A highly efficient diazotization of diazoacetates with para-quinone methides has been established via a tetrabutyl ammonium bromide (TBAB)-catalyzed 1,6-conjugated addition pathway. This methodology affords a convenient, safe, and rapid way to generating diverse polysubstituted α-diazocarbonyl compounds, displaying good functional group tolerance, high atom economy, and easy accessibility.
Recently, tungsten disulfide (WS2) has received considerable attention in aspects of electrocatalytic oxygen evolution reactions (OER). However, due to the restricted number of active sites, WS2 nanoflower has a high overpotential in OER. Thus, we provide herein a doping approach for doping WS2 nanoflower with non-noble aluminum (Al) metal to increase active sites in an effort to enhance the OER activity of WS2. The positive electrocatalytic effect of Al-doping on WS2 material results in a lower OER operating overpotential. In comparison to undoped WS2, the skeleton-like structure (0.04 %) Al-doped WS2 nanoflowers significantly enhanced OER catalytic activity with an overpotential of 650 mV at the current density of 6 mA cm−2. Furthermore, the impact of different mass loadings of (0.04 %) Al-WS2 on the OER performance has been examined using electrochemical analysis. The success of using aluminum dopants to improve OER performance would have a significant impact on the development and production of non-noble metal sulfide-based electrocatalysts for OER.
The use of biomass as a renewable, sustainable, and eco-friendly energy source is now widely recognized as a potential solution for a variety of environmental problems. To develop biodiesel production, cost-effective feedstocks such as agricultural waste, food waste, and non-edible/waste cooking oil were utilized. A heterogeneous solid base catalyst was synthesized by calcining a mixture of waste golden apple snail shell (Pomacea canaliculata) and cultivated (Musa sapientum) banana peel. In transesterification process, potassium oxide (K2O) derived from banana peel is used as a cocatalyst to improve the catalytic activity of calcium oxide (CaO) catalyst derived from waste shell. The innovative CaO-K2O catalyst was investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF) and the Brunauer-Emmett-Teller (BET) technique. The morphology and elemental composition of calcium (Ca), potassium (K), and oxygen (O) in the catalyst were validated by field emission-scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). The CaO catalyst exhibited a BET surface area of 10.88 m2/g, which was enhanced to 14.62 m2/g upon combination with K2O. The Hammett indicator of CaO catalyst fell between 7.2 < H_< 9.8. However, the CaO-K2O catalyst exhibited a higher value of 15.0 < H_< 18.4, which could be attributed to the phase transition from CaO to CaO-K2O. To investigate the effects of catalyst concentration, ethanol/oil molar ratio, and transesterification time on the yield of fatty acid ethyl ester (FAEE). The optimal conditions for FAEE synthesis were determined using a central composite design (CCD) approach with response surface methodology (RSM). The regression equation obtained for the CCD model has a determination coefficient (R2) of 0.9921, indicating that this model is well-fitted. At 3.69 wt% catalyst concentration, 19.48:1 ethanol/oil molar ratio, and 1.80 h transesterification time, the highest FAEE yield from Jatropha Curcas oil (JCO) of 97.06 % was obtained. The novel catalyst has a strong yield and can be utilized for up to 6 cycles. It was found that the corresponding yield was 90 % when employing the same process parameters, demonstrating the high reusability of this catalyst. The biodiesel produced from non-edible JCO meets the criteria for standard biodiesel (ASTM D-6751 and EN 14214). The CaO-K2O catalyst is inexpensive, easy to make, biodegradable, recyclable, and environmentally friendly because it is derived from a biological residue. Because of these characteristics, it may be an appropriate candidate for the role of “green catalyst” in sustainable energy production.
The target compounds 4-(((1H-heteraryl)imino)methyl)-N,N-bis(4-(((4-((4-nitrophenyl) diazenyl)phenyl)imino)methyl)phenyl)aniline (7a-q) were prepared starting with 4,4′-diformyltriphenyl amine (2) which subjected to react with N-bromosuccinimide to give bromodiformyltriphenyl amine (4). Compound 4 reacted with two moles of 4-nitro-4′-aminoazobenzene to give the di-Schiff base 5. Compound 5 converted to its corresponding formyl derivative 6 by reaction with n-BuLi. The reaction of the formyl derivative 6 with seventeen amino heteraryl compounds afforded the target compounds 7a-q. All the newly prepared compounds were characterized by different spectroscopic and elemental analyses. Compounds 7a-q were screened for their antimicrobial activities against yeast-like fungi (C. albicans), Gram-negative (GN) bacteria (P. aeruginosa and E. coli), and Gram-positive (GP) bacteria (S. thuringiensis and B. subtilis). Compounds 7d, 7k, 7l, and 7q showed the highest activity against Gram-positive bacteria. The results of antimicrobial activity showed that it is highly affected by the used amine basicity.
