New Journal of Chemistry最新文献

The rational design of nanostructures with a controlled morphology is a crucial strategy for enhancing photocatalytic performance. A unique tremella-flake-like Co₃O₄-P nanostructure with a high specific surface area of 210.8 m² g⁻¹ was successfully synthesized via a facile calcination method. This material demonstrated exceptional activity in peroxymonosulfate (PMS)-activated degradation of rhodamine B (RhB) under visible light, achieving 99.6% removal within 1 min with a first-order rate constant of 5.4440 min⁻¹ and a normalized rate constant of 0.0258 g min⁻¹ m⁻². In contrast, commercial Co₃O₄-M showed only 1.4% degradation under identical conditions with the corresponding constants of 0.0406 min⁻¹ and 0.0035 g min⁻¹ m⁻². Enhanced activity of Co₃O₄-P originates not only from its high surface area but also from its distinctive microporous tremella-flake-like architecture which promotes charge carrier separation, prolongs its lifetime, and offers abundant active sites for PMS activation. This work provides valuable insights for designing high-performance catalysts through morphology engineering for environmental remediation.

The work described in this comprehensive study is based on valorising essential oils from citrus originated from Réunion Island, ortanic tangor, using Mukaiyama-type aerobic oxidation of terpenes, in particular limonene. This innovative work combines extraction, fractionation and catalytic oxidation to transform an agricultural residue into valuable compounds, while respecting the principles of green chemistry. The research highlights the use of metal salophen complexes based on cheap and abundant transition metals to achieve mild epoxidation at room temperature. In addition, a theoretical study using DFT provided a better understanding of the mechanism of this reaction for the best catalyst (molybdenum containing), suggesting that the activator could be a molybdenum oxo-cis-{Mo^VIO₂} species resulting from the evolution of the initial catalyst.

This work investigates the electrochemical behavior of ammonium manganese phosphate electrodes synthesized via a microwave method using two different precursors, MnSO₄ and Mn(CH₃COO)₂, for supercapacitor applications. From the Tauc plot, the NH₄MnPO₄–MnSO₄ and NH₄MnPO₄–Mn(CH₃COO)₂ band gaps were estimated to be 3.11 eV and 3.00 eV, respectively. SEM analysis revealed that the Mn(CH₃COO)₂-derived electrode forms sheet-like structures with higher surface area and porosity, promoting efficient ion diffusion and electron transport, which leads to superior electrochemical nature. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) studies demonstrated combined electric double-layer and pseudocapacitive behavior. NH₄VO₃, as a redox additive in 2 M H₂SO₄ electrolyte, enhanced reversible vanadium redox reactions, increasing the specific capacity by 54.4% and improving the energy density, rate capability, and long-term cycle stability. Full-cell tests with the NH₄MnPO₄–Mn(CH₃COO)₂//AC device showed excellent performance, retaining 99.4% capacity after 5000 cycles and highlighting the promising potential of ammonium manganese phosphate-based electrodes with redox-active electrolytes for supercapacitor applications.

The fascinating photochemistry of uranium and its increasing role in various technological applications have sparked renewed interest in exploring uranium-doped materials. In this study, we present the first detailed photophysical spectroscopy investigation of uranium-doped K₂MgGeO₄ (KMGO:U) phosphors, a promising material for optoelectronic and radiation detection applications. Our experimental results, which are well-supported by density functional theory (DFT)-calculated defect formation energy and density of states, provide crucial insights into the behavior of uranium in this matrix. X-ray absorption near-edge spectroscopy (XANES) confirmed the oxidation state of uranium as +6, while extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that uranium stabilizes as the uranyl ion (UO₂²⁺). DFT calculations further suggested that uranium substitution at the Ge⁴⁺ site is the most energetically favorable. Time-resolved photoluminescence measurements showed a distinct emission band around 530 nm, characteristic of the uranyl ion, and the excited-state lifetime demonstrated multiple decay channels, likely due to defects formed during aliovalent substitution of U⁶⁺ at the Ge⁴⁺ site. X-ray excited radioluminescence (RL) depicted a green band located at 530 nm typical of hexavalent uranium ion emission, further highlighting the ability of KMGO:U to convert energetic X-ray photons into visible light and its potential as an X-ray phosphor. These findings not only enhance our understanding of uranium's behavior in phosphor matrices but also open up exciting possibilities for their application in advanced technologies, including radiation sensing and imaging.

The application of ammonium polyphosphate (APP) as an additive flame retardant to epoxy resin (EP) flame retardants is common; however, APP poorly disperses and easily agglomerates in EP. For solving this problem, in this work, three kinds of ZnAl-layered double hydroxides (ZnAl-LDH1, ZnAl-LDH2 and ZnAl-LDH3) were successfully prepared using sodium hydroxide, urea and triethanolamine as different alkali sources, respectively, strengthening the flame retardant performance of EP with APP. Results showed that compared with pure-EP, the heat release peak and the smoke production rate peak decreased by 58.2% and 44.2% after the addition of APP (5 wt%) and ZnAl-LDH3 (5 wt%), respectively, which was prepared with triethanolamine as the alkali source. The incorporation of ZnAl-LDH3 promoted the dispersion of APP and increased the relative content of carbon elements during this process, as evidenced by SEM and XPS analyses. The metal oxides were uniformly distributed on the surface of the carbon layer after combustion. The residual carbon content of ZnAl-LDH3 was smaller than that of ZnAl-LDH1-APP-EP and ZnAl-LDH2-APP-EP, as observed in the Raman pattern. The heat release profile of APP-EP was better than that of ZnAl-LDH3-APP-EP; however, the tensile property and elongation at break of ZnAl-LDH3-APP-EP were better than those of APP-EP. A possible flame retardancy mechanism was proposed, according to which the C element introduced during the synthesis of LDHs promoted the cross-linking of EP and APP to form a denser carbon layer in the composite. Based on the above-mentioned results, triethanolamine shows potential as a source of both alkali and carbon in the preparation of LDHs. ZnAl-LDH3-APP-EP with good flame retardancy and mechanical properties could be employed as an efficient flame retardant material.

A superhydrophobic sponge (GO-g-PBA/APTES/MS) was fabricated through a facile and cost-effective dipping method. The as-prepared GO-g-PBA/APTES/MS adsorbed a broad variety of oils and organic solvents and exhibited high oil adsorption capacity (67.4–163.3 g g⁻¹). The GO-g-PBA/APTES/MS could be utilized as an efficient filter for continuous oil/water separation with the assistance of a peristaltic pump. Meanwhile, this superhydrophobic sponge could be easily recovered by simple squeezing and reused for at least 70 cycles, maintaining a high adsorption capacity. Furthermore, GO-g-PBA/APTES/MS displayed superior stability in corrosive liquids such as acidic, alkaline, and salty environments. These results provided a useful avenue for utilization of the GO-g-PBA/APTES/MS, demonstrating the potential for applications in oil/water separation and oil spill collection.

The reactions of β-caryophyllene with sulfonamides in acetonitrile in the presence of N-bromo- and N-iodosuccinimide have been studied. With NBS, only 3-amidino-6-bromo-1,1,7-trimethyldecahydro-3a,7-methanocyclopenta[8]annulenes have been isolated. With NIS, some sulfonamides afford their isomeric iodine analogues, 1-amidino-9-iodo-4,4,8-trimethyltricyclo[6.3.1.0^2,5]dodecanes, also as single products, whereas the other reagents give mixtures of both types of products. The yields vary from good to excellent, and the structure of five products was proved by X-ray analysis. The proposed mechanism involves halogenation of the endocyclic CC bond, subsequent intramolecular cyclization and either solvent interception by the formed carbocation or, prior to interception, four- to five-membered ring expansion. The experimentally observed stereo- and regioselectivity of the reaction is explained.

To be safely and effectively applied in the medical field, microencapsulated phase change materials must be multifunctional with sufficient mechanical strength. In this work, a series of n-octadecane@chitosan-graft-poly(methyl methacrylate) microcapsules were designed and fabricated by using a chitosan-grafting technique to enhance the mechanical strength and antibacterial activity. The optimal microcapsules exhibited a typical core–shell structure, particle sizes below 5 µm, a large heat storage capacity (ΔH_m = 195.69 J g⁻¹) and a high encapsulation efficiency (80.47%). Furthermore, the microcapsules demonstrated excellent pressure resistance (∼3.22 MPa), high thermal stability (∼280 °C) and outstanding cycling thermal stability (with 96.53% of ΔH_m retained after 100 cycles). Simultaneously, two types of medical applications were simulated, and the results demonstrated that the as-prepared P1-30 microcapsules performed outstandingly as a thermal manager for assisting medical treatments. Additionally, a trade-off model was constructed to analyze the relationship between encapsulation efficiency and yield, indicating the high effectiveness of our synthesis method in the microemulsion process. In summary, this article paves the way for broader applications of microencapsulated phase change materials in the medical field.

Perovskite solar cells (PSCs) are a promising green energy technology, although further improvements in efficiency and operational stability are still required. In recent years, carbazole-based self-assembled monolayer (SAM) hole-transport materials (HTMs) have been widely employed as interfacial modifiers in PSCs, effectively reducing the defect density at the perovskite/HTM interface and thereby enhancing device performance. However, significant challenges remain in elucidating the origin of the enhanced hole mobility in these HTMs and its possible correlation with perovskite interfacial properties. In this work, a series of new SAM-type HTMs (BM1–BM7) were designed using carbazole as the core building unit, followed by a comprehensive theoretical investigation. Their optoelectronic properties, as well as the interfacial characteristics of perovskite/SAM heterojunctions, were evaluated using density functional theory (DFT) and compared with those of the widely adopted HTM, (4-(3,6-dimethyl-9H-carbazol-9-yl) butyl) phosphonic acid (Me-4PACz). The scope of the study covers ground-state geometries, crystal packing, charge-transport properties, UV-Vis absorption and fluorescence emission spectra, and interfacial interaction analyses of HTM/perovskite and HTM/ITO systems. Notably, a high hole mobility of up to 2.79 cm² V⁻¹ s⁻¹ was achieved. All molecules, except BM4, exhibit favorable energy-level alignment with the perovskite absorber. Molecules possessing asymmetric π-extended structures show particularly strong adsorption at the perovskite interface. Overall, the results demonstrate that rational modulation of the conjugation degree and anchoring groups can substantially enhance charge-transport characteristics and interfacial performance, offering valuable insights for the development of high-performance HTMs.

The conversion of lignin to aromatic compounds constitutes one of the core issues in the utilization of biomass resources. In this study, a metal-free solid acid as a catalyst induces the C–C/C–O bond cleavage of lignin to obtain high-yield monocyclic aromatic compounds, which have the potential for resource conversion. Among them, 2-phenoxy-1-phenylethanol was used as a model compound to explore the possible mechanism of the reaction.