Journal of Saudi Chemical Society最新文献

The development of novel and environmentally friendly solvents for chemical reactions is a vital in the pursuit of sustainable chemistry. This study presents a sustainable and efficient protocol for the rapid oxidation of benzaldehyde derivatives in the presence of catalytic Deep Eutectic Solvent (DES) system to their corresponding benzoic acids. A novel ternary DES composed of Urea/ZnCl₂/HCl was synthesized using a combination of Urea, ZnCl₂, and HCl for the first time and employed as an environmentally friendly oxidation catalyst using H₂O₂ as an oxidant at 60 °C. Benzaldehyde derivatives with diverse range of functional groups and substitution patterns afforded remarkable results, as it achieved high to excellent yields of the corresponding benzoic acids within a remarkably short reaction time of only 50 min. This protocol offers several advantages over alternative methods, including high product yields, the elimination of toxic and hazardous solvents and catalysts, and straightforward experimental procedures. Furthermore, the synthesized DES excellent recyclability, allowing for its reuse up to five times without any significant loss of functionality. Moreover, the synthesized DES demonstrated exceptional recyclability, enabling it to be reused up to five times without experiencing any notable decline in its effectiveness or functionality.

In this study, we presents a novel method for bolstering the photocatalytic effectiveness of crystalline titanium dioxide (TiO₂) through the integration of graphitic carbon nitride (g-C₃N₄), creating a series of TiO₂/g-C₃N₄ nanohybrids (TiCN-NHs). Leveraging an economical and scalable pyrolysis technique, we crafted different ratios of these nanohybrids (TiCN-NHs-1, TiCN-NHs-2, TiCN-NHs-3, and TiCN-NHs-4) to optimize their performance in harnessing visible light for photocatalysis. Detailed spectroscopic examinations were performed to dissect the nanohybrids’ structural and morphological nuances, alongside their chemical interactions and states. The primary evaluation of these nanohybrids’ photocatalytic prowess was the degradation of a selected colored organic contaminant under visible light exposure. The TiCN-NHs showcased an unprecedented photocatalytic degradation efficiency, surpassing that of p-TiO₂ and bulk b-g-C₃N₄ by twelvefold and eightfold, respectively, under comparable conditions. This dramatic increase in photocatalytic activity is credited to the harmonious interface between TiO₂ and g-C₃N₄ within the nanohybrids, fostering a diminished bandgap and promoting efficient charge separation. Additionally, photoluminescence and density of state analyses, specifically focusing on valence band spectra under visible light irradiation, further confirmed these findings. The synergistic effects observed in TiCN-NHs not only enhance photocatalytic degradation rates but also spotlight the potential of these nanohybrids in solar energy conversion and environmental cleanup applications, offering a promising avenue for future research in sustainable technologies.

Facilitating the separation of photogenerated charges is a crucial process in photocatalytic degradation of pollutants. In this study, Bi₂O₃/In₂O₃ composites were prepared using a co-precipitation method and subsequently calcined at 400 ℃ for 1 h. The Mott-Schottky curves confirmed a p(Bi₂O₃)-n(In₂O₃) heterojunction was yielded. Due to the significant difference in Fermi levels between Bi₂O₃ and In₂O₃, an internal electric field was established at the interface, with field lines directed from In₂O₃ to Bi₂O₃. Under illumination, the excited electrons accumulated in the conduction band (CB) of In₂O₃, while holes gathered in the valence band (VB) of Bi₂O₃, promoting charge separation and enhancing quantum efficiency. The composite material exhibited the highest photocatalytic activity when the atomic percentage of Bi to In was 1:1, with the first-order reaction rate constant of BI-1 increasing to 0.0149 min⁻¹, which is 4.3 and 4.4 multiples higher than that of pure In₂O₃ and pure Bi₂O₃. Recycling experiments demonstrated that the photocatalytic composite possesses good reusability and structural stability.

