Chemistry

The thermodynamic properties of di-2-ethylhexylphosphoric acid (D2EHPA) in organic solvents are critical for optimizing metal extraction processes in hydrometallurgy, necessitating precise determination of activity coefficients in binary systems such as D2EHPA–n-hexane. This study was devoted to the determination of n-hexane’s concentrations in the vapor phase over D2EHPA solutions at 293.0 K using gas chromatography (GC) and isopiestic (IP) methods. Comparison with literature data confirmed the superior reliability of GC measurements at low n-hexane concentrations. The experimentally determined activity coefficients of hexane, obtained via GC, served as the initial input parameters for UNIFAC modeling. The optimized interaction parameters were 1144 ± 25 (CH₂-HPO₄) and 228 ± 50 (HPO₄-CH₂), with the infinite dilution activity coefficient for D2EHPA ${\gamma }_{\infty }=22.1$. These results experimentally clarify the non-ideal behavior of D2EHPA–n-hexane mixtures, establishing a validated thermodynamic modeling framework for organophosphorus extractant systems. This work establishes a fundamental basis for investigating ternary systems, such as D2EHPA–aliphatic solvent–aromatic solvent and D2EHPA–metal complex–solvent systems, paving the way for enhanced liquid–liquid extraction efficiency. Full article

Activated carbons were obtained from three types of raw materials from the canning industry: peach, plum, and olive stones. The chemical composition and texture of the precursors and the physicochemical properties of the obtained carbons were analyzed. It was found that under the same conditions of preparation, the properties of the raw materials significantly affect the parameters of the activated carbons. The obtained carbons were oxidized with 12% nitric acid to form a larger amount of acidic oxygen-containing groups on their surface. The porous texture, the size, and the chemical nature of the surface of the activated carbons were analyzed. The adsorption capacity of the obtained activated carbons towards chlorhexidine gluconate contained in mouthwash was determined. It was found that the three carbons have a significant adsorption capacity towards chlorhexidine gluconate: 189.1 mg/g for carbon from peach stones, 189.1 mg/g for carbon from plum stones, and 156.7 mg/g for carbon from olive stones, respectively. It has been determined that the adsorption of chlorhexidine gluconate on the surface of the obtained activated carbons obeys the Langmuir model. It has been established that the adsorption capacity of the obtained activated carbons is influenced by their porous texture, size, and chemical nature of the surface. Full article

Silver nanoclusters that are confined inside zeolites can give off intensive tunable emission across the visible region under UV excitation. In this research, a series of silver nanoclusters loaded with R-FAU/Ag (R = Li, Na, K) zeolites were synthesized and then applied as phosphors for LEDs. The XRD and SEM measurements showed the R-FAU/Ag (R = Li, Na, K) zeolites have high crystallinity and a size distribution of 0.7–1.25 μm. Under excitations of 310–330 nm ultraviolet radiation, Li-FAU/Ag, Na-FAU/Ag, and K-FAU/Ag exhibit monotonically declining emission intensities and red-shifted emissions with peak wavelengths of 520, 527, and 535 nm, respectively. By using silicone-based epoxy resin as the packaging material, a series of LEDs were fabricated by mixing R-FAU/Ag (R = Li, Na, K) phosphors. It is indicated that the Li-FAU/Ag-LED shows the strongest intensity of 94.9 mcd, much higher than that of the LEDs made from Na-FAU/Ag (63.7 mcd) and K-FAU/Ag (74.2 mcd) phosphors. Additionally, the chromaticity coordinate of the Li-FAU/Ag-LED is located at (0.2651, 0.4073) and has a high color temperature of 7873 K. Thermal test data showed that upon heating to 440 K, the intensities of R-FAU/Ag (R = Li, Na, K) LEDs decreased to 81%, 79%, and 75% of their initial intensities measured at 280 K, respectively. This research proposes a method for regulating the luminescent properties of silver nanoclusters in FAU zeolite by modifying the extra-framework cations and demonstrates excellent performance in LED products. Full article

