Research on Chemical Intermediates最新文献

The development of multifunctional materials is essential due to the increasing demand for efficient energy storage and effluent remediation. In this study, a hybrid nanostructure comprising graphitic carbon nitride (g-C₃N₄) and Cu–ZnS was synthesized to function as a dual-purpose material for photocatalytic degradation and supercapacitor applications. The formation of a mixed-phase Cu–ZnS/g-C₃N₄ composite with both cubic and hexagonal ZnS structures was confirmed by powder X-ray diffraction (XRD). The uniform dispersion of Cu–ZnS nanoparticles over g-C₃N₄ sheets was demonstrated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. BET analysis indicated a 1.6-fold increase in surface area (148.16 m²/g) for CuZnS-GCN25 compared to bare CuZnS. Electrochemical evaluation showed that CuZnS-GCN25 delivered a high specific capacitance of 275 F g⁻¹ at 1 A g⁻¹, excellent cycling stability (92.5% after 10,000 cycles) and 70% capacitance retention at 20 A g⁻¹ in a two-electrode setup. In photocatalytic testing, CuZnS-GCN25 achieved 92.4% degradation of amoxicillin (AMX) within 60 min under visible light, following pseudo-first-order kinetics with a rate constant of 0.029 min⁻¹. These results highlight the potential of CuZnS-GCN25 as a high-performance, eco-friendly material for integrated energy and environmental remediation systems.

The present work focuses on the synthesis and catalytic evaluation of Ag nanoparticles supported on mesoporous CaO/SBA-15 (Ag/CaSBA-15) catalysts for the selective dehydrogenative coupling of benzyl alcohol and aniline to produce N-benzylideneaniline (NBA). A series of CaO and Ag-modified SBA-15 catalysts with varying Ag loadings (2.5–10 wt%) were synthesized via the impregnation method and systematically characterized using XRD, TG-DSC, FT-IR, CO₂-TPD, BET, XPS, and TEM. Powder XRD and BET analysis confirm the retention of mesoporous structure of SBA-15 after modification with CaO and Ag. The pore size distribution is narrow, with peak maxima around 8–9 nm. Additionally, the average crystallite size of Ag determined by XRD (~ 12 nm) aligns well with TEM observations (average size ~ 10 nm). The optimized catalyst (5Ag/CaSBA-15) exhibited 98% conversion of benzyl alcohol with > 99% selectivity to NBA at 120 °C under solvent-free conditions. Analysis by TEM, XPS, XRD, N₂ sorption, and pore size by BET confirmed the uniform dispersion of Ag NPs. High-resolution TEM images also highlight the interconnected morphology of the CaSBA-15 support and the embedded Ag NPs. Various benzyl alcohol and aniline substrates were efficiently converted into their corresponding imines, achieving good to excellent yields. Furthermore, the catalyst exhibited excellent reusability, maintaining high performance over 5 reaction cycles with minimal structural degradation.

In this work, one-pot pseudo four-component synthesis of pyrido[2,3-d:6,5-d′]dipyrimidines from various aldehydes (1 mmol), 2-thiobarbituric acid (2 mmol), and ammonium acetate (1.2 mmol) in deep eutectic solvent (DES) named ChCl/THFTCA (choline chloride and tetrahydrofuran-2,3,4,5-tetracarboxylic acid) has been developed under ultrasonic irradiation. A wide range of pyrido-dipyrimidines can be synthesized with excellent performance in the biodegradable eutectic solvent ChCl/THFTCA-DES under optimized conditions (1 mL of DES, 25 °C, ultrasonic: 30 W), which is simple in operation and compatible with functional groups (1a-17a, 9–20 min, 89–98%). The DES both acts as a green medium for this reaction and as a catalyst, and can be recovered and reused up to six times with negligible activity loss. Also, green chemistry metrics were merged in this method, confirming its adherence to sustainable synthesis approaches and emphasizing its environmental compatibility. Synthesis and characterization of novel derivatives, brilliant metrics of green chemistry, introducing an efficient catalytic system by integrating the catalytic effect of a DES and ultrasonic irradiation, and the first report of the synthesis of the above derivatives in an efficient DES according to our research are the novel aspects of our approach.