A new composite material, ZnO/Yb2Zn-TiO6@g-C3N4 has been synthesized by simple hydrothermal process. This composite has been characterized using various material characterization techniques and was found to have a heterojunction amongst Yb2Zn-TiO6 and g-C3N4, leading to higher light absorption and poorer charge carrier recombination rates. Furthermore, the evaluation of the charge carrier density revealed that the incorporation of small sized ZnO (40 nm) into Yb2Zn-TiO6@g-C3N4 led to heightened disintegration of the photoinduced charge carriers. This observation implies that the presence of said metal oxide enhances the photocatalytic performance by greatly promoting the effective separation of charge carriers for various applications. When tested with bromothymol blue, the 20 wt% ZnO/Yb2Zn-TiO6@g-C3N4 composite showed a photodegradation rate several times greater (98 %) than individual ZnO, C3N4 and Yb2Zn-TiO6, respectively. The degradation efficiency of the ZnO/Yb2Zn-TiO6@g-C3N4 nanostructure in the absence of light was 24 %. The increased photoactivity of the composite material is due to the efficient separation of charge carriers and also due to the high redox capabilities resulting from the heterojunction. The composite also demonstrated stable photocatalytic performance over five cyclic runs and was effective in treating real printed ink wastewater. Furthermore, ZnO/Yb2Zn-TiO6@g-C3N4 was found to have excellent antibacterial properties in opposition to Escherichia coli, (Inhibition = 16(±0.2) mm) as well as Bacillus subtilis (Inhibition = 22(±0.3) mm). The MIC of the said nanomaterials against Escherichia coli as well as Bacillus subtilis were 50 µg/mL and 30 µg/mL respectively. The detailed explanation of the photodegradation mechanism was also provided. The use of this composite material can help to reduce the harmful effects of contaminants and microbes in aquatic environments and promote environmental sustainability.
In this research, zeolite ZSM-12 with Si/Al ratio = 80 was synthesized by hydrothermal method. The synthesized zeolite ZSM-12 was modified using Fe and Ga metals and a combination of these two metals, 1 % iron metals (Z80-Fe) and 1 % gallium metals(Z80-Ga), and a 2 % combination of these two metals (Z80-Fe-Ga). The physicochemical properties of synthesized zeolites were evaluated and compared by XRD, EDX-dot-mapping, NH3-TPD, BET, FT-IR, and TGA analyses. The catalytic assessment of synthesized zeolites in the HTO (n-hexane to olefins) process in a fixed bed reactor under atmospheric pressure and Weight hourly space velocity (WHSV) equal to 4 h−1 at 550 °C was evaluated. Various parameters such as selectivity towards light olefins, propylene to ethylene (P/E ratio), production of light alkanes, and aromatic compounds (BTX) were investigated. The results show that using metals led to the improvement and adjustment of the acid sites of zeolite, and the highest amount of light olefin and the lowest amount of coke were obtained. The result of the n-hexane to olefin process showed that the yield of light olefins was significantly improved in all modified catalysts compared to parent zeolite MTW. Compared to other modified zeolites, Z80-Fe-Ga zeolite has the highest yield of light olefins, equal to 59 %. This zeolite performs better due to the presence of gallium and iron metals and shows the highest propylene selectivity (P/E = 2.4). In addition, according to the results of the TGA analysis, the content of coke on the Z80-Fe-Ga catalyst after the catalytic reaction is much less than that of other catalysts after the catalytic reactor test.