Metal-free C(sp³)–S bond cleavage of thioethers was achieved using NCS as a critical additive. A wide range of arylmethyl thioethers were successfully transformed into aryl aldehydes with satisfactory yields in chloroform. Meanwhile, employing fluorobenzene as the solvent enables the selective formation of dithioacetals from arylmethyl thioethers, achieving moderate to good yields. Notably, dithioacetals were first prepared through a metal-free C(sp³)–S bond cleavage and subsequent thioacetalization process. Furthermore, these simple and efficient approaches also provide complementary strategies for accessing important aryl aldehydes and dithioacetals. Full article

The mesocarp, a by-product of coconut production, consists of a fibrous outer layer and a medullary tissue. These fibers can be utilized as an alternative source for producing activated carbon (AC). This study presents a method for producing activated carbon from coconut mesocarp fibers (CMFs) using a phosphoric acid (H₃PO₄) solution as the activating agent. The chemical activation process involves two stages: (1) carbonization of the CMFs, and (2) activation with H₃PO₄ at elevated temperatures. AC was characterized by its structural, thermal, surface morphological, and elemental properties. The resulting AC developed a lamellar structure with a porous network. Notably, the AC treated with a 60% v/v H₃PO₄ solution demonstrated a BET adsorption surface area of 1508 m²/g, a total pore volume of 0.871 cm³/g, and an average pore diameter of 2.20 nm. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of aromatic rings in the AC, while thermogravimetric analysis showed that the AC decomposed at 428 °C, compared to 418 °C for the non-activated carbon. Elemental analysis revealed a 9.04% increase in carbon content in the AC. Producing activated carbon from coconut mesocarp fibers offers a cost-effective method to generate high-surface-area activated carbon from agro-industrial waste. Full article

This work successfully prepared the Co₃O₄ NPs via simple galvanostatic deposition followed by annealing at 400 and 800 °C for two hours. The galvanostatic deposition was carried out from a modified Watts bath. We used Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to examine the oxide’s characterization properties. The nature of the oxide formed was strongly dependent on the annealing temperature. The powder formed at room temperature (25 °C) is a mixture of Co(OH)₂ and metallic Co. However, at 400 and 800 °C, and according to the XRD patterns, the powder consists of the Co₃O₄ phase and a slight quantity of Co(OH)₂ phase. The average particle size measured by TEM ranged from 14.85 nm at room temperature to 90.19 nm at 800 °C. Moreover, the study examined how the operating deposition parameters affected the galvanostatic deposition process. Furthermore, these baths provide NPs, that demonstrate antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria as well as antifungal activity against Aspergillus niger. Full article

Urban solid waste (USW) is a promising alternative source of valuable chemical compounds. It is considered an adsorbent material due to its chemical structure, porosity and electronic charge available to form chemical bonds and can be recovered or transformed for use in bioprocesses and industrial applications. This is the case with cigarette butts (CBs), which consist of thousands of substances that can be chemically converted for various purposes. This work showed high efficiency in the production of cellulose mass from the recycling of CBs, a patented technology in operation at the company Poiato Recicla—SP. The lignin-like solid (LLS)—a material obtained from the recycling of cigarette butts (CBs) by catalytic transfer hydrogenation (CTH), under non-rigorous conditions—showed high efficiency in its conversion into molecules of great interest. In the bio-oil obtained, characterized by analyses such as GCMS and RMN 2D HSQC, a mixture of predominantly hydrocarbons (many of them with cyclic and/or branched chains) was identified in almost all the experiments. This method demonstrates the potential of the TCH process for SSLs and completes the recycling chain designed for CBs, promoting their complete conversion into chemical compounds of greater interest. Full article

