Research on Chemical Intermediates最新文献

Porphyrins emerge as promising catalysts due to their excellent activity. The incorporation of the transition metal (TM) atoms into the porphyrin cores can modulate their properties and catalytic characters. The structures, electronic, and magnetic properties of the transition metal (TM) loaded 5,10,15,20-(tetra-4-aminophenyl) porphyrins (TAPP-M) have been investigated using the density functional theory. The results indicate that most TM atoms are located at the center planes of the TAPP-M, with exceptions for the Y, Zr, and Nb atoms. The TAPP-Ti and TAPP-Zr demonstrate high binding energies per atom of − 5.528 eV and − 5.535 eV, indicating high structural stability. The TAPP-Cr and TAPP-Mo porphyrins exhibit narrower energy gaps, indicating potentially high reactivity as excellent electrocatalytic materials. The TAPP-Ti, TAPP-Co, TAPP-Zr, and TAPP-Ru display more adsorption energies than their neighbors. Higher charges were obtained for the TM atoms (TM = Sc, Zn, Y, and Cd) in TAPP-M, with the values of 1.378 |e|, 0.715 |e|, 1.674 |e|, and 0.833 |e|. Spin densities of the TM atoms in the TAPP-M porphyrins generally approach zero, while that of the TAPP-V is an exception at 2.484 |e|. It suggests that the spatial distributions of biological enzymes with TAPP-V as active centers can be regulated by external magnetic fields, allowing enzymes to exhibit higher catalytic efficiency.

This study investigates the photocatalytic performance of single and co-doped Ag/Ni-BaWO₄ for hydrogen (H₂) production, Methyl Violet (MV) dye degradation, and bacterial disinfection under visible light irradiation. BaWO₄ samples doped with silver (Ag) and nickel (Ni) were synthesized using the precipitation method and characterized using various techniques, including SEM, XRD, Raman, and XPS. The SEM images revealed spherical morphology, while XRD showed slight shifts in diffraction peaks due to doping. Photoluminescence (PL) spectra indicated that the co-doped samples had the highest luminescence intensity, attributed to charge separation enhancement, with band gap energies of 2.55 eV, 2.54 eV, and 2.56 eV for Ag-BaWO₄, Ni-BaWO₄, and Ag/Ni-BaWO₄, respectively. The co-doped Ag/Ni-BaWO₄ exhibited the highest photocatalytic activity, with a degradation efficiency of 98% for MV compared to 71% for Ni-BaWO₄ and 84% for Ag-BaWO₄. For hydrogen production, the optimal formic acid concentration was 750 ppm, and the catalyst dosage was 0.2 g, resulting in high hydrogen yields over 4 h. The Ag/Ni-BaWO₄ catalyst also displayed strong antibacterial activity, achieving 100% inactivation of Escherichia coli at 1000 µg/ml but showing no significant effect on Enterococcus faecalis. The study highlights Ag/Ni-BaWO₄ as a promising photocatalyst for environmental remediation and H₂ production, driven by visible light. The proposed mechanism involves charge separation, electron–hole pair generation, and radical formation, contributing to efficient photocatalytic reactions.

N-ZnO/g-C₃N₄ (MZC) composites with varying N-ZnO contents were fabricated by a green grinding strategy aimed at constructing an S-scheme heterojunction with enhanced visible-light catalytic performance. The characterizations and properties of these photocatalysts, along with the reaction mechanism, were investigated in detail. Especially, the transfer direction of photoexcited electrons in the MZC was commendably determined by X-ray photoelectron spectroscopy (XPS) analysis. The results demonstrated that the MZC presented superior performances in the reduction of CO₂ and the degradation of ciprofloxacin compared with single components. Therein, the MZC-20 achieved the best photocatalytic degradation efficiency of 99.7% within 50 min, with its rate constant being 29.08- and 10.09-fold compared with bare N-ZnO and g-C₃N₄, respectively. Additionally, the CO yield of the optimized MZC-20 was 1.451 μmol·g⁻¹·h⁻¹ in the absence of sacrificial agent and was 2.93 times that of pristine g-C₃N₄. The boosted catalytic performance of the MZC composite stemmed chiefly from the formed S-scheme heterojunction and the enhanced light harvesting, resulting in the effective separation and utilization of free carriers. The present work affords a way of resolving the limited performance for g-C₃N₄, as well as offers some insights into designing fresh S-scheme composites with widespread applications in renewable energy production and environmental cleaning.

The present work reports the synthesis of pure and Zr-doped hematite nanoparticles from the thermally induced polymorphic transformation from magnetite nanoparticles. The microstructural phases and parameters of the nanoparticles were investigated with X-ray diffraction. It is found that transformation from magnetite to hematite is delayed with increasing Zr content. The absence of X-ray diffraction peaks related to metallic Zr and its oxide in the doped samples indicates the dopant was uniformly distributed in the host hematite matrix. Fourier transform infrared spectroscopy and diffuse reflectance spectroscopy were carried out to investigate the optical properties of the nanoparticle samples. The decrease in IR absorbance intensity and shifting of the absorption bands to a lower frequency was observed with Zr doping in hematite, indicating a reduction in crystallinity and substitutional doping with the host element, respectively. It was found that the Zr doping improves the visible light absorption and decreases the band gap of hematite nanoparticles. X-ray photoelectron spectroscopy results confirmed the + 4 oxidation state of Zr dopant in the host lattice, and Zr-doped hematite nanoparticles indicated a decrease in octahedral coordination with an increase in tetrahedral coordination of Fe³⁺ oxidation state. Room-temperature magnetic properties were investigated with the vibrating sample magnetometer. A significant improvement in photocatalytic properties of hematite was found with Zr doping.

