 influenza virus and antiviral mechanisms. A water-dispersible ATA was prepared by a photocatalytic reduction process from AgNO3 and TiO2. The characterization of ATA was performed by ultraviolet-visible spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. The antiviral activities and the antiviral mechanism of ATA were investigated in detail by light microscopy, transmission electron microscopy and biological techniques such as cell cytotoxicity, 50% tissue culture infectious dose detection, western blot and reverse transcription-polymerase chain reaction. These results showed the successful synthesis of ATA nanocomposite with uniform particle size and distribution. It demonstrated the highly efficient antiviral activity of ATA in a dose- and time-dependent manner, as indicated by the reduction of viral titer and the reduction of cytopathic effects caused by viral infection. In the presence of ATA, the structure of the H1N1 influenza virus is directly destroyed and even disintegrated, with the damaged surface membrane proteins and fuzzy contour. It reduces the infection efficiency of influenza by suppressing the activity and expression of hemagglutinin and neuraminidase. The results of mechanistic studies suggested that ATA nanocomposite primarily interferes with virus attachment to viral receptors on the cell surface. Our study suggests that ATA may be a good antiviral candidate against the influenza virus. Compared with AgNPs alone, our synthesized ATA nanocomposites can achieve similar viral inactivation rates using only a much smaller concentration of AgNPs, greatly reducing the amount of AgNPs and their potential side effects. It has great practical value for attaching ATA to the high-efficiency particulate air network in the air purifier, which can kill the virus attached to it and limit its spread.

Enhanced optical and electrical properties of PEO/PMMA/TiO2 nanocomposites for optoelectronic applications

In this study, we synthesized titanium oxide (TiO2) nanoparticles (NPs) via the sol-gel process and incorporated them into a polymer blend of polyethylene oxide (PEO) and polymethyl methacrylate (PMMA) to form PEO/PMMA/TiO2 nanocomposites. The TiO2 NPs were integrated into the polymer matrix using the casting method at varying concentrations (1, 2, and 3 wt.%). The structural, morphological, optical, and electrical properties of the prepared TiO2 and nanocomposite films were thoroughly characterized using techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, and electrical impedance spectroscopy (EIS). TEM analysis revealed predominantly spherical TiO2 NPs with an average particle size of 15 nm. XRD and FTIR analyses confirmed the successful incorporation of TiO2 NPs and their interaction with the polymer chains, leading to modifications in the crystalline structure and chemical bonding of the nanocomposites. UV-Vis spectroscopy demonstrated a redshift in the absorption edge and increased absorbance with higher TiO₂ content, indicating enhanced optical properties. The indirect optical bandgap was observed to decrease from 4.19 eV to 2.21 eV as the TiO2 concentration increased, enhancing the material's photoresponsiveness. Additionally, the refractive index increased from 2.11 to 2.91, further supporting the potential for optical applications. EIS results showed a decrease in bulk resistance with increasing TiO2 concentration, suggesting improved electrical conductivity. These findings highlight the potential of PEO/PMMA/TiO2 nanocomposites for optoelectronic applications, where enhanced optical properties, such as improved light absorption, higher refractive index, and improved charge transport, are critical for device performance. The study offers an understanding of the PEO/PMMA/TiO2 nanocomposites, laying a foundation for future research in their applications in optoelectronic devices.

Isolation and characterization of biomass waste based bioplasticizer from Eucalyptus leaf: A suitability analysis of biofiller for polymeric composites

Plasticizers improve polymeric materials' properties and processability as additives. Currently, a variety of liquid synthetic plasticizers derived from fossil fuels are available. The environmental unsuitability of these materials could potentially lead to adverse effects on the environment. When we compare solid and liquid plasticizers, we find an infinite variety of liquid plasticizers. As a result, our work focuses on the extraction of plasticizer from plant sources. Accordingly, the plasticizer is extracted from eucalyptus leaves via solvent purification and surface catalysis. Research was conducted utilizing X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Ultraviolet (UV) visible spectroscopy to determine the characteristics of plasticizer. The scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analysis are used to analyze the surface morphology of the isolated plasticizer. The plasticizer's UV examination reveals active absorption at 375.21 nm. The plasticizer was determined to have a lower density of 0.941 g/cm3. The plasticizer that was extracted had a low solubility in water and organic solvents while possessing an estimated molecular weight of 340. The glass transition temperature of plasticizer was also examined using differential scanning electron microscopy analysis and found to be 64.17°C. The crystallinity index and size were found to be 34.08% and 28.57 nm, respectively. The characteristic features obtained were well-suited for use as filler in polymer composite materials.

