Journal of Saudi Chemical Society最新文献

Local bacterial infection remains an increasingly severe threat to human health worldwide, and infection control is still a challenging task. Carbon Quantum Dots (CQSs) and barium tungstate show antibacterial properties. CQDs doped Barium Tungstate (BaWO₄) are synthesized by using a hydrothermal route and their optical and antimicrobial activities against the Gram-positive bacteria staphylococcus aureus and optical properties were investigated. The UV–Vis reveals a shift in the bandgap from 3.62 eV to 2.93 eV due to doping of CQDs in BaWO₄. The structure of the CQDs/BaWO₄ were studied by XRD, which shows CQDs doped BaWO₄ samples possess tetragona4 werelite structure with the preferred orientation of (1 1 2) identified by XRD at 26° having crystallite size ∼ 31 nm. Nanocomposite BaWO₄/CQDs exhibit a spherical-like shape and are composed of Ba, O, W and C according to the design of the experiment. Zeta sizer of CQDs by DLS shows the size of CQDs is 7.65 nm. The FT-IR shows the presence of functional groups in doped material like CC, CO, and COOH bonds which indicate that the C-dots are functionalized with epoxy, carbonyl, hydroxyl, and carboxylic acid groups. Their elemental composition and surface morphology were studied by EDS which shows the percentage variation of CQDs in BaWO₄, SEM results show the change in shape of the sample by adding CQDs to BaWO₄. The TEM image proves the presence of doped material in the BaWO₄. The PL spectra reveals the emission spectra shift towards a higher wavelength and absorption increases. The qualitative analysis shows the antimicrobial activity and enlargement of the inhibition zone and quantitative analysis confirms it.

Photocatalytic responses and synergistic effects of V₂O₅, TiO₂, and V₂O₅/TiO₂ heterostructures with varied ratios have been investigated, revealing promising outcomes. The successful synthesis of nanostructures and heterostructures was verified through energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses. Notably, ultraviolet–visible spectroscopy and photoluminescence spectral studies confirmed that the optical band gap of V₂O₅/TiO₂ heterostructures increases with higher TiO₂ concentrations. These findings enhance our understanding of the agglomerated heterostructures of V₂O₅/TiO₂, particularly with ratios of 1:1 and 1:3, showcasing potential applications in photocatalysis. Furthermore, their performance was subjected to Malachite Green dye degradation using a solar simulator, achieving an impressive efficiency of 93.29%. Additionally, the photocatalytic efficacy was assessed through reusability experiments over three cycles. Remarkably, the heterostructures exhibited stability across these cycles, suggesting their potential for extended use in diverse photocatalytic purposes. The importance of these results is the applicability of our fabricated V₂O₅/TiO₂ heterostructures as a photocatalyst with high performance, especially in the realm of sustainable and efficient dye degradation processes.

In this study, magnetic graphene oxide (MGO-Fe₃O₄) nanocomposite was prepared by co-precipitating of FeCl₃.6H₂O and FeCl₂.4H₂O on waste battery-derived graphene oxide and used as an adsorbent for the efficient removal of As(III) from aqueous solutions. The prepared nanocomposite was characterized by Fourier transformed infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, zeta potential, and a vibrating sample magnetometer. These characterizations revealed that spare like Fe₃O₄ nanoparticles (10.5 nm) were decorated on graphene oxide nanosheets and showed excellent saturation magnetization (89.73 emu/g). The adsorption of As(III) by MGO-Fe₃O₄ was optimized by analyzing various parameters. Experiments showed that 98 % of As(III) was removed at neutral pH in a just 20 min, even though the adsorbent dose was only 0.14 g/L. The adsorption kinetic and isotherm were best fitted with the pseudo-second order kinetic and Frendlich isotherm model. The maximum adsorption capacity (q_max) was found to be 50.2 mg/g at room temperature. Thermodynamic studies showed that the As(III) adsorption process was spontaneous and exothermic in nature. The enhanced adsorption capacity and magnetic properties of MGO-Fe₃O₄ are crucial in the drinking water treatment process due to the easy magnetic separation of MGO-Fe₃O₄ from aqueous solution after the adsorption process. Density Functional Theory (DFT) was also used to investigate the interaction between MGO-Fe₃O₄ and As(III), which further suggested that MGO-Fe₃O₄ and As(III) mostly interact with each other through surface complexation and hydrogen bonding.