Facilitating energy resource deficiency and environmental contamination, this work focuses on sustainable biodiesel production through the esterification reactions of oleic acid (OA) with methanol. To address the reaction, a novel heterogeneous acid catalyst, 12-tungstophosphoric acid (TPA) immobilized on Sn-based MOFs (Sn(II)-BDC) was synthesized via a simple, green solvent, and easy-to-implement synthesis strategy for the first time, and applied effectively for esterification process of OA to produce biodiesel. The structure and composition of as-obtained catalyst have been verified using XRD, FTIR, N2 physisorption, SEM, EDX, TG, Py-FTIR, TPD-NH3, and XPS techniques. The obtained TPA/Sn(II)-BDC catalyst was found to be the best with 60 wt% of TPA loading, which resulted in an OA conversion of 91.7 % at optimized conditions of 0.15 g catalyst loading and methanol to OA molar ratio of 20:1 at temperature of 120 °C in 4 h, and the excellent performance arises from available pores structure, large amounts of acidic sites, good stability and the synergistic catalytic effect of TPA and Sn(II)-BDC. Furthermore, the composite catalyst reusability has been studied for five cycles, and it exhibits an acceptable conversion. This research provides a green and large-scale synthesis route for the sustainable production of biofuels by constructing heteropolyacids/Sn-based MOFs synergistic catalysts.
The conversion of organic waste into valuable commodities is essential for safeguarding the environment and promoting the sustainable development of the economy. This investigation centres on the production of Zinc ferrite nanoparticles (ZnF NPs), modified eggshells (MES) impregnated with chitosan (CS) and coated with poly ortho-toluidine P(OT) nanocomposites (NCs). This synthesis involves a quaternary composition denoted as P(OT)/MES/CS/ZnF NCs, achieved through chemical polymerization techniques. The resulting NCs were characterized and applied for the removal of Brilliant Green (B.GR) and Acid Red (A.RE). Four distinct compositions, namely pure P(OT), binary P(OT)/MES, ternary P(OT)/MES/CS, and quaternary P(OT)/MES/CS/ZnF NCs, were synthesized. The outcomes revealed that the quaternary P(OT)/MES/CS/ZnF NCs exhibited the highest adsorption capacities for B.GR and A.RE at)27.03 and 142.8 mg−1(, respectively. The findings revealed that the most favorable parameters for the removal of A.RE were attained at a pH of 2, using 15 mg of P(OT)/MES/CS/ZnF NCs at a concentration of 25 mg/L for a duration of 120 min. On the other hand, when it comes to removing B.GR, the best results were shown while using 15 mg of P(OT)/MES/CS/ZnF NCs at a concentration of 5 mg/L for 120 min, specifically at a pH of 6. The greatest real wastewater removal efficiencies for A.RE dye and B.GR dye, respectively, were found to be 99.5% and 97.6% under these operating circumstances. These optimal quaternary NCs demonstrated the ability to be regenerated four times without significantly compromising their adsorption properties and exhibited a remarkable capacity to remove 96–98% of dyes from real polluted water. Through the use of regression data and a pseudo-second-order model, the adsorption kinetics were explained, with R2 values of 0.994 for A.RE and 0.993 for B.GR, respectively. Thermodynamic parameters of dye adsorption by the NCs affirmed the fact that adsorption occurs spontaneous and have endothermic nature. This study underscores an effective synthesis approach applicable for large-scale production of new adsorbents for water treatment purposes.
Eugenol, a primary component of clove oil, is a compound of considerable interest in medicinal chemistry due to its demonstrated potential as an effective agent in various therapeutic applications. In this study, a series of eugenol derivatives were designed and synthesized based on the hybridization of eugenol with 1,2,3-triazole and chalcone moieties. Compound 5j and 5k were denoted as lead structures against Mycobacterium tuberculosis Shikimate Kinase (MtSK). Moreover, the docking studies indicated that both the eugenol and triazole fragments in compound 5j and 5k played a pivotal role in the inhibition activity of MtSK, owing to their binding interactions with Arg58, Pro118, and Arg136 residues. Furthermore, in silico drug-likeness prediction analysis suggested that the majority of the synthesized compounds exhibit good oral bioavailability based on their molecular properties and Lipinski’s Rule of Five predictions.
2H-azirines have represented versatile building motifs in the domain of organic chemistry owing to their excellent reaction activity induced by the high strain of the three-membered ring species. Over the past decades, brilliant achievements have been made in 2H-azirine chemistry involving the construction as well as the transformation of such functional compounds. In the presence of transition metals, strong bases or oxidants, 2H-azirines could be converted into the corresponding products under harsh reaction conditions. Different from traditional catalytic methods, the utilization of photochemistry has proved to be an extremely fascinating protocol that facilitates the construction of 2H-azirine blocks from diverse substrates and further conversion into various derivatives with interesting biological activities. In this regard, more and more light-driven synthetic approaches featuring high efficiency and mild conditions have been developed. Herein, we summarized the accessibility and applications of 2H-azirines as powerful precursors or key intermediates for the synthesis of biologically promising molecules in the presence of photocatalytic conditions.
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