Infectious diseases, induced by various pathogenic microorganisms, can enter the body and disrupt normal physiological functions, leading to a range of symptoms and health complications. So, to ascertain a significant anti-infectious agent against antimalarial and anti-tuberculosis ailments, the previously synthesized and extensively characterized (mass spectrometry, NMR (¹H and ¹³C), electronic spectra, infrared, magnetic moment, ESR, molar conductance, powder XRD, SEM and EDAX) Schiff base ligands (1–4) and their octahedral Co(II), Ni(II), Cu(II), Zn(II) complexes (5–20) were studied. The biological evaluation demonstrated that compounds (1, 5–8) and (3, 13–16) showed high potency against malaria and tuberculosis, respectively. Furthermore, Zn(II) complexes (8) and (16) exhibited the greatest efficacy, with IC₅₀ value of 0.32 ± 0.06 µM and MIC value of 0.0081 µmol/mL. Moreover, molecular docking investigation against the 1U5A, 8E1Z proteins for malaria and 5V3Y, 3PTY proteins for TB, along with ADMET investigations, was conducted on highly active compounds (1, 3, 5–8, 13–16) to validate their biological findings. The theoretical analysis also supported the superior efficacy of (8) and (16) complexes, demonstrating their lowest binding affinity (1U5A (− 8.1 kcal/mol), 8E1Z (− 8.9 kcal/mol), 5V3Y (− 10.1 kcal/mol), 3PTY (− 10.2 kcal/mol)), favorable coordination modes and drug likeness property.

Twelve homoleptic Cu(I) complexes with triazine-type ligands were designed and analyzed theoretically for their possible application in dye-sensitized solar cells (DSSC). This research analyzed the effect of π-conjugation and substitution of different anchoring groups in the triazine ligands. The molecular structures of the compounds were obtained through density functional theory (DFT). A relationship between complex geometry distortion (τ₄) and optoelectronic properties was found. UV–Vis absorption spectra and electronic transitions were studied using time dependent-density functional theory (TD-DFT). The complexes presented absorption bands in the 300–655 nm range, attributed to metal → ligand and ligand-to-ligand transfer. Energy levels of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) meet the requirements to consider molecular proposals as sensitizers. Chemical reactivity parameters of interest were obtained and analyzed, such as chemical hardness (η), electron-donating power (ω⁻), electron-accepting power (ω⁺), and electrophilicity index (ω). For all Cu(I) complexes, a relation was found between chemical hardness and τ₄ values. The free energy electron injection (ΔG_Inject) and light harvesting efficiency (LHE) were determined and discussed. All previous studies indicate that all complexes present interesting properties like dyes in DSSC applications.

The utilization of visible light irradiation in organic synthesis has garnered significant attention due to its environmentally friendly nature and efficiency. In this study, we explore the application of graphitic carbon nitride (g-C₃N₄) as a photocatalyst for the synthesis of 2-Arylbenzothiazole under visible light irradiation. The reaction conditions were optimized to achieve high yields (89–97%) and selectivity of products. Characterization techniques such as FTIR spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and UV–Vis Diffuse Reflectance Spectra (DRS) were employed to analyze the catalyst structure. The results demonstrated that g-C₃N₄ acted as an effective photocatalyst, facilitating the synthesis of benzothiazole with excellent yields (89–97%). This approach marks a notable improvement over prior methodologies, leading to significantly faster reaction times and improved yields. Additionally, the exceptional recyclability of g-C₃N₄ allows it to be reused in multiple reaction cycles without significant loss of activity, which is a crucial factor in reducing waste and resource consumption, facilitating a greener process. Consequently, it highlights g-C₃N₄’s potential for sustainable and eco-friendly synthesis of 2-Arylbenzothiazole and other valuable organic compounds.

Graphical abstract

• The g-C₃N₄ was synthesized by thermal polymerization of urea, and was characterized through several technique such as XRD, FTIR, SEM, and DRS.

• g-C₃N₄ was used as highly efficient photocatalyst of 2-arylbenzothiazole under visible light irradiation.

• Benzothiazoles were successfully prepared, yielding 89–97% in a brief stirring time of 5–15 min.

• g-C₃N₄ continued to exhibit high catalytic activity after being recycled multiple times, without any significant degradation.

The current research work highlighted the bio-fabrication of tin oxide nanoparticles (SnO₂ NPs) by employing Phyllanthus emblica leaf extract. These investigations concentrated on the physiochemical characteristics of the developed material and examined their effectiveness as photocatalysts and antibacterial agents. The structural characteristics of the bio-fabricated SnO₂NPs were investigated by XRD, SEM, FTIR, and UV spectroscopic techniques. Photocatalytic efficacy of the constructed materials was evaluated in the removal of the 2,4 dicholorophenoxy acetic acid (2,4 D); meanwhile, the antibacterial potency of the developed material was assessed against the chosen bacterial strain Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes. The XRD and SEM examination revealed that the particles are spherical with diameters ranging from 50 to 60 nm. Subsequently, the developed SnO₂ NPs demonstrated significant photocatalytic potency in the removal of the 2,4 D from the aqueous solution, and approximately 74% of organic pollutants were removed from the aqueous solution within the period of 120 min. The antibacterial assay demonstrated that the developed material shows significant inhibition of the tested bacterial strain. Maximum inhibition was observed against the Klebsiella pneumoniae with the 21 mm zone of inhibition at 60 µg/mL.