Amplification of photocatalytic degradation of antibiotics (amoxicillin, ciprofloxacin) by sodium doping in nano-crystallite hydroxyapatite.

In this research, we explain the production of sodium-doped hydroxyapatite (Na_HAp) via wet chemical precipitation, followed by crystal modification. To enhance its photocatalytic activity different % of (0.25, 0.5, 1, and 2) sodium doped into HAp crystal. It has been demonstrated that doping is an effective method for modifying the properties of nanomaterials, such as their optical performance and chemical reactivity. Several instrumental approaches were used to characterize this newly synthesized sodium-doped HAp (Na_HAp), e.g. scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UV-vis spectrometry were used to analyze the morphology, elemental composition, crystal structure, and optical bandgap, respectively. Under sunlight irradiation, the new Na_HAp photocatalyst was put to use in the process of degrading pharmaceutical pollutants such as antibiotics (amoxicillin and ciprofloxacin). It was found that using a 0.1 g dose of 1% Na_HAp under specified conditions, such as a pH of 7 and 120 minutes of sunlight irradiation, resulted in degradation percentages of 60% and 41.59% for amoxicillin and ciprofloxacin, respectively. Different radical scavengers were utilized to determine the reaction mechanism for the photochemical degradation of antibiotics. Additionally, the ability to be reused and the stability of 1% Na_HAp, a newly developed photocatalyst, were assessed. Therefore, this research adds to our understanding of how to optimize redox capacity for the rapid breakdown of a variety of antibiotics when exposed to sunlight.

Extraction and characterization of a novel cellulosic fiber derived from the bark of Rosa hybrida plant.

The current investigation aims to choose an alternate potential replacement for the nonbiodegradable synthetic fibers used in polymer composites. This goal motivated the thorough characterization of Rosa hybrida bark (RHB) fibers. The research explored fiber characterization such as morphological, mechanical, thermal, and physical properties. The suggested fiber features a percentage of cellulose, hemicellulose molecules, and lignin of 52.99 wt%, 18.49 wt%, and 17.34 wt%, respectively according to chemical composition studies, which improves its mechanical properties. It is suitable for lightweight applications due to its decreased density (1.194 gcm-3). The purpose of the Fourier transform infrared spectroscope was to observe and record how various chemical groups were distributed throughout the surface of the fiber. The presence of 1.41 nm-sized crystalline cellulose and further XRD analysis showed a crystallinity index of 75.48 %. Scanning electron microscope studies revealed that RHB fibers have a rough surface. According to a single fiber tensile test, for gauge length (GL) 40 mm, Young's modulus and tensile strength of RHB fibers were 6.57 GPa and 352.01 MPa, respectively, and for GL 50 mm, 9.02 GPa and 311 MPa, respectively. Furthermore, thermo-gravimetric examination revealed that the isolated fibers were thermally stable up to 290 °C and the kinetic activation energy was found to be 75.32 kJ/mol. The fibers taken from the Rosa hybrida flower plants' bark exhibit qualities similar to those of currently used natural fibers, making them a highly promising replacement for synthetic fibers in polymer matrix composites.

A combined first principles and experimental approach to Bi2WO6.

Here we synthesized Bi2WO6 (BWO) using both solid-state reaction (SBWO) and hydrothermal (HBWO-U and HBWO-S) methods. The orthorhombic Pca21 phase purity in all samples is confirmed from Rietveld refinement of X-ray diffraction data, Raman spectroscopy, and Fourier transform infrared spectroscopy. The HBWO-U and HBWO-S morphology revealed rectangular, spherical, and rod-like features with an average particle size of 55 nm in field emission scanning electron micrographs. A high-resolution transmission electron micrograph showed spherical-shaped particles in the HBWO-U sample with an average diameter of ∼10 nm. The diffuse reflectance-derived indirect electronic band gaps lie within the 2.79-3.23 eV range. The BWO electronic structure is successfully modeled by Hubbard interaction Ud and Up corrected Perdew-Burke-Ernzerhof generalized gradient approximation GGA-PBE+Ud+Up with van der Waals (vdW) force in effect. The optimized (Ud, Up) values are further justified by tuning the Hartree-Fock (HF) exact-exchange mixing parameter αHF from 25% in Heyd-Scuseria-Ernzerhof (HSE06) to 20% in the PBE-HF20% functional. Moreover, no inconsistencies were seen in the GGA-PBE+Ud+Up+vdW simulated crystallographic parameters, and the elastic tensor, phonon, and linear optical properties. Overall, the computationally cheap GGA-PBE+Ud+Up with vdW force may have successfully probed the physical properties of BWO.

