Stimulus-responsive metal-organic frameworks (MOFs) are a subclass of MOFs that undergo physicochemical changes in response to external stimuli. The large surface area, tunable properties, and high porosity of MOFs and their dynamic nature of stimulus-responsiveness, making them highly effective for sensing applications. The luminescence properties of MOF-based sensors enable optical detection, making them cost-effective compared with conventional sensing techniques. MOFs can response to various stimuli; however, the practical application of these stimulus-responsive MOFs is limited by challenges such as poor processability and stability, requiring further advancements to enhance their real-world viability. Recently, the integration of stimulus-responsive MOFs into hydrogels has been extensively explored to improve their performance as sensors. This review highlights the utilization of stimulus-responsive MOF-hydrogel composites as sensors. The types of stimuli, preparation methods, and the distinct roles of both MOF and hydrogel components are discussed. The applications covered include biosensing, environmental remediation, and agricultural food safety monitoring, with target analytes spanning across heavy metals, toxic anions, volatile organic compounds, pesticides, biomolecules, and mycotoxins. Furthermore, the challenges and future prospects of stimulus-responsive MOF-hydrogel composites are evaluated, with rational design strategies proposed to guide future development.
We report the synthesis of acetonedisulfonic acid ([(HOSO2CH2)2CO], ADSA) by slow reaction of acetone and oleum (65% SO3) and subsequent removal of H2O. The new acid was used to prepare potassium acetonedisulfonate, K2[ADS] (ADS = [(OSO2CH2)2CO]2-), as well as the rubidium and the pyridinium salts, Rb2[ADS] and [PyH]3[ADS][HSO4], respectively. Furthermore, we present an alternative one-pot reaction yielding the ammonium salt [NH4]2[ADS], which we characterized spectroscopically. The latter was used for a subsequent salt metathesis reaction for the preparation of the strontium and calcium salts. For the first time, all these compounds were structurally elucidated by single-crystal X-ray diffraction methods (SCXRD), revealing different conformers that the [ADS]2- anion may adopt. Deeper insights into the structural versatility of the new compounds were gained by quantum chemical calculations. These investigations led to the molecular electrostatic potential (MEP) surfaces of the acid, as well as of the [NH4]+ and the [C5H6N]+ salt, mapping the energetic landscape of the different species as a tool to predict the different reactivities. Subsequently, energetic and Bader's quantum theory of atoms in molecules (QTAIM) analyses were used to show the stabilization potential of the strong hydrogen bonds present in all of the three species and their influence on the intramolecular assemblies found in the solid state.
Over the last 15 years, our laboratory has explored peptidomimetics in diverse research areas, including AApeptide folding, structure-based design, combinatorial screening, and supramolecular chemistry. Through these efforts, we successfully introduced a new subclass of AApeptides known as sulfonyl-γ-AApeptides. In recent years, we took advantage of the synthetic scaffold and rationally designed and developed helices targeting a series of protein-protein interactions. This Perspective summarizes our recent advances in developing right-handed helical D-sulfonyl-γ-AApeptides, which closely resemble the secondary structure of canonical α-helices and represent a promising platform for α-helical mimicry.
Lithium-ion batteries are now widely used in consumer electronics and new energy vehicles. At present, commercial anode materials are mainly graphite; however, the relatively low theoretical specific capacity of graphite makes it difficult to meet the growing demand for high-energy-density storage. Silicon-based materials have abundant reserves and significant cost advantages, with a theoretical specific capacity of up to 4200 mAh g-1, roughly 10 times that of graphite, making them a highly promising next-generation anode replacement material. However, silicon undergoes nearly 300% volume expansion during lithium insertion and extraction, which easily causes particle pulverization and damage to the electrode's conductive network, ultimately leading to a severe decline in cycle life and capacity stability. Preparing Si/C composite systems can effectively address these issues. The carbon matrix can include traditional carbon precursors such as graphite and pitch, as well as novel carbon materials like graphene, MXene, and MOF-derived carbon. This paper systematically reviews mainstream Si/C composite preparation methods, including dry ball milling, spray drying, high-temperature pyrolysis, and chemical vapor deposition; analyzes the mechanisms by which each process regulates material microstructure and Si/C interface bonding; and summarizes effective strategies to enhance electrode electrochemical performance through process optimization.