Modified phosphogypsum (PG) was prepared via low-temperature thermal decomposition to remove fluoride ions from wastewater. This study discussed the effect of heat treatment (pyrolysis temperature and time) and operating conditions (initial fluoride ions concentration, dosage, solution temperature, and initial pH) on fluoride ions removal efficiency. The results showed that PG was most successful in removing fluoride at 140 ℃ for 5 h. At an initial fluoride ions concentration of 100 mg/L, a dosage of 10 g/L, a solution temperature of 20 ℃, and strongly acidic (pH=2) and neutral (pH=7) environments, the fluoride removal efficiency of the PG reached 93.9 % and 66.7 %, respectively. In addition, when the initial fluoride ion concentration was reduced (25 mg/L), the heat-treated modified PG exhibited inadequate fluoride removal (<40 %). Increasing the solution temperature and initial pH was not conducive to fluoride ions removal. SEM-EDS, TG-DTG, FTIR, XRD and XPS analyses showed that thermal decomposition at a low temperature transformed the calcium sulfate dihydrate (CaSO₄·2H₂O) in the PG into calcium sulfate hemihydrate (CaSO₄·0.5H₂O) with higher solubility, increasing the Ca²⁺ ions concentration in the solution and further removing the F^- ions via chemical precipitation. Quantitative X-ray diffraction (QXRD) analysis revealed that the concentration of CaSO₄·0.5H₂O in PG is highest when subjected to optimal heat treatment conditions (140 ℃ for 5 h). Therefore, simple low-temperature thermal decomposition treatment (140 ℃) reduced PG energy consumption and effectively removed fluoride ions from wastewater, achieving the purpose of “ waste-treating-waste”.

This works documents a new silica gel-supported nanocatalyst (Si@NSBPdNPs 3) with low Pd loadings for n-alkylation reactions at room temperature. Post synthesis characterisation using SEM-EDX and ICP techniques provided a quantitative assessment of palladium species. Additionally, TEM analysis unveiled an average palladium nanoparticle size of 5.87 ± 0.2 nm. In-depth X-ray Photoelectron Spectroscopy (XPS) analysis revealed its predominant composition as Pd(0) complexed to a Schiff base ligand on low cost silica matrix. The nanocatalyst exhibited high efficacy in the catalysis of n-alkylation (Michael addition) reactions with various α,β-unsaturated Michael acceptors, yielding the corresponding n-alkyl products at room temperature with exceptional yields. Notably, the catalyst exhibited good stability and could be easily separated from the reaction mixture. Moreover, the catalyst displayed recyclability potential, maintaining its original catalytic efficacy for up to seven cycles without any discernible loss.

Urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) are the key processes for implementing urinated water electrolysis and hydrogen green production, respectively. This contribution investigates the modification of commercial nickel foam (NF) with a nickel phosphate (NiPO/NF) heterostructure layer via anodizing in phosphate solution at various potentials (5, 10 and 15 V) as a simple and efficient route to boost the urea-assisted water electrolysis and hydrogen production in alkaline medium. The morphology and composition physicochemical characterisation of the phosphate layer exhibit aggregates of crystalline nanoparticles with interstitial mesoporous and macroporous networks with a mole composition ratio of 9.42: 1.0: 8.14 for Ni: P: O respectively. The electrochemical measurements revealed the NiPO/NF anodized at 10 V exhibits a superior electroactive surface area of 255 cm², a substantially higher urea oxidation current compared to pristine NF, achieving 20 and 500 mA/cm² at 1.35 and 1.6 V vs. RHE respectively and retained 100 % of activity during the urea electrolysis for more than 3 h. The electrochemical impedance analysis confirmed the alkaline urea oxidation reaction proceeded via indirect (EC) and direct mechanism and the CO₂ intermediates adsorption–desorption became the predominant reaction at more positive potential. The NiPO/NF anode employed in an H-shape can deliver up to ±400 mA/cm² for UOR/HER at a bias potential of 1.85 V and 8-fold (2.0 mmol/min) much higher hydrogen production rate compared to the pristine NF anode (0.25 mmol/min). Combining commercial nickel foam modification via anodizing and alkaline urea electrolysis at ambient conditions offers a unique and innovative solution for both large-scale hydrogen green production as well as remedy of the urinated wastewater for a more sustainable future.

Herein, durable multi-functional silk is successfully prepared via in-situ clustering of nanopalladium, under the assistance of infrared irradiation. Whereas, the produced fabric acquired superior antimicrobial, UV-resistance and self-cleaning potentialities. Different instrumental analyses were performed, to reveal that; size average of nanopalladium was ranged in 8.6–21.4 nm. Additionally, increment in the nanopalladium concentration reflected in observable improvement of the mechanical properties, color strength and thermal stability. Yellowish degree was significantly increased from 22.36 for silk finished with 100 ppm of nanopalladium (silk-Pd-1) to 42.52 for silk finished with 300 ppm of nanopalladium (silk-Pd-3). Functional treatment of silk with higher concentrated nanopalladium exhibited the highest microbicide action even after 5 washing cycles, the microbial reduction percentage was evaluated to be 67 %, 65 % & 70 % against “St. Aureus, E. Coli and C. Albicans”, respectively. Ultraviolet protective factor (UPF) was superiorly evaluated for silk-Pd-3 to be 98.1 and 40.4 before and after 5 washing cycles. The aid of nanopalladium for acquiring the prepared silk the self-cleaning property as add-function was approved via kinetic study to show that the prepared fabrics exhibited good self-cleaning character by successive in-clustering of nanopalladium, while, t_1/2 for dirt removal was 190.9 min.