Influence of Zn-substitution on structural, magnetic, dielectric, and electric properties of Li-Ni-Cu ferrites.

The polycrystalline Li0.15Ni0.6-xZnxCu0.1Fe2.15O4 ferrites are fabricated by the method of conventional solid-state reaction technique. The X-ray diffraction (XRD) confirms that the structure of the composition is a single-phase cubic spinel structure for all samples. The particle size of the compositions is varied from 36 to 52 nm. The lattice parameter and densities are found to increase with enhancing Zn content, as the ionic radius and atomic weight of Zn are greater than Ni. The porosity exhibits a decreasing trend. The average grain size determined using Field Emission Scanning Microscopy (FESEM) increases until x = 0.40, then declines. The Energy-Dispersive Spectroscopy (EDS) examination revealed that the percentage of obtained elements is well matched with the stoichiometric elements. The addition of Zn content acts as an accelerator for enhancing the value of the real part of initial permeability and the highest value is obtained (µi' = 276) for the x = 0.40 sample, as well as the highest relative quality factor (RQF) of around 3000. The loss factor for the Zn substituted composition is nine times lower than for the parent composition. The optimum saturation magnetization of around 77.49 emu/g is found for the x = 0.40 sample. The maximum dielectric constant (ε' = 2.85 × 103) is found for x = 0.10 samples at 10 kHz. Further, from impedance studies, the non-Debye type dielectric relaxation is seen for the Zn-substituted samples. The observed region of the imaginary electric modulus peak signifies the transition of charge carrier mobility from a larger range to a short-range distance. The phenomenon of ac conductivity is attributed to the process of the small polaron hopping mechanism.

Comprehensive review of micro/nanostructured ZnSnO3: characteristics, synthesis, and diverse applications.

Generally, zinc stannate (ZnSnO3) is a fascinating ternary oxide compound, which has attracted significant attention in the field of materials science due to its unique properties such high sensitivity, large specific area, non-toxic nature, and good compatibility. Furthermore, in terms of both its structure and properties, it is the most appealing category of nanoparticles. The chemical stability of ZnSnO3 under normal conditions contributes to its applicability in various fields. To date, its potential as a luminescent and photovoltaic material and application in supercapacitors, batteries, solar cells, biosensors, gas sensors, and catalysts have been extensively studied. Additionally, the efficient energy storage capacity of ZnSnO3 makes it a promising candidate for the development of energy storage systems. This review focuses on the notable progress in the structural features of ZnSnO3 nanocomposites, including the synthetic processes employed for the fabrication of various ZnSnO3 nanocomposites, their intrinsic characteristics, and their present-day uses. Specifically, we highlight the recent progress in ZnSnO3-based nanomaterials, composites, and doped materials for their utilization in Li-ion batteries, photocatalysis, gas sensors, and energy storage and conversion devices. The further exploration and understanding of the properties of ZnSnO3 will undoubtedly lead to its broader implementation and contribute to the advancement of next-generation materials and devices.

ß-tricalcium phosphate synthesized in organic medium for controlled release drug delivery application in bio-scaffolds.

ß-tricalcium phosphate (ß-TCP) was synthesized in an organic medium (acetone) to obtain a single-phase product while calcium carbonate (CaCO3) and ortho-phosphoric acid (H3PO4) were the sources of Ca, and P, respectively. The synthesized ß-TCP was characterized by employing a number of sophisticated techniques vis. XRD, FTIR, FESEM, VSM and UV-Vis-NIR spectrometry. On the other hand, cytotoxicity, hemolysis, and antimicrobial activity for Gram-negative as well as Gram-positive (E. coli and S. aureus) bacteria were explored using this synthesized sample in powder format. However, to assess the drug loading and releasing profile, these powdered samples were first compressed into disks followed by sintering at 900 °C. Prior to loading the drug, porosity, density, and water absorbance characteristics of the scaffolds were examined in deionized water. Both loading and releasing profiles of the antibiotic (ciprofloxacin) were looked over at various selected time intervals which were continued up to 28 days. The observed results revealed that 2.87% of ciprofloxacin was loaded while 37% of this loaded drug was released within the selected time frame as set in this study. The scaffold was also immersed in SBF solution maintaining identical interim periods for the bioactivity evaluation. Furthermore, all three types of samples (e.g. drug-loaded, drug-released, and SBF-soaked) were characterized by FESEM and EDX while antimicrobial activity (against E. coli, S. typhi, and S. aureus) and efficacy to prevent hemolysis were also investigated. The drug-loaded scaffold presented a larger inhibition zone than the standard for all three types of microbes. Although powdered ß-TCP was inactive in killing the Gram-negative bacteria, surprisingly the drug-released scaffold showed an inhibition zone.

