Journal of Saudi Chemical Society最新文献

FeNbO₄ monoclinic nanocomposite semiconductors were synthesised using hydrothermal and sol gel methods; photocatalysts were then calcined at 800 °C. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy (UV/Vis) and X-ray diffraction (XRD) technologies were used to investigate crystallinity, morphology and optical properties of the photocatalysts. Fourier transform infrared spectroscopy (FTIR) was used to determine the functional groups of both treated and untreated FeNbO₄. It was found that the S. molle extract-treated FeNbO₄ prepared using the hydrothermal method (FeNbO₄-HT + S. molle) has the smallest nanoparticles (22.8 nm) with the smallest band gap energy (2.78 eV). X-ray photoelectron spectroscopy verified the presence of the elements of FeNbO₄ as well as their oxidation states. The photodegradation reactions of 10-ppm methyl orange dye solutions using FeNbO₄-sol gel, FeNbO₄-HT and FeNbO₄-HT + S. molle were carried out under visible light (>420 nm) for 50 min. The reactions resulted in degradation percent of 74 %, 78 % and 96 % by using FeNbO₄-sol gel, FeNbO₄-HT and FeNbO₄-HT + S. molle respectively. The photocatalytic activity of FeNbO₄ treated with S. molle extract demonstrated superior light absorption and photostability, which is attributed to the consistency in the photocatalysts’ morphology, optical band gap, particle size distribution, and porosity. The photocatalysts remained stable and effective for five degradation cycles.

A simple method for Michael addition at C-5 of Camptothecin has been developed to construct 5-CPT derivatives. The addition products were obtained with moderate yields, and the structures of the target compounds were characterized by ¹H NMR, ¹³C NMR, and HRMS spectra. The feasibility of various Michael addition acceptors for this reaction has also been investigated.

The synthesis and biological assessment of 2,5-disubstituted-1,3,4-oxadiazoles derivatives from amino acids as new potential antibacterial and antioxidant agents have been reported. The structures of the new synthesized compounds were characterized based on physicochemical and spectral data UV–Visible, IR, ¹HNMR, ¹³CNMR. All the target compounds were screened for their in vitro antibacterial activity against three Gram-positive bacterial strains, namely Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Listeria innocua ATCC 33090, and two Gram-negative bacterial strains, namely Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, and antifungal activity against Candida albicans ATCC 10231 in comparison with Amoxicillin, Tetracycline, Gentamicin and Oxacillin. The only compound 1-{(4S)-4-amino-4-[5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]butyl}guanidine 5e with the amine radical that showed excellent results against all bacteria, particularly against L. innocua (IZ = 12 mm), has excellent antifungal activity (IZ = 32 mm). The compounds 2-[5-(1-amino-3-methylbutyl)-1,3,4-oxadiazol-2-yl]phenol 5b and 2-[5-(pyrrolidin-2-yl)-1,3,4-oxadiazol-2-yl]phenol 5j have excellent activities (IZ = 27 and IZ = 28 mm, respectively) against B. cereus and P. aeruginosa. Compounds 2-{5-[(1R)-1-amino-2-sulfanylethyl]-1,3,4-oxadiazol-2-yl}phenol 5c, 2-{5-[(1S)-1-amino-3-(methylsulfanyl)propyl]-1,3,4-oxadiazol-2-yl}phenol 5d with the sulfur radical, 3--[5-(2-3-amino hydroxyphenyl)-1,3,4-oxadiazol-2-yl]propanamide 5g with the amide radical, 5j with the amino radical, and 4-amino-4-[5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]butanoic acid 5k gave good results against B. cereus, where 19 mm < IZ < 23 mm. We also found that compound 5j has the greatest activity (IZ = 33 mm) against C. albicans, followed by compounds 5e (IZ = 32 mm) and 5b (IZ = 30 mm). The synthesized compounds were also screened for radical scavenging antioxidant activities by DPPH, FRAP, and TAC assays and found to be good antioxidant agents. According to the IC50 values, all compounds demonstrated good to excellent activity, especially 5b and 2-{5-[1-amino-2-(1H-imidazol-4-yl)ethyl]-1,3,4-oxadiazol-2-yl}phenol 5i for DPPH, 5e and 5i for FRAP and methyl 2-hydroxybenzoate 2, 2-{5-[1-amino-2-(1H-indol-3-yl)ethyl]-1,3,4-oxadiazol-2-yl}phenol 5h with the imidazol group and 2-[5-(1,5-diaminopentyl)-1,3,4-oxadiazol-2-yl]phenol 5f with the imidazol group for TAC. All these compounds showed better activity than AA and BHT.

Herein, a novel magnetic visible-driven g-C₃N₄/TiO₂/CuFe₂O₄ nanocomposite with excellent photocatalytic performance was successfully prepared and employed for photodegradation of tetracycline. Several analysis including X-Ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), energy dispersive X-ray (EDX), Vibrating-Sample Magnetometer (VSM), and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV–Vis DRS) were performed in order to study the structural, optical, magnetic, as well as morphological properties of nanocomposite. The optical band gap of g-C₃N₄/TiO₂/CuFe₂O₄ heterostructure was found to be red shifted to 2.45 eV from 3.15 eV for pure TiO₂. Enhanced separation of photoinduced electron-hole pairs and enhanced visible light absorption capacity of nanocomposite lead to a maximum tetracycline photodegradation efficiency. Response surface methodology (RSM) was used to investigate the influence four independent variables, including initial photocatalyst dosage (7–14 g/L), TC concentration (20–30 ppm), solution pH (5.5–7.5), and irradiation time (20–40 min), and optimize the TC degradation efficiency. The g-C₃N₄/TiO₂/CuFe₂O₄ nanocomposite was able to separate and recycle easily using an external magnetic field, and the results of reusability was shown its high stability after 5 cycles. Active species trapping experiments suggested that holes and hydroxyl radicals played a crucial role in the TC degradation process. Finally, a potential photocatalytic mechanism for photodegradation of TC was proposed.

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.