The combination of heterocycles renders a new possibility to synthesize multicyclic compounds having improved biological activities. Furo[3,2-b]pyridine is a fused heterocyclic ring system comprising a furan ring attached at the third and second positions of pyridine. These heterocyclic compounds can be easily synthesized from versatile starting materials including pyridine, furan, benzofuran, and benzopyridine via cycloaddition, cycloisomerization, multicomponent, cross-coupling, and Dakin-type reactions by utilizing microwave, copper, and palladium based catalysts. Among the chemical transformations of furo[3,2-b]pyridine derivatives, the review covered acetylation, addition, condensation, chlorination, Suzuki coupling, Vilsmeier-Haack reaction, and nucleophilic substitution reactions. Furo[3,2-b]pyridine has attracted remarkable attention from researchers due to its wide range of pharmacological and biological applications as antibiotic, antiviral, antifungal, anticancer, inhibitors of nicotinic acetylcholine receptors, CLKs, e1F4A, DYRKIA, α-glucosidase and β-glucosidase. The purpose of the review is to discuss the chemistry of the title reported during 2019–2024.

α-Glucosidase and urease inhibitors have emerged as crucial for developing therapeutic drugs targeting diabetes and gastrointestinal disorders. This study reports on new series of ibuprofen and mefenamic acid Schiff base derivatives incorporating isatin as dual inhibitors of α-glucosidase and urease enzymes. These synthesized derivatives (7a-r) were structurally characterized by ¹H NMR, ¹³C NMR and HRMS (EI). Biological evaluation (IC₅₀) identified several derivatives i.e., 7a (urease = 17.37 ± 1.37 µM, α-glucosidase = 44.1 ± 1.15 µM), 7j, (urease = 16.61 ± 1.37 µM, α-glucosidase = 81.2 ± 1.33 µM), 7o, (urease = 18.63 ± 1.27 µM, α-glucosidase = 70.3 ± 1.14 µM), 7r (urease = 11.36 ± 1.32 µM, α-glucosidase = 39.3 ± 1.17 µM), as dual inhibitors of urease (thiourea 21.37 ± 1.76 µM) and α–glucosidase (acarbose 375.82 ± 1.76 µM) enzymes. These bioactive derivatives were explored for cell viability studies against mononuclear cells revealing a good cytocompatibility. In silico molecular docking studies were also conducted to predict the binding mode of new derivatives with target enzymes that were found consistent with the results of in vitro research.

Herein, magnesium sulphide (MgS) electrode material (EM) is deposited on nickel-foam (NF) placed at 16 and 17 cm away from the raw material by simple powder vapour transport method. The increasing source to substrate distance (SSD) not only changed the structural parameters but also changed the nanofibers to cauliflowers like surface morphology. The cauliflowers like MgS/NF EM exhibited high specific capacitance (6339 F/g) as compared to the specific capacitance (1677 F/g) of nanofibers like MgS/NF EM. The cauliflowers like EM is showed high energy density of 220–99 Wh/kg, power density of 250–2500 W/kg, equivalent series resistance of 0.95 O and capacitance-stability of 93 % even for 10,000 cycles. The increasing SSD is fruitful for the increment in diffusion rate as confirmed by shifting of electrochemical impedance spectrum to y-axis, Dunn’s model and power law simulations. The diffusive contribution is 88/82 % at 5 mV/s which become 63/50 % at 100 mV/s for the cauliflower/nanofibers like EM. Moreover, the cauliflowers like EM have both battery and capacitive nature as 0.5 < b < 1 predicted by power law simulations. Additionally, the configured asymmetric supercapacitive (ASC) device is presented the specific capacitance of 834 F/g, energy density of 354–247 Wh/kg and power density of 2625–26250 W/kg. The ASC device could maintain the Coulombic-efficiency of 99 % and capacitance stability of 93 % even for 10,000 cycles. The excellent pseudocapacitive behaviour of MgS/NF EM enables them to use in the lithium ion battery and supercapacitor devices.