Influence of Sn doping on the optoelectronic properties of ZnO nanoparticles.

Zinc Oxide (ZnO) nanoparticles (NPs) obtained a lot of attention from researchers and industries because of their superior properties as an optoelectronic material. Doping, especially tin (Sn), can further fine-tune their optoelectronic properties. In this manuscript, we have reported the optoelectronic properties of Sn-doped ZnO NPs, which were synthesized by a simple chemical solution method. A wide range of dopant (Sn) concentrations were used in the ratios of 0, 1, 3, 5, 7, and 10 weight percent. The effects of dopant (Sn) concentration on the structural, morphological, elemental composition, and optical properties of ZnO NPs were investigated by using an X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM), X-ray photoelectron spectrometer (XPS) and UV-Vis-NIR respectively. XRD analysis revealed the shifting of diffraction patterns towards a higher angle along with decreasing intensity. The calculated crystallite size using the XRD varied from 40.12 nm to 28.15 nm with an increasing doping percentage. Sn doping notably influences the size of ZnO NPs, along with crystal quality, strain, and dislocation density. The X-ray photoelectron spectroscopy (XPS) study showed the presence of zinc (Zn), oxygen (O), and tin (Sn) with their preferred oxidation states in the synthesized NPs. UV-Visible spectroscopy (UV-Vis) showed that the bandgap changed from 3.55 to 3.85 eV with the increasing concentration of Sn. FE-SEM revealed that the structures and surfaces were irregular and not homogeneous. The above findings for ZnO nanostructures show their potential application in optoelectronic devices.

An ab initio DFT perspective on experimentally synthesized CuBi2O4.

Here we present a comprehensive density functional theory (DFT) based ab initio study of copper bismuth oxide CuBi2O4 (CBO) in combination with experimental observations. The CBO samples were prepared following both solid-state reaction (SCBO) and hydrothermal (HCBO) methods. The P4/ncc phase purity of the as-synthesized samples was corroborated by Rietveld refinement of the powdered X-ray diffraction measurements along with Generalized Gradient Approximation of Perdew-Burke-Ernzerhof (GGA-PBE) and the Hubbard interaction U corrected GGA-PBE+U relaxed crystallographic parameters. Scanning and field emission scanning electron micrographs confirmed the particle size of the SCBO and HCBO samples to be ∼250 and ∼60 nm respectively. The GGA-PBE and GGA-PBE+U derived Raman peaks are in better agreement with that of the experimentally observed ones when compared to local density approximation based results. The DFT derived phonon density of states conforms with the absorption bands in Fourier transform infrared spectra. Both structural and dynamic stability criteria of the CBO are confirmed by elastic tensor and density functional perturbation theory-based phonon band structure simulations respectively. The CBO band gap underestimation of GGA-PBE as compared to UV-vis diffuse reflectance derived 1.8 eV was eliminated by tuning the U and the Hartree-Fock exact-exchange mixing parameter αHF in GGA-PBE+U and Heyd-Scuseria-Ernzerhof (HSE06) hybrid functionals respectively. The HSE06 with αHF = 14% yields the optimum linear optical properties of CBO in terms of the dielectric function, absorption, and their derivatives as compared to that of GGA-PBE and GGA-PBE+U functionals. Our as-synthesized HCBO shows ∼70% photocatalytic efficiency in degrading methylene blue dye under 3 h optical illumination. This DFT-guided experimental approach to CBO may help to gain a better understanding of its functional properties.

Combined experimental and DFT approach to BiNbO4 polymorphs.