This study explores the interaction of human serum albumin (HSA) with two flavonoids (FLs), baicalein and scutellarein, and in situ formed Cu(II)-FL complexes using fluorescence spectroscopy, molecular docking, and molecular dynamics simulations. Fluorescence quenching experiments show diminished fluorescence intensity indicating that all compounds effectively bind to HSA, with free scutellarein exhibiting slightly higher affinity. Cu(II) coordination reduces quenching efficiency; however, the binding processes remain thermodynamically favorable. UV-Vis spectroscopy confirmed well-defined ground-state HSA-flavonoid complexes with minor indications of subtle protein conformational adjustments. A novel composite scoring function integrating effective free energies and thermodynamic stability was used to compute theoretical free energies. The results are in agreement with experimental results, showing that all ligands preferentially bound in Sudlow site I, while baicalein also samples site III. Per-residue energy decomposition indicates that Cu(II) complexes are stabilized by electrostatic interactions further from the intrinsic fluorophore Trp214. Clustering analysis reveals distinct conformational landscapes, with baicalein favoring a few dominant states, whereas scutellarein adopts a more fragmented ensemble. Overall, HSA effectively accommodates both free and Cu(II)-complexed flavonoids, with metal coordination subtly modulating binding preferences and conformational dynamics.
Designing green and efficient methods for synthesizing anilines remains a key challenge in synthetic organic chemistry. Hydrogenation of nitro compounds is one of the most significant and widely employed method for producing functionalized anilines. Consequently, designing catalytic systems capable of hydrogenating nitroarenes under environmentally benign and mild reaction conditions remains a challenge. In this regard, a highly efficient CoAl catalyst has been designed for the hydrogenation of nitroarenes to corresponding amines. Various structural, compositional, and morphological characterizations were done to understand the catalyst's structural and surface properties. The as-synthesized catalyst exhibits excellent activity for the transfer hydrogenation of 1-chloro-4-nitrobenzene to 4-chloroaniline, achieving 98% yield at 60 °C within 1.5 h in ethanol. The developed protocol demonstrated excellent activity for wide range of substituted nitroarenes. Structure-activity relationships of CoAl show that basic sites play a crucial role in the transfer hydrogenation. Furthermore, mechanistic investigations reveal that transfer hydrogenation occurs predominantly via a hydroxylamine-mediated pathway. Moreover, the catalyst maintains good catalytic activity up to four consecutive cycles. This method eliminates the need for high-pressure H2, offering a safe strategy for aromatic amine synthesis. The work demonstrates the potential of earth-abundant, non-noble-metal-based heterogeneous catalysts for hydrogenation reactions under environmentally benign conditions.
InP/ZnSe/ZnS core/shell/shell quantum dots (CSS-QDs) have already demonstrated considerable research potential in photocatalytic hydrogen evolution. To boost the photocatalytic hydrogen evolution activity of CSS-QDs, this work evaluated the impacts of Ni and Pt cocatalysts on catalytic performance, alongside their chemical behaviors under reaction conditions. Compared with pristine CSS-QDs, Ni and Pt cocatalysts boosted the catalytic activity by ∼4.5-fold and ∼51.2-fold, respectively, with Pt delivering a breakthrough activity enhancement. Systematic experiments revealed that Ni remained predominantly in ionic form during the reaction, while Pt existed in the form of elemental and oxide nanoparticles anchored on the CSS-QDs surface. The stronger interfacial interaction and faster electron transfer between Pt and CSS-QDs accounted for the superior catalytic performance. This work further highlights the application potential of InP-based QDs in photocatalytic hydrogen evolution, and provides both experimental evidence and theoretical guidance for the design and optimization of high-efficiency cadmium-free photocatalytic hydrogen evolution systems.