Mn(III)– and Co(III)–salen complexes (Mn-1 and Co-2) have been synthesized by a simple one-pot procedure through oxidation of Mn(II) and Co(II) precursors in air. X-ray structural analysis reveals that both complexes adopt similar coordination modes, including a typical square planar metal/salen coordination sphere, which is further occupied by two axial ligands, i.e., an acetate anion and a water molecule. Despite their structural similarity, they are not isomorphous given their distinct cell parameters. In the solid-state structures, both complexes exist as hydrogen-bonded dimers through hydrogen bonding interactions between the axially coordinating water molecules and outer O₄ cavity from another molecule of the complex. The reductive activity of both complexes has been explored. While the reaction of Mn-1 with potassium triethylborohydride was unsuccessful, leading to a complicated mixture, the use of Co-2 furnished the formation of a novel product (CoK-3) that was isolated as red crystals in reasonable yield. CoK-3 was characterized as a heterometallic dimer involving the coordination of a K⁺ ion within the O₄ cavity of a semi-hydrogenated salen/cobalt complex while the cobalt center has been reduced from Co(III) to Co(II). In addition, an attempt at reducing Co-2 with pinacolborane resulted in the isolation of crystals of Co-4, whose structure was determined as a simple square planar Co^II–salen complex. Finally, three complexes (Mn-1, Co-2 and CoK-3) have been investigated for their cytotoxic activities against two human breast cancer cell lines (MCF-7 and MDA-MB 468) and a normal breast epitheliel cell line (MCF-10A), with cisplatin used as a reference in order to discover potential drug candidates that may compete with cisplatin. The results reveal that Co-2 can be a promising drug candidate, specifically for the MCF-7 cancer cells, with minimal damage to healthy cells. Full article

The preparation of stable dispersions of MoS₂ by ultrasonic aqueous and/or organic media containing amphiphilic molecules is an attractive and widely applicable method to form MoS₂ fine particles while suppressing its aggregation. In this study, we developed a series of polymers with pendant sulfide moieties as a new dispersant, under the hypothesis that it would interact with sulfur atoms on MoS₂ surfaces. First, we designed a sulfide group-substituted methacrylate derivative (ESMA) with the hypothesis that it would interact with the MoS₂ surface through sulfur-sulfur interactions. Then, we synthesized well-defined polymers with pendant sulfide groups by living radical polymerization (ATRP). Next, 0.5 wt% MoS₂ was added to a DMSO solution containing 1 wt% of the obtained polymer (polyESMA), and the mixture was treated with a bath-type ultrasonicator for 3 h to obtain a MoS₂ dispersion. We found that stable dispersions of MoS₂ in a fine particle state, although not in the form of single-layer or few-layer nanosheets, could be readily formed in DMSO using polyESMA as a polymeric dispersant. Furthermore, we synthesized polymeric dispersants with different molecular weights and investigated the relationship between the structure of the dispersant and the dispersion stability. Full article

A novel polyhedron-based anionic Er-MOF with three types of cages and abundant open metal sites (OMSs) and Lewis base sites (LBSs) has been successfully synthesized. The inorganic secondary unit possesses a rarely reported six-connected three-nucleated rare-earth cluster, and the overall framework shows a new (3,3,6)-connected topology. The Er-MOF has good fluorescence selectivity and anti-interference performance with Fe³⁺ and Cu²⁺. In addition, benefiting from the anionic framework, nanoscale cavity and small window size of the Er-MOF, the composite RhB@Er-MOF has been synthesized by in situ encapsulation of the cationic dye Rhodamine B (RhB). It can provide dual-emitting fluorescence that facilitates self-calibration in sensing. The RhB@Er-MOF has higher accuracy than the Er-MOF with regard to the fluorescence-selective and anti-interference performance of Fe³⁺ and quenching coefficient K_sv values of 1.97 × 10⁴ M⁻¹, which are attributed to its self-calibration function that can eliminate environmental interference. The fluorescence quenching mechanism was explained by our experiments and density functional theory (DFT) calculations. Furthermore, RhB@Er-MOF can achieve the visual and rapid selective detection of Fe³⁺ by a smartphone RGB color analysis application, resulting in the dual-signal output performance of the material. Full article

Lysosomes are widely present in eukaryotic cells and play an extremely important role in cell growth and development, and their dysfunction is closely related to a variety of diseases. The development of a precise lysosomal targeting strategies is of great significance for the detection of lysosomal physiological functions and the diagnosis and treatment of related diseases. Morpholino ring modification has become a commonly used lysosomal targeting strategy, but its effects have not been systematically evaluated. This review summarizes the effects of morpholine rings in fluorescent probes in recent years. The results show that morpholine rings as lysosomal targeting groups have excellent structural adaptability, but their localization effect is influenced by the log p value and charge of the overall molecule, and this effect has structural differences. In addition, since the morpholino ring is essentially an acidic microenvironmental targeting moiety, it carries the risk of off-targeting to other acidic sites. Full article

Cobalt–zeolite composite catalysts (Co–zeolite) and their heterogeneous catalytic systems have garnered significant research attention owing to their superior catalytic activity and cost-effectiveness. The speciation of cobalt within these catalysts—either through impregnation onto the zeolite framework or structural incorporation within the aluminosilicate matrix—is critically governed by the employed synthesis methodology, which subsequently dictates their distinct catalytic advantages in targeted reaction systems. Compared to homogeneous catalytic systems, heterogeneous Co–zeolite configurations demonstrate enhanced structural integrity that effectively mitigates cobalt leaching, thereby improving catalyst recyclability while minimizing environmental contamination. This review systematically examines recent advancements in Co–zeolite fabrication techniques and their catalytic performance across diverse applications, including Fischer–Tropsch synthesis, nitrogen oxide abatement, hydrogenation processes, and oxidative transformations. Particular emphasis is placed on elucidating the metal-framework interactions, with analysis of synergistic effects arising from multi-valent cobalt speciation and bimetallic cooperativity between cobalt and secondary transition metals. This work critically evaluates current challenges in Co–zeolite catalyst design. Finally, we propose future research directions focusing on a precise identification of active species and mechanistic elucidation, innovative synthesis strategies for cobalt speciation control, machine learning-guided catalyst optimization, and the advancement of eco-friendly catalysts. Full article

This review focuses on research on machine learning-enabled two-dimensional (2D) materials, exploring the progress and prospects of this interdisciplinary field. At a fundamental level, machine learning algorithms incorporate imaging systems to build highly accurate viewing frameworks for material analysis. Two-dimensional materials have a rich set of optical properties, including light absorption and emission, anisotropy, photoluminescence, and nonlinear optical effects, which machine learning can accurately understand through image characterization, spectral fusion, and quantitative analysis. Meanwhile, the preparation process and post-processing are key aspects in the growth regulation of 2D materials, and machine learning helps optimize the experiments by analyzing the growth kinetics for fine control. Related research has spawned many academic achievements, gradually penetrating electronics, energy, and other industrial applications. The innovation of imaging technology and the deepening of multidisciplinary integration are expected to unlock more emerging applications and expand the application boundaries of 2D materials. Full article

This review focuses on photocyclization reactions involving alkenes and arenes. Photochemistry opens up synthetic opportunities difficult for thermal methods, using light as a versatile tool to convert stable ground-state molecules into their reactive excited counterparts. This difference can be particularly striking for aromatic molecules, which, according to Baird’s rule, transform from highly stable entities into their antiaromatic “evil twins”. We highlight classical reactions, such as the photocyclization of stilbenes, to show how alkenes and aromatic rings can undergo intramolecular cyclizations to form complex structures. When possible, we explain how antiaromaticity develops in excited states and how this can expand synthetic possibilities. The review also examines how factors such as oxidants, substituents, and reaction conditions influence product selectivity, providing useful insights for improving reaction outcomes and demonstrating how photochemical methods can drive the development of new synthetic strategies. Full article

MIL-101(Cr), a widely studied chromium-based metal–organic framework material consisting of chromium metal ions and terephthalic acid ligands, has attracted much attention due to its ultra-high specific surface area, large pore size, and excellent thermal, chemical, and aqueous stability. The outstanding properties and abundant unsaturated Lewis acid sites of this material have shown promising applications in aqueous phase adsorption, gas storage, separation, catalysis, drug delivery, and sensing. In this paper, we systematically review the synthesis technology and performance optimization strategy of MIL-101(Cr), discuss the advantages and limitations of various synthesis methods, such as traditional hydrothermal method, microwave-assisted hydrothermal method, template method, and solvent-thermal method, and summarize and analyze the optimization strategy of MIL-101 from the aspects of physical modification and chemical modification. In addition, this paper summarizes the latest application progress of MIL-101(Cr) in gas adsorption and separation, wastewater purification, pollutant removal, catalysis, and pharmaceutical delivery, and points out the current challenges and future development directions, to provide guidance and inspiration for the industrial application of MIL-101(Cr) and the development of new materials. Full article

Phlorotannins, bioactive compounds isolated from brown seaweeds, have garnered significant attention in recent years for their wide-ranging therapeutic properties, particularly their anti-inflammatory effects. Recent studies have identified phlorotannins as potent inhibitors of inflammatory pathways such as NF-κB, MAPK, JAK/STAT3, and NLRP3. Specifically, phlorotannins derived from seaweeds like Ecklonia cava, Ishige okamurae, and Sargassum horneri have been shown to inhibit the gene and protein expression of pro-inflammatory cytokines and other inflammatory mediators in both in vivo and in vitro conditions. Despite these promising findings, no commercial drugs derived from seaweed phlorotannins have yet been developed to treat inflammatory diseases, and reports of clinical trials remain rare, even in the context of functional food applications for chronic inflammatory conditions. To address this knowledge gap, the authors reviewed peer-reviewed research articles published in 2020 or later, focusing on the anti-inflammatory potential of phlorotannins. The insights provided in this review are expected to be valuable for industries such as functional food research groups and others involved in developing anti-inflammatory therapeutics. Full article

Direct Z-scheme heterojunctions are known for their unique carrier mobility mechanism, which significantly improves photocatalytic water splitting efficiency. In this study, we use first-principles simulations to determine the stability, electrical, and photocatalytic properties of a SnC/SnS₂ heterojunction. Analyses of the projected energy band and state density demonstrate that the SnC/SnS₂ heterojunction exhibits an indirect band gap of 0.80 eV and a type-II band alignment. Analysis of its work function shows that the SnC/SnS₂ heterojunction has a built-in electric field pointing from the SnC monolayer to the SnS₂ monolayer. The band edge position and the differential charge density indicate that the SnC/SnS₂ heterostructure exhibits a Z-scheme photocatalytic mechanism. Furthermore, the SnC/SnS₂ heterojunction exhibits excellent visible-light absorption and high solar-to-hydrogen efficiency of 32.8%. It is found that the band gap and light absorption of the heterojunction can be effectively tuned by biaxial strain. These results demonstrate that the fabricated SnC/SnS₂ heterojunction has significant photocatalysis potential. Full article

Zinc-halogen batteries are usually based on two-electron transfer reactions from X⁻ to X₂. However, the halogen is capable of being further oxidized to higher valence states, thereby achieving the higher capacity of zinc- halogen batteries. Here, a six-electron reaction based on I⁻/I⁺ and Br⁻/Br⁰ is activated successfully by introducing KI into the electrolyte. ZIF-8-derived porous carbon (ZPC), serving as the host of halogen, effectively suppresses polybromide/polyiodide shuttle owing to the chemisorption/physical adsorption. Additionally, the adsorption of I⁻ on the surface of the zinc anode effectively inhibits the growth of dendrites and the formation of by-products. Consequently, zinc-bromine batteries exhibit outstanding electrochemical performance, including a specific capacity of 345 mAh g⁻¹ at 1 A g⁻¹ and an excellent capacity retention of 80% after 3000 cycles at 2 A g⁻¹. This strategy provides a novel way for enhancing the electrochemical performance of zinc-halogen batteries. Full article

In this study, a statistical analysis of results reported in the literature was conducted through a 2ⁿ experimental design on the synthesis of bifunctional catalysts used in the production of lighter fuels, aiming for optimization while considering factors such as support (bentonite and vermiculite), acidity modifier (zirconium and cerium), metal (tungsten and molybdenum), metal content (5% and 10%), promoter (nickel and cobalt), and heteropolyacids (tungstophosphoric acid and molybdophosphoric acid), identifying their influence on textural properties and catalytic performance. Regarding the textural properties, vermiculite proved to be the most favorable support due to its high porosity. It was also established that the implemented metals impart positive characteristics to the catalysts due to their various properties; however, incorporating large amounts led to an adverse effect by clogging the pores. Catalytic performance was analyzed in isomerization and cracking reactions, which were enhanced by the use of cerium due to the presence of Brønsted acid sites and molybdenum for its stability. In this way, the statistical analysis conducted in this study was crucial for identifying the influence of key factors on the textural properties and catalytic performance of bifunctional catalysts. Using a 2ⁿ experimental design allowed for a systematic evaluation of variables reported in the literature, such as support, acidity modifiers, metals, metal content, promoters, and heteropolyacids. Full article