The emergence of COVID-19 had an unprecedented impact on society, leading to the widespread usage and disposal of surgical face masks (FMs). This work contributes to repurposing FMs into carbon materials through simplified solvothermal-assisted pyrolysis processes for supercapacitor applications. XRD and FESEM were employed to investigate the materials' microstructural and micrographic characteristics. The FM 700 has a specific capacitance value of 182.61 Fg⁻¹, more significant than the other produced sample in the 1 M KOH electrolyte. The symmetric solid-state supercapacitor with a maximum capacitance of 92.67 Fg⁻¹ is constructed under perfect circumstances. After 10,000 cycles, FM 700-SSSD maintained 89 % of its value. Turning FMs into carbon materials for energy storage applications is made more accessible by this method and also prevents the environment from pollution.

This study utilized incipient wetness impregnation to synthesize bentonite materials and to enhance their physical characteristics with ruthenium (Ru) and strontium (Sr) ions. The atomic composition of the materials was confirm confirmed via the analysis of the EDX measurements. X-ray crystallography indicates that the materials have almost similar diffraction peak profiles, and that the addition of Sr increases the crystallinity of the bentonite grains. Dielectric and electrical properties, measured between 25 °C and 55 °C at frequencies of 1 kHz −1 MHz, revealed that the real and imaginary impedances increased upon the introduction of 5 % Ru and 5 % Sr, possibly due to Ru and Sr segregation into the grain boundaries, increasing the resistance of the bentonite granular structure. For all materials, the observed saturation of the real electric modulus at high frequencies, and the reduction of the permittivity with increasing frequency, may be explained by the Maxwell-Wagner interfacial polarization and Koop's empirical theory. This trend is more pronounced for the bentonite with Sr, highlighting the essence of the present work for engineering interfacial polarisation applications associated with supercapacitors and batteries.

N-Arylpyrazoles are important building blocks in many biologically active compounds, natural products, pharmaceuticals, and industries. It is an important moiety of various drugs and exhibits extensive biological activities viz., antibiotic, anticancer, antifungal, anti-inflammatory, anti-coagulant, analgesic, antipyretic, anti-depressant, insecticidal, and hyperglycemic activities. Various protocols have been designed for the synthesis of N-arylpyrazoles facilitated by a wide variety of metal-based catalysts at high or room temperature, metal free reactions, various named reactions, multicomponent reactions, and those occurring under different electromagnetic radiations. Various ligands are found to promote Cu-catalyzed N-arylation of pyrazole under mild conditions in short time. This review describes the synthesis and biological applications of N-arylpyrazole derivatives reported during 2019–2023.

This study introduces MnFe₂O₄@SiO₂-SiO₃H as a novel magnetic catalyst and thoroughly investigates its structure, catalytic activity, and reusability. The synthesis of the magnetic catalyst was meticulously characterized using an array of analytical techniques. Utilizing MnFe₂O₄@SiO₂-SiO₃H, the synthesis of functionalized oxazolidine-2-ones were performed, versatile compounds widely employed in chiral auxiliaries, protecting groups, and medicinal chemistry. Remarkably, the two-step process from chalcones demonstrated one of the shortest reported pathways, highlighting the efficiency of our novel nanocatalyst. To elucidate the stability and reactivity of the synthesized products, we employed Density Functional Theory (DFT) calculations, including molecular electrostatic potential (MEP) mapping and reactivity indices such as electronegativity, electrophilic index, softness, and hardness, as well as frontier molecular orbitals (HOMO-LUMO). Furthermore, our investigations extended to the recycling capabilities of the nanocatalyst. Through a comprehensive evaluation of at least five reaction cycles, MnFe₂O₄@SiO₂-SiO₃H showcased a remarkable retention of activity (97–92 %), reaffirming its reusability and long-term potential. Our research presents MnFe₂O₄@SiO₂-SiO₃H as a highly effective and recoverable nanomagnetic catalyst for organic reactions, with demonstrated applications in synthesizing functionalized oxazolidine-2-ones. As such, our findings offer a promising alternative to traditional methods, presenting new opportunities in catalysis and materials science.

The designed and synthesized multifunctional properties of bis-hydrazono[1,3,4]thiadiazoles became important for developing an efficient medication for Alzheimer’s disease. Thiadiazoles were characterized and studied towards this target as an acetylcholinesterase inhibitor (ChEIs). In this study, one-pot synthetic strategy was applied for the synthesis of bis-hydrazono[1,3,4]thiadiazole series from 2,2′-(1,2-diphenylethane-1,2-diylidene)bis(hydrazine-1-carbodithioic acid) and hydrazonoyl chlorides. The greener pastures, in silico, an environmentally-friendly and free computer-aided method, bioactivity studies of the bis-hydrazono[1,3,4]thiadiazoles 4a-h exhibited various possible interesting inhibitory activities against AChE showing similar behaviour to the approved drugs, Donepezil, Galantamine and Rivastigmine. For a fair comparison, the superpositions of 4a-h, and Donepezil, Galantamine and Rivastigmine docked together into the functional domain (binding pocket) of 1EVE to reveal interesting different molecular laydowns of the compounds. On the other side, the display of the molecules before and after docking was discussed. The binding affinity slightly differs between Donepezil, Galantamine, Rivastigmine, and the ligands 4a-h. The range of the recorded binding affinity for 4a-h is from (−9.4 to −8.4 kcal/mol⁻¹)^, whereas the binding affinity for Donepezil, Galantamine and Rivastigmine is (−11.1, −9.8 and −8.0 kcal/mol⁻¹ respectively), which is higher than all the prepared ligands.

Furthermore, the binding amino acids also varied among the studied compounds in this study. Phe290, Phe330, Phe331, Trp279, Tyr70, Tyr121 and Tyr334 are the common amino acids binding with the FDA-approved AChE inhibitors for treating AD, Donepezil, Galantamine and Rivastigmine and ligands. Notably, the number of hydrophobic and hydrogen interactions studied between the ligands 4a-h and the Donepezil, Galantamine and Rivastigmine drugs were compared as a preliminary indicator towards a successful inhibitor. The comparative study in this research work aims to rank our compounds with respect to the approved medications. This is a friendly environmental preliminary helpful indication before leaping into time and energy-consuming experimental work. Organ toxicological endpoints and toxicity-predicted activity were obtained using the ProTox-II web server for both the approved medication and ligands. Later, in-vitro acetylcholinesterase inhibition assays were conducted to assess the efficacy of bis-hydrazono[1,3,4]thiadiazoles 4a-h as inhibitors of acetylcholinesterase (AChE) in comparison to Donepezil. Results indicated promising inhibition activities for example 4 h, 4 g and 4d to the testing drug Donepezil for breaking down the neurotransmitter acetylcholine.

The primary objective of this research endeavor is to develop a highly sensitive and selective electrochemical sensor for the accurate detection of hydroquinone (HQ), a prevalent environmental contaminant. To achieve this, we employed a novel nanocomposite consisting of Ga₂O₃-doped ZnO (Ga₂O₃.ZnO) as the active nanomaterial for fabricating a glassy carbon electrode (GCE). The structure and morphology of the Ga₂O₃.ZnO nanocomposite were rigorously analyzed using a diverse range of techniques to ensure its suitability as the sensing nanomaterial. This innovative sensor exhibits remarkable capabilities, enabling the detection of HQ across a broad concentration range, spanning from 1 to 11070 µM, in a neutral phosphate buffer solution. It boasts an exceptionally high sensitivity of 1.0229 µA µM⁻¹ cm⁻² and an impressive detection limit of 0.063 µM. Thanks to its exceptional sensitivity and specificity, this sensor can precisely quantify HQ levels in real-world samples. Moreover, its outstanding reproducibility, repeatability, and stability establish it as a dependable and resilient choice for HQ determination.

The release rate and time are very important for the drug carriers, silica aerogel filled hydroxypropyl cellulose/chitosan (SA/HPC/CS) composites were fabricated for the release of 5-fluorouracil (5-Fu), and the release rate and time were regulated with the content of SA, pH value and external coating material. Firstly, the 5-Fu loaded SA/HPC/CS composites and Eudragit L100 coated composites were prepared with cross-linking followed by freeze-drying, and characterized by SEM, FTIR, XRD, DSC, and TG. Then, the effect of SA content on the encapsulation efficiency of SA/HPC/CS@5-Fu was investigated, and 5-Fu release behavior under different pH values from these aerogel composites was evaluated with four kinetic models. In addition, to further solve the abrupt effect of the obtained composites, Eudragit L100 coated SA/HPC/CS@5-Fu was fabricated, the sustained release behavior revealed that the coating technique can effectively improve the release behavior and extend release time.