The development of efficient and sustainable ceramic catalysts for biodiesel production has attracted considerable attention as a strategy to reduce fossil fuel dependence and environmental impacts. This review critically examines alkali- and alkaline earth metal oxide-modified silicate, aluminosilicate, and zeolitic ceramic materials as heterogeneous catalysts for transesterification and esterification of lipid feedstocks. Emphasis is placed on the relationships between catalyst structure, surface acidity/basicity, and catalytic performance. Incorporation of alkali (K+, Na+, Li+) and alkaline earth (Ca2+, Mg2+) metal ions into ceramic frameworks enhances active-site density, reactant adsorption, and reaction kinetics, enabling biodiesel yields exceeding 90%-99% under optimized conditions. The effects of framework topology, pore architecture, and surface area on mass transfer and catalyst accessibility are discussed, together with the roles of zeolites, clays, and mesoporous aluminosilicates in improving catalyst stability, reusability, and resistance to leaching. Current challenges, including catalyst deactivation, feedstock impurities, and scale-up limitations, are critically evaluated. Emerging strategies involving waste-derived ceramics, bifunctional catalysts, and process intensification are highlighted to guide the rational design of next-generation heterogeneous catalysts for sustainable biodiesel production.
Multimodal imaging can improve the detection of molecular and pathophysiological changes by combining complementary readouts within a single probe. Here we report the synthesis and characterization of a fluorinated BODIPY dye (F54-BODIPY) designed as dual fluorescence/19F-MRI imaging agent. The molecular design replaces the native BF2 unit with multibranched perfluoro-tert-butoxy chains appended at the boron atom via BO hexyloxy linkages, providing 54 magnetically equivalent 19F nuclei per molecule. Additionally, 2,6-dimethylphenyl groups are introduced at 2,6-positions of F54-BODIPY, and (E)-4-methylstyryl residues at the 3,5-positions extend emission into the far-red region of visible spectrum. This probe was structurally characterized by NMR spectroscopy, and its photophysical properties were evaluated by UV-Vis absorption, fluorescence spectroscopy, and fluorescence quantum yield (Φf) measurements. Subsequently F54-BODIPY was encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) for dispersion in aqueous media. Co-encapsulation of a second fluorinated phase, namely perfluoro-15-crown-5 ether (PFCE), significantly modified fluorescence properties and introduced a second 19F-NMR signal, yielding a bimodal nanosystem with dual 19F-NMR signals and red fluorescence emission for combined fluorescence/19F-MRI bioimaging.
The design of sustainable wastewater treatment strategies for recalcitrant pollutants, including per- and polyfluorinated alkyl substances (PFAS) and pesticides, remains a critical challenge. In this study, silver-zinc core-shell nanostructures (Ag@ZnNP), consisting of a zinc core and silver shell, were dispersed on TiO2 and investigated as photothermal materials for the degradation of perfluorooctanoic acid (PFOA) and fipronil. Ag@ZnNP nanoparticles (Ag@ZnNP) were synthesized via pulsed laser ablation in liquid of a zinc target in the presence of silver nitrate. By tuning silver nitrate concentration, materials with optical and photothermal properties comparable to pure silver nanoparticles were obtained while reducing the silver content. X-ray diffraction confirmed a crystalline silver shell and a zinc core, while atomic emission spectroscopy indicated a composition of 67% ± 4% Ag and 33% ± 4% Zn. The Ag@ZnNP/TiO2 composite exhibited PFOA degradation efficacy comparable to Ag/TiO2 via blue light-initiated photothermal sulfate radical formation, achieving 85% degradation after 7 h. The Ag@ZnNP/TiO2 composite achieved 88% fipronil removal within 1 h under blue light irradiation (455 mW cm-2) without sulfate radicals. These results demonstrate the potential of Ag@ZnNP/TiO2 as an efficient, lower-silver photothermal material for degrading persistent environmental contaminants.