Here we present a detailed ab initio study of two experimentally synthesized bismuth niobate BiNbO4 (BNO) polymorphs within the framework of density functional theory (DFT). We synthesized orthorhombic α-BNO and triclinic ß-BNO using a solid-state reaction technique. The underlying Pnna and P1̄ crystal symmetries along with their respective phase purity have been confirmed from Rietveld refinement of the powdered X-ray diffraction measurements in combination with generalized gradient approximation of Perdew-Burke-Ernzerhof (GGA-PBE) based DFT simulations. The scanning electron micrographs revealed average grain sizes to be 500 nm and 1 µm for α-BNO and ß-BNO respectively. The energy-dispersive X-ray spectroscopy identified the Bi, Nb, and O with proper stoichiometry. The phase purity of the as-synthesized samples was further confirmed by comparing the local density approximation (LDA) norm-conserving pseudo-potential based DFT-simulated Raman peaks with that of experimentally measured ones. The relevant bond vibrations detected in Fourier transform infrared spectroscopy were matched with GGA-PBE derived phonon density of states simulation for both polymorphs. The structural stability and the charge dynamics of the polymorphs were verified from elastic stress and born charge tensor simulations respectively. The dynamical stability of the α-BNO was confirmed from phonon band structure simulation using density functional perturbation theory with Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional. The electronic band gaps of 3.08 and 3.36 eV for α-BNO and ß-BNO measured from UV-Vis diffuse reflectance measurements were matched with the sophisticated HSE06 band structure simulation by adjusting the Hartree-Fock exchange parameter. Both GGA-PBE and HSE06 functional were used to simulate complex dielectric function and its derivatives with the help of Fermi's golden rule to define the optical properties in the linear regime. All these may have provided a rigorous theoretical analysis for the experimentally synthesized α-BNO and ß-BNO polymorphs.

Green synthesis of zinc oxide nanoparticles using Cocos nucifera leaf extract: characterization, antimicrobial, antioxidant and photocatalytic activity.

Zinc oxide nanoparticles (ZnO NPs) have been successfully prepared using Cocos nucifera leaf extract and their antimicrobial, antioxidant and photocatalytic activity investigated. The structural, compositional and morphological properties of the NPs were recorded and studied systematically to confirm the synthesis. The aqueous suspension of NPs showed an ultraviolet-visible (UV-Vis) absorption maxima of 370 nm, indicating primarily its formation. X-ray diffraction analysis identified the NPs with a hexagonal wurtzite structure and an average particle size of 16.6 nm. Fourier transform infrared analysis identified some biomolecules and functional groups in the leaf extract as responsible for the encapsulation and stabilization of ZnO NPs. Energy-dispersive X-ray analysis showed the desired elemental compositions in the material. A flower-shaped morphology of ZnO NPs was observed by scanning electron microscopy, with a grain size of around 15 nm. The optical properties of the NPs were studied by UV-Vis spectroscopy, and the band gap was calculated as 3.37 eV. The prepared ZnO NPs have demonstrated antimicrobial activity against T. harzianum and S. aureus, with a zone of inhibition of 14 and 10 mm, respectively. The photocatalytic behaviour of ZnO NPs showed absorbance degradation at around 640 nm and it discoloured methylene blue dye after 1 h, with a degradation maximum of 84.29%. Thus, the prepared ZnO NPs could potentially be used in antibiotic development and pharmaceutical industries, and as photocatalysts.

Facile extraction and characterization of calcium hydroxide from paper mill waste sludge of Bangladesh.

Herein, paper mill waste sludge (PMS) from two different sources has been investigated to extract calcium hydroxide, Ca(OH)2 by a facile and inexpensive extraction process. PMS samples, collected from local paper mill plants of Bangladesh, were the main precursors wherein HCl and NaOH were used for chemical treatment. The as-synthesized products were analysed by a variety of characterization tools including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) elemental analyses. Our studies confirm that the extracted product contains Ca(OH)2 as a major content, albeit it also includes CaCO3 phase owing to the inescapable carbonation process from the surrounding environment. The particle size of the synthesized products is in the range of 450-500 nm estimated from SEM micrographs. The crystallite domain size of the same estimated from XRD analyses and was found to be approximately 47 and 31 nm respectively for product-A and product-B considering major (101) Bragg peak of Ca(OH)2. The yield percentage of the isolated products is about 65% for samples collected from both sources.