Enhanced Specific Capacitance and Cycling Stability of Li2Cu2(MoO4)3 of NASICON Family of Supercapacitor Applications

AbstractNASICON electrode materials exhibit a broad spectrum of electrochemical potentials, robust ionic conductivity, and structural and thermal stabilities. Using solid state reaction method, Li2Cu2(MoO4)3 was synthesized, a member of NASICON family of compounds based on molybdenum. Various analytical techniques employed to assess structural and morphological properties of synthesized nanomaterial. X‐ray diffraction (XRD) pattern indicated that generated Li2Cu2(MoO4)3 nanomaterial exhibited orthorhombic crystalline structure, with crystallite size of approximately 48 nm. The nanomaterial morphology was evaluated using field emission scanning electron microscopy (FESEM), showing columnar‐ or fiber‐like morphology composed of some conductivity points. The elemental composition of Li2Cu2(MoO4)3 was analyzed by EDAX analysis, confirming the presence of elements lithium, copper, molybdenum, and oxygen. The optical properties and band gap of Li2Cu2(MoO4)3 were analyzed by ultraviolet visible diffuse reflectance spectroscopy (UVDRS). Elemental composition of surface along with electronic states and oxidation states of component present in the nanomaterial Li2Cu2(MoO4)3 were investigated from X‐ray photoelectron spectroscopy (XPS). Electrochemical evaluation using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopic (EIS) showed a specific capacitance of 250 F g−1 at 3.5 A g−1 with the high retention rate of 95.82% after 3000 cycles, indicating its potential for high performance supercapacitors.

Improvement in the performance of indium free dye sensitized solar cell by the use of polyaniline composite

The photovoltaic study of the fabricated dye sensitized solar cells is revealed in this paper. To provide indium free approach, fluorine doped tin oxide (FTO) and aluminium doped zinc oxide (AZO) glass substrate were used as charge collectors for counter electrodes and photoanode respectively. Also, a novel and natural mixed dye was used as sensitizer and mixture of doped polymer (polyaniline with metallic oxides of tin, vanadium and cerium) and iodide-triiodide couple was utilized as electrolyte for the cell. Optical band gap and light absorption performance of dyes were studied by ultraviolet-visible (UV-vis) spectroscopy. Surface morphology and elemental composition of polymer composites was studied using scanning electron microscopic (SEM) with energy dispersive X ray (EDX) analysis. Phase analysis of the composites was determined by X-ray diffraction and thermal behavior with the help of thermo gravimetric analysis (TGA). Photovoltaic characteristics (I-V) and induced photon to current efficiency (IPCE) measurements were also investigated. Highest IPCE of 17.7% was observed when polyaniline was doped with oxide of vanadium. Hence an efficient, green, indium free and novel cell is fabricated by the usage of different charge collector substrate, natural dye sensitizer and quasi solid-state electrolyte.

Biophysical insight into the interaction mechanism of 4-bromo-N-(thiazol-2- yl)benzenesulfonamide and human serum albumin using multi-spectroscopic and computational studies

4-Bromo-N-(thiazol-2-yl)benzenesulfonamide (1) is enriched with bioactive components and is highlighted for its pharmacological properties. However, its pharmacokinetic characteristics are yet to be reported. The interaction of compound 1 with carrier proteins in the bloodstream is an important factor that affects its potential therapeutic efficacy. This study aimed to elucidate the pharmacokinetic mechanisms of compound 1 in relation to human serum albumin (HSA) using multi-spectroscopic and computational techniques. Its predicted drug-like properties revealed no mutagenicity, although potential hepatotoxicity and interactions with certain cytochrome P450 enzymes were observed. Spectroscopic analyses extensively provided the interaction between HSA and 1 through a static fluorescence quenching mechanism with spontaneous hydrophobic interactions and hydrogen bonding. The binding constant of the HSA‒1 complex was relatively moderate to strong at a level of 106 M−1. Various spectroscopic techniques including ultraviolet-visible, Fourier-transform infrared, and circular dichroism spectroscopies indicated that its binding induced alteration in the α-helix content of HSA. Competitive binding and molecular docking studies designated the preferential binding of 1 to sub-structural domain IIA binding site I of HSA. Molecular dynamic simulations further illustrated the formation of a stable complex between 1 and HSA, accompanied by conformational changes in the protein. Importantly, esterase capacity of the HSA‒1 complex increased compared to the free HSA. Therefore, elucidation of the HSA‒1 binding mechanism provides valuable insights into the pharmacokinetics, suggesting potential benefits for the further development of 1 as a therapeutic agent.

Breaking New Grounds: solid-state synthesis of TiO2 – La2O3 – CuO Nanocomposites for degrading Brilliant Green dye under Visible Light

Environmental pollution, particularly from industrial dyes and chemicals, poses a significant threat to ecosystems and human health. Traditional pollution mitigation methods are often inefficient and costly. Photocatalysis has emerged as a promising solution for degrading pollutants using light energy. Titanium dioxide (TiO2) is a widely studied photocatalyst due to its stability, non-toxicity, and strong oxidative power. However, its efficiency is limited by a wide bandgap, restricting absorption to the UV region, and rapid electron-hole recombination. To address these limitations, doping TiO2 with materials like La2O3 and CuO has been explored to enhance its photocatalytic activity under visible light. This study investigates the enhancement of TiO2 nanocomposites by incorporating La2O3 and CuO. X-ray diffraction (XRD) revealed that the nanocomposites retained TiO2's anatase and rutile phases with improved crystallinity. Scanning electron microscopy (SEM) displayed spherical nanoparticles forming agglomerates, typically due to high surface energy. Energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) confirmed the presence of La and Cu in the TiO2 matrix. Fourier-transform infrared (FTIR) spectroscopy identified characteristic vibrational modes of Ti–O, La–O, and Cu–O bonds, suggesting strong chemical interactions between dopants and TiO2 lattice. Ultraviolet-visible (UV-Vis) spectroscopy showed a red shift in absorption spectra with La2O3 and CuO addition, reducing the bandgap energy from 3.23 eV (pure TiO2) to 2.27 eV for the TiO2–0.1La2O3–0.2CuO composite. Photoluminescence (PL) spectroscopy indicated improved charge separation and reduced electron-hole recombination rates in the synthesized nanocomposites. Photocatalytic performance was evaluated by degrading Brilliant Green (BG) dye under visible light. The TiO2–0.1La2O3–0.2CuO (TLC0.2) nanocomposite achieved a maximum dye degradation of over 95% after 204 minutes under optimal conditions (C0 = 17 mg/L and a S/L ratio of 1 g/L). Adding the inorganic agent Na2SO4 to this process significantly enhanced photocatalytic activity, increasing degradation from 56% to 95% after 180 min of visible light irradiation under C0 = 20 mg/L and S/L = 0.5 g/L conditions, as it shows a high stability after six reuse cycles. In conclusion, La2O3 and CuO doping significantly enhance TiO2 nanocomposites' crystalline structure, morphology, optical properties, and photocatalytic efficiency, demonstrating their potential for environmental remediation and solar energy conversion.

LITERATURE REVIEW ON HPLC METHODS FOR ESTIMATION OF EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE TABLETS

Emtricitabine and Tenofovir Disoproxil Fumarate (TDF) are essential components of antiretroviral therapy (ART) for HIV infection. Accurate quantification of these drugs in pharmaceutical formulations is crucial for ensuring therapeutic efficacy and patient safety. High-Performance Liquid Chromatography (HPLC) is a widely used analytical technique for this purpose. Several validated HPLC methods have been developed, employing diverse chromatographic conditions and detection techniques. These methods typically utilize reversed-phase C18 columns and UV detection at 260 nm or 270 nm. Key considerations for method development include selectivity, sensitivity, accuracy, precision, linearity, and robustness. Additionally, other analytical techniques such as Ultra-High Performance Liquid Chromatography (UHPLC), Thin-Layer Chromatography (TLC), Fourier Transform Infrared Spectroscopy (FTIR), and Ultraviolet-Visible (UV-Vis) Spectroscopy have been explored for the analysis of Emtricitabine and TDF. However, HPLC remains the preferred method due to its versatility, sensitivity, and reliability.