Methylaluminoxane (MAO) is the most widely used cocatalyst in single-site olefin polymerization, yet its molecular structures have decisively resisted characterization. Computational chemistry has played an indispensable role throughout the characterization efforts, from the earliest cage-based structural proposals inspired by tert-butylaluminoxane analogs through systematic hydrolysis-based modeling to the identification of two-dimensional sheet structures as the thermodynamically preferred motif. This review traces that computational journey, with particular attention to the methodological advances and failures that shaped it. The discovery that widely used density functional theory methods for MAO carry systematic errors for four-coordinate aluminum-oxygen environments, and that vibrational entropy rather than electronic energy is the decisive thermodynamic quantity in the experimentally relevant size domain, fundamentally redirected the field. The resulting ovalene-based sheet model for the dominant [(AlOMe)16(AlMe3)6Me]- anion is simultaneously consistent with electrospray ionization mass spectrometry, solid-state NMR, X-ray crystallography, and synchrotron pair distribution function data, and yields catalyst activation barriers in reasonable agreement with experiment. The structural foundation now established for the dominant anionic component of fresh MAO opens a realistic path toward understanding the full complexity of the MAO mixture and toward rational design of next-generation aluminum-based cocatalysts.
In this study, a novel Ni-MoO3@MIL-101(Cr) composite catalyst was synthesized via a one-step hydrothermal method for the oxidative desulfurization (ODS) of dibenzothiophene (DBT). The catalyst combines the high specific surface area of MIL-101(Cr) with the redox properties of Ni-MoO3, providing an effective synergy between adsorption and catalytic oxidation. The incorporation of Ni as a promoter significantly enhances catalytic activity, enabling complete sulfur removal (∼100%) under mild conditions (50 °C) within 60 min. Structural characterizations (scanning electron microscopy, X-ray diffraction, and SAED) reveal that the catalyst retains its nanosheet-nanorod morphology and crystalline MoO3 phase after repeated use, with only a slight decrease in the crystallinity of the MIL-101(Cr) framework. Mechanistic analyses using X-ray photoelectron spectroscopy, Raman, and temperature-programmed reduction demonstrate that surface oxygen vacancies and Lewis acid sites promote ODS activity, while highly dispersed Ni-MoO3 species facilitate H2O2 activation and Mo6+/Mo5+ redox cycling, leading to efficient generation of reactive oxygen species. The catalyst also exhibits excellent stability, maintaining 98.7% DBT conversion after five cycles. These results demonstrate that the strong Ni-Mo synergistic effect and efficient oxygen activation make Ni-MoO3@MIL-101(Cr) a robust and highly efficient catalyst for deep fuel desulfurization.
Machine learning (ML) has been utilized in this study to screen optimal donor and acceptor counterparts of solar cell molecules based on the device efficiency. Almost 42 ML models are tested, among which random forest (RF) regression, light gradient boosting machine (LGBM), and Nu support vector regression (NuSVR) models appear to be the best models. The solar cell device performance defined by the device properties, i.e., photoconversion efficiency (PCE (%)), short-circuit current (Jsc (mA/cm2)), open-circuit voltage (Voc (V)), and donor and acceptor molecule's charge transfer (ΔN) are predicted using best ML model selected based on its high R2. Suitable resemblance of predicted and actual values is found for all those properties. Chemical reactivity parameters of donor and acceptor molecules have been utilized to screen the best donor and acceptor molecules based on their PCE (%) values. Synthetic accessibility assessment has also been considered as one of the parameters in the optimization process that signifies the ease of synthesis of the donor and acceptor molecules. This strategic ML framework is able to find the efficient donor and acceptor counterparts based on its chemical stability that directly influence solar cell performance, in short time and in an efficient way.
Electrochemical urea oxidation (UOR) enables energy-efficient hydrogen production coupled with wastewater remediation, representing a promising sustainable technology. Nanostructured cobalt-based catalysts have emerged as leading UOR candidates due to their tunable electronic structures, high intrinsic activity, and excellent stability. This review critically analyzes cobalt's mechanistic role in nickel oxyhydroxides, focusing on how Co doping modulates electronic structures, optimizes reaction pathways, and breaks the scaling relations limiting pure Ni catalysts. We summarize diverse nanoengineering strategies that synergistically enhance active site exposure, charge transfer kinetics and anti-deactivation performance. Key challenges (catalyst poisoning, sluggish multielectron kinetics, byproduct formation) and emerging solutions are discussed. Finally, we outline prospects for integrating advanced Co-based UOR catalysts into large-scale electrolysis systems to accelerate commercialization.
The global demand for lithium has driven the pursuit of efficient extraction from complex sources like salt lake brine and seawater. Conventional membranes face a "permeability-selectivity trade-off," especially under high salinity and competitive conditions. This review examines advances in lithium-selective membranes, from basic size-sieving and charge regulation to biomimetic channels using molecular recognition and asymmetric gating. Beyond these conventional approaches, we emphasize a pivotal and necessary paradigm shift in ion transport strategy to address the limitations of traditional "forward-flow" separation. Specifically, we highlight our recent research into the design of artificial cation-chloride cotransporters, which bypasses the constraints of salt-induced Debye screening by facilitating electroneutral ion pair migration, thereby enabling resilient lithium extraction from concentrated brines. Furthermore, we discuss the "reverse lithium extraction" paradigm, a strategic reassessment of separation strategy that prioritizes the selective retention of Li+ within the membrane matrix. By allowing competing cations to permeate freely while trapping the target species, this "reverse sieving" strategy effectively sidesteps the overwhelming competitive pressure characteristic of seawater mining. By analyzing the interplay between nanoconfinement chemistry and ion transport kinetics, this review provides a strategic roadmap for the development of the next generation of resilient separation materials for global lithium resource harvesting.
The structure-activity relationship between persulfate activation by carbon-based catalysts and organic compound oxidation is a key scientific issue. However, previous studies have paid insufficient attention to this topic. This article systematically elucidates this relationship and mechanism of action using modified carbon catalysts. Using selective oxidation of benzyl alcohol to benzaldehyde and lignin dimer depolymerisation as reaction models, nitrogen-doped graphene (NG-4) and CoFe2O4/g-C3N4 (30-CFO/BCN) composites were systematically characterised by XRD, XPS, EPR, and other techniques. In benzyl alcohol oxidation, NG-4 achieves 99.2% benzaldehyde selectivity via an electron-transfer-dominated non-radical pathway. Its performance is attributed to the synergistic interaction between pyridine nitrogen and ketone carbonyl, driving both radical and non-radical pathways. In lignin depolymerisation, 30-CFO/BCN composite catalyst activates persulfate to generate SO4•--dominated radicals, achieving complete dimer conversion with 70.8% veratraldehyde yield. This enhanced activity is closely related to the increased Co2+/Co3+ ratio and oxygen vacancy concentration. Furthermore, incorporating this catalyst into functional hydrogel systems expands its application potential in conductive materials and wastewater treatment. This study provides fundamental insights into the reaction mechanisms of persulfate-based catalytic systems and offers theoretical guidance for catalyst design in green synthesis and biomass resource utilisation.
Titanium alloys are basic materials used in implantology. Their properties can be modified in many ways, e.g., by morphological changes or covering with different bioactive molecules. Platinum(II) complexes are a significant group of anticancer drugs. In an organism, they undergo many chemical processes. A ligand substitution with the S‐donor ligands (glutathione (GSH), metallothioneins) is among the most important. This process can be applied to the modification of titanium alloys (Ti6Al4V) with platinum(II) complexes, e.g., [Pt 2 (6NNqui)Cl 4 ] (PtQ6). The paper presents a modification of the Ti6Al4V alloy with titania nanotubes and the studied complex, using the bridging ligand (3‐mercaptopropyl)triethoxysilane (MPTES). Moreover, a kinetic study on chloