Chemical Papers最新文献

This study presents two groundbreaking achievements in materials science with significant implications for advanced technologies. First, we report the successful mechanosynthesis of Zn₂Ti₃O₈ through a solvent-free, solid-state reaction between rutile-type TiO₂ and ZnO, yielding the compound after 8 hours of milling. Second, we demonstrate a novel reverse phase conversion of TiO₂ from rutile to anatase under extreme conditions, involving a highly alkaline (KOH) environment at 160 °C, followed by hydrothermal treatment and calcination at 850 °C. This unprecedented transformation enhances the anatase phase’s morphological, optical, and surface properties, offering substantial advantages for various applications. Comprehensive characterization using X-ray diffraction, UV–Vis, and FT-IR spectroscopy revealed crucial insights into the materials' structural and optical properties. Notably, bandgap energies estimated from Tauc plots showed a systematic decrease with increasing reaction time, ranging from 3.54 to 3.49 eV for 2 to 10 hours, respectively. Our findings contribute significantly to the field by introducing an environmentally friendly Zn₂Ti₃O₈ synthesis route, challenging conventional phase stability understanding, and providing a method for precise bandgap control. This research not only advances fundamental knowledge but also opens new avenues for developing high-performance materials in energy and environmental applications, potentially revolutionizing next-generation technologies.

A carbocatalytic, regioselective synthesis of C₃-N alkylated coumarins has been reported under solvent-free conditions. This synthetic protocol provides a series of C₃-N alkylated coumarins in good yields starting directly from coumarins and azides in the presence of GO nanosheets without any additives or ligands needed. In contrast to the frequently applied synthetic strategy that involves nucleophilic substitution of benzylamine/benzyl alcohol with halogenated coumarins in the presence of Pd or Cu catalyst for the generation of N-alkylated coumarins, here, coumarins directly reacts with azides via azide-alkene 1,3-dipolar cycloaddition/ring cleavage/1,2-H migration/denitrogenation, followed by 1,3-H migration to afford C₃-N alkylated coumarins.

This study examines the properties of indium-based thermodynamically delafossites, namely XInO₂ (where X = Na, K), in their trigonal phase using GGA and mBJ techniques inside the DFT framework. It proves that these materials have an apparent bandgap that is indirect. The bandgap for NaInO₂ is 1.90 (GGA-PBE), 3.98 (mBJ), and 1.80 (GGA-PBE), 3.69 (mBJ) for KInO₂. Stability was assessed using phonon band structures and molecular dynamics simulations; thermodynamic characteristics were examined using variables including heat capacity, enthalpy, entropy, and free energy. The optical characteristics of these materials were also investigated, and a range of factors, including refractive index and dielectric functions, were evaluated. Using BoltzTrap code analysis, the research looked at these material’s temperature-dependent characteristics in more detail. It focused on the materials thermal and electrical conductivities, the Seebeck coefficient, and other pertinent metrics. The first-principles calculation of the optical and thermoelectric characteristics offers a new direction for further experimental research on their use in renewable energy devices.

Quinazolin-4(1H)-one derivatives have shown potential in various therapeutic areas, including cardiovascular diseases because of their antihypertensive effects. Therefore, synthesis of these heterocyclic compounds is of prime importance. The NiO@Fe₃O₄ nanophotocatalyst has been introduced as a novel mediator for the one-pot synthesis of some substituted quinazolin-4(1H)-one derivatives under illumination of a 200 W high-pressure mercury vapor lamp. The environmental-friendly nanophotocatalyst is biosynthesized using the extract of Glycyrrhiza glabra leaves and characterized through various analytical techniques such as XPS, VSM, FT-IR, XRD, FE-SEM, TEM, and EDS. The TEM analysis revealed the size of 20–45 nm for the prepared NiO@Fe₃. Optimization experiments proved that the condensation reactions can be achieved under aerobic conditions at room temperature with high to excellent yields with 1 mmol of 2-aminobenzamide and the corresponding aromatic aldehyde in the presence of 30 mg of NiO@Fe₃O₄ nanophotocatalyst in ethanol as a safe solvent during 20 min under irradiation. The stability and reusability of the photocatalyst were assessed, demonstrating its practical applicability and reproducibility.

Solid polymer electrolytes (SPEs) are a promising substitute, offering splendid benefits such as improved energy density and safety compared to liquid electrolytes. However, low ionic conductivity, poor mechanical strength, weak interfacial contact, and electrode metal corrosion may still be critical problems in SPEs. Here, a composite solid polymer electrolyte (CSPE) is prepared using the standard solution casting technique, incorporating P(VDF-HFP)-PVAc-LiTFSI-EC [poly(vinylidene fluoride-hexafluoro propylene)-poly(vinyl acetate)-lithium bis-trifluoromethanesulfonylimide-Ethylene carbonate] with hydrothermally derived spherical shape ZrO₂ nanocrystals (NCs) as a passive ceramic filler. Notably, incorporating 5wt% ZrO₂ NC in the CSPE leads to a notable threefold time increase in ionic conductivity compared to the SPE without ZrO₂ NC_. This improvement is mainly attributed to spherical shape ZrO₂ NC facilitating Li⁺ migration channels and immobilizing free anions, likely by suppressing the crystallinity of the CSPE and its Lewis acid–base nature. Additionally, CSPE demonstrates high mechanical strength; excellent thermal stability; a wide electrochemical window; and favorable electrolyte affinity. This promising material is well-suited for developing robust and efficient electrolytes for various applications.