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This study explores the novel synthesis of triazoles utilizing a Co₃O₄/g-C₃N₄/Si catalytic system under microwave irradiation. The unique properties of cobalt oxide, graphitic carbon nitride, and silicon provide a synergistic effect that significantly enhances reaction efficiency. Microwave irradiation allows for rapid and uniform heating, activating reactants and facilitating the formation of reactive intermediates. This study investigates the preparation and catalytic efficacy of nano Co₃O₄ doped g-C₃N₄ mixed with tert-butyldimethylsilyl chloride catalysts in the [3 + 2] cycloaddition reaction for the formation of 1,2,3-1H-triazole derivatives. Utilizing ethanol/water mixture as a solvent not only facilitates faster reaction rates but also provides an environmentally friendly, non-toxic, and cost-effective medium. Under all studied conditions, the Co₃O₄/g-C₃N₄/Si NCs exhibited better catalytic performance than Co₃O₄ NPs, allowing the sole production of the desired 1,4-isomer. Interestingly, the Co₃O₄/g-C₃N₄/Si NCs produced noticeably greater yields (91–97%) for a variety of triazole compounds under microwave irradiation than did the Co₃O₄ NPs (49–75%). The purity of the triazole compounds and the effective synthesis of the NCs were validated by characterization procedures. The high efficiency and heterogeneity of the Co₃O₄/g-C₃N₄/Si nanocatalyst allowed for simple isolation and repurposing. The results demonstrate that this method not only increases yield and reaction rates but also offers milder conditions compared to conventional synthesis techniques, presenting a promising approach for the efficient production of triazole compounds in organic synthesis.

Water pollution with dyes can cause many problems for humans and the environment. So, the treatment of water using simple and effective methods has attracted significant attention recently. In this research, activated carbon (AC)/Fe₃O₄/ZnO recyclable, non-toxic, and cost-efficient nanocatalysts were synthesized using a simple hydrothermal method. XRD, EDS, FT-IR, VSM, TEM, and analysis characterized the structural properties of the synthesized AC/Fe3O4/ZnO nanocomposites. XRD, FT-IR, and EDS results confirmed that AC/Fe₃O₄/ZnO nanocomposites were synthesized successfully. FESEM and TEM analysis images showed that Fe₃O₄ and ZnO were grown spherically on activated carbon micro-porous substrates. The photocatalyst activity of AC/Fe₃O₄/ZnO nanocomposites was studied by methylene blue dye under UV irradiation. The results confirmed that AC/Fe₃O₄/ZnO nanocomposites had high performance in the fast photodegradation of methylene blue dye, and 10 ppm methylene blue dye was degraded in 4 min. Based on this research, AC/Fe₃O₄/ZnO nanocomposite is a high-performance and non-toxic nanocomposite for the removal of methylene blue dye from water.

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The main goal of this study is the development of non-precious, highly effective, stable photocatalysts for the degradation of organic dyes. In this work, we utilize a strategy to regulate the surface and structure of catalysts to boost the photocatalytic activity and stability through A-site deficiency of La_1-xCoO₃ perovskites. We fabricated a novel perovskite structure with a nominal composition of La_1-xCoO₃ (x = 0 and 0.1) using a facile sol–gel method. Comprehensive characterization of the fabricated samples was performed using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, and UV–Vis spectroscopy. XRD confirmed the formation of LaCoO₃ and La_0.9CoO₃ at 750 °C, both exhibiting a rhombohedral phase structure. FTIR analysis revealed characteristic bands at 585 cm⁻¹ and 520 cm⁻¹, corresponding to the M–O–M reflection mode and M–O stretching vibrations, respectively. SEM micrographs showed pseudo-spherical grains with varying sizes and porosities for both samples. BET analysis further demonstrated specific surface areas of 9.58 m²/g for LaCoO₃ and 11.24 m²/g for La_0.9CoO₃. Optical and photocatalytic investigations indicated that the two materials possess semiconductor properties, with LaCoO₃ and La_0.9CoO₃ exhibiting band gaps of 2.78 eV and 2.64 eV, respectively. Photocatalytic tests under visible light revealed significant degradation of the model dyes; LaCoO₃ achieved removal efficiencies of 56.41% for MB and 91.45% for NR, while La_0.9CoO₃ demonstrated superior performance, reaching 80.07% degradation of MB and 98.16% of NR. These findings underscore the enhanced catalytic efficiency of La_0.9CoO₃ compared to LaCoO₃, making it a promising candidate for the photodegradation of organic pollutants under visible-light irradiation.

We have developed an efficient and high-yielding protocol for the synthesis of pyrano[2,3-d]pyrimidines via a one-pot, multicomponent reaction of aldehyde(s), malononitrile, and thio-barbituric acid or barbituric acid in aqueous medium, utilizing a Brønsted acid-hydrotrope combined catalyst (BAHC). This catalytic system was further extended to the synthesis of isoindolo[2,1-a]quinazolines through a multicomponent reaction of various amines, isatoic anhydride, and 2-carboxybenzaldehyde, furnishing the desired products in good yields. Key advantages of present method include high atom economy, energy efficiency, the use of water as a sustainable reaction medium, operational simplicity, and the elimination of organic solvents, making it an eco-friendly and practical approach for synthesis of complex heterocyclic compounds.

The composite regenerated cellulose membranes (CRCMs), a combination of regenerated cellulose membrane (RCM) with titanium dioxide (TiO₂), offer an effective solution for wastewater treatment by facilitating easy recovery and reuse of photocatalysts. In contrast to other synthesized polymer membranes, CRCMs not only ensure the good dispersion of TiO₂ but also exhibit excellent photoactivity and are made from eco-friendly materials. The fabrication process involved adding TiO₂ immediately after dissolving microcrystalline cellulose in a tetrabutylphosphonium hydroxide/dimethyl sulfoxide solution. The membranes were then cast and coagulated with propylene carbonate. The objective of this study was to optimize TiO₂ content per membrane and thoroughly investigate the resulting properties and photoactivity of the CRCMs. The X-ray analysis showed that CRCMs were successfully incorporated without change in the phase composition. By scanning electron microscopy images, as the TiO₂ content increased (from 0 to 20 mg), the membrane thickness increased in the order 63.1, 97.9, 110.5, 136.3, and 143.1 µm, respectively. Notably, when the content was 15 mg and 20 mg per membrane, TiO₂ agglomeration occurred, and the photocatalytic efficiency decreased. The CRCM with 10 mg TiO₂ (CRCM10) was considered the optimal membrane due to the highest permeability (16.3 L.m⁻².h⁻¹.bar⁻¹) and the best methylene blue (MB) removal ability (about 96% after 180 min of decomposition). Conversely, higher TiO₂ content proved unfavorable for photoactivity, with CRCM15 and CRCM20 showing significantly lower MB removal efficiencies of 59.7% and 42.2%, respectively. The reusability of CRCM10 was stable, maintaining an MB removal efficiency of 80% after four cycles. This research offers an environmentally friendly, cost-effective, and scalable approach for wastewater treatment.

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Photocatalytic degradation of resistant antibiotics based on metal sulfide is regarded as an important method of wastewater treatment. However, the low photocatalytic activity and photocorrosion of CdS restrict its application in the photocatalytic degradation of resistant antibiotics. In order to comprehensively investigate the impact of co-doping transition metal ions into CdS on its photocatalytic activity, we successfully prepared a Fe³⁺/Co²⁺/Ni²⁺ co-doped CdS catalyst (Fe_0.1Co_0.05Ni_0.05/CdS) featuring a lamellar agglomeration structure. The specific surface area of Fe_0.1Co_0.05Ni_0.05/CdS (77.0 m²·g⁻¹) was increased evidently, while pure CdS was only 44.3 m²·g⁻¹. Additionally, the photocatalytic degradation efficiency of tetracycline hydrochloride (TCH) by Fe_0.1Co_0.05Ni_0.05/CdS was significantly enhanced, and the TCH’s removal rate can reach 88.9% within 50 min. This is due to Fe³⁺ doping altering CdS's bandgap for more visible-light absorption, Co²⁺ addition reducing electron–hole pairs recombination, and Ni²⁺ introduction enhancing photocorrosion resistance. Moreover, sample Fe_0.1Co_0.05Ni_0.05/CdS retained excellent photocatalytic stability after four cycles. The active species of h⁺ and ·O₂⁻ play the major role in TCH degradation; thus, we hypothesized the TCH’s photocatalytic mechanism and degradative pathway. This finding can assist in designing high-efficiency catalysts by co-doping non-noble metal ions, which will enhance the catalysts’ photocatalytic efficiency through their synergistic action.

Clay-supported green-synthesized nanoparticle-decorated heterogeneous catalysts offer an environmentally friendly and sustainable alternative to conventional homogeneous catalysts. In this work, we reported a green-synthesized NiTiO₃ nanoparticle decorated with MK10 clay surface, the composite prepared via ultrasonication method. The synthesized catalyst was used for the preparation of 1-phenyl-1H-tetrazole analogues via a microwave medium. Among the various loading percentages of the NiTiO₃/MK10 composite, 20%NiTiO₃/MK10 (M1NT20) showed good catalytic activity. The structural and morphological properties of the optimized M1NT20 heterogeneous catalyst were confirmed by various characterization techniques. The NiTiO₃ nanoparticles are evenly decorated on the surface of the MK10 clay, which was confirmed from FESEM & EDAX analysis. The average particle size and d-spacing value of the NiTiO₃ present in M1NT20 were calculated from HRTEM analysis ~ 0.295 nm and ~ 13.5 nm. The synthesized composite M1NT20 had a high surface area, and more surface-active sites were measured by BET analysis. Further, the reaction was optimized with respect to the solvent, temperature, and amount of catalyst. According to the green chemistry principle, microwave irradiation with a solvent-free system is a time-reducing and sustainable method for the synthesis of organic compounds. Synthesis of 1H-tetrazole in microwave medium presence of MINT20 heterogeneous catalyst at 60 °C under solvent-free condition shows 96% yield within 10 min and high turnover number and turnover frequency. The scale-up synthesis also showed high catalytic activity with good yield, and the recycle and reusability studies up to six cycles showed good yields.