This study targeted to generating composites comprised of sugarcane bagasse (SCB) and magnetic particles (MPs) under a facile and low-cost approach. Moreover, the adsorption performance of composites, treated SCB, and MPs for crystal violet (CV) was evaluated. Cellulose fibers were firstly isolated from SCB with a two-step process and employed as a matrix material to randomly adhere MPs via an in situ chemical co-precipitation method at room temperature. The properties of the composite were determined through analysis methods such as X-ray diffractometer (XRD), scanning electron microscopy with energy-dispersive X-ray analysis (EDX/SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET). Magnetization, surface area, and pore diameter of magnetic fiber composite were 11.1 emu/g, 20 m²/g, and 0.002 cm³/g, respectively. The characteristic peaks of cellulose and MPs were found in XRD results, whereas the Fe content in composite was 27.52%. FTIR spectra also exposed the characteristic functional groups of MPs and treated SCB. Additionally, the CV removal using composites was evaluated with the adsorption efficiency and capacity of 72.09% and 77.22 mg/g, respectively, at pH 7, an adsorbent dose of 2 g/L, a CV concentration of 150 mg/L within 30 min. The adsorption process corresponded to the Sips model and the pseudo-second-order kinetic model. Besides, the mechanism of CV adsorption was primarily characterized by heterogeneous adsorption on the surface and physical sorption. In short, the obtained composite was a promising adsorbent for treating the dye-containing wastewater.

Removing fluoride from contaminated water is critical to safe drinking water as it is one of the harmful elements to health. In this study, iron oxide nanoparticles (IONP) synthesized using an environmentally friendly method were used to defluoridate fluoride-contaminated water. This study used Camellia sinensis (tea) leaf extract as a reducing agent to produce IONP from natural magnetite. Scanning electron microscopy observations showed the formation of spherical and sub-spherical IONP aggregates in the range of 40–100 nm. With a contact time of 30 min at or near neutral pH, over 90% of the fluoride was removed from the aqueous medium when an adsorbate dose of 5 g/L was used. The fluoride removal agreed reasonably well with the pseudo-second-order kinetic model. Since the zero-point charge of the IONPs was 8.15, the fluoride adsorption was higher at acidic pH. The adsorption process was exothermic as the extent of defluoridation was on the order of 293 > 298 > 303 K. Coexisting chloride had an unfavourable effect on fluoride removal, but adsorption occurred quickly. The present study confirmed the successful synthesis of IONP from natural magnetite using tea leaf extract, representing a more environmentally friendly approach than existing methods. Since synthesized IONPs can effectively remove fluoride from water, this method can be used to develop a fluoride removal filter that can be used at the household level.

Antimicrobial resistance and cancer detection are two popular applications for cadmium bismuth sulfide nanoparticles. Cadmium bismuth sulfide nanoparticles have demonstrated antibacterial capabilities and a broad range of antibacterial activity against both gram-positive and gram-negative bacteria. To obtain more insights into its bonding and connectivity patterns, we calculate new Zagreb-type indices. To evaluate the material’s stability and predict its behavior in different situations, we can calculate the entropy measure. By using a quadratic regression model, we create mathematical connections between the Zagreb-type indices and entropy, which helps maximize its utilization in specific applications. Through the regression model, we see the relation between indices and entropy. In the present paper, a new application of quadratic regression models is presented in developing a mathematical relation between Zagreb-type indices and entropy measures to derive a new methodology for predicting and optimizing stability and behavior in cadmium bismuth sulfide nanoparticles. It connects molecular graph theory with material analysis in new ways toward deeper insights into molecular connectivity patterns and enhances the practical utility of topological indices in advanced material science.

The investigation of adsorption properties of dopamine has aroused significant attention in search for the design of effective biosensors. In this work, arsenene-based biosensors functionalized with Ag atoms are modeled and optimized using DFT calculations. The adsorption and surface reactivity of dopamine molecule can be enhanced over the Ag-functionalized arsenene nanostructures compared with the pristine systems. Charge density difference plots and total charge distribution analysis indicate the significant accumulation of charge densities over the adsorbed Ag atom and dopamine molecule. Compared with pure arsenene, surface modification by Ag adatom enhances the reactivity of arsenene, which is very conducive to biosensing of dopamine by arsenene surface. Moreover, in the PDOS analysis, there are great peak overlaps between Ag–O and Ag–N atoms, confirming the formation of chemical bonds between the Ag and O or N atoms. Our results indicate the substantial efficiency of Ag-functionalized arsenene nanosheets for sensing dopamine molecules.

Studies on copper nanoparticles (CuNPs) synthesis and its applications have been published on the basis of using different methods and reactants to minimize difficulties related to the experiments. This work mainly focuses on the synthesis of size- and shape-controlled copper nanoparticles by using nontoxic chemicals, a simple and cost-effective method, and its application. For that purpose, polyvinyl alcohol (PVA) solutions of different concentrations had been prepared to control the shapes and sizes of synthesized CuNPs produced by the reduction method using L-ascorbic acid at optimized conditions. Unlike others, instead of PVA film or gel, here standard PVA aqueous solutions were used. The different natures of the particles synthesized at different concentrations of PVA were examined successfully. It had been revealed that high concentration of PVA helps to stabilize the CuNPs by forming a stable cage-like structure. Polycrystalline, pentagonal, cylindrical, and spherical CuNPs of average size (11 nm) were synthesized by controlling the concentration of PVA solution. Lone L-ascorbic acid is unable to do that. This is the novelty of this work. The data obtained from UV–vis spectroscopy, DLS, TEM, XRD and fluorescence analysis facilitates establishing the fact. Additionally, it has also been observed that the special sized and shaped CuNPs are very effective in methyl orange (MO) dye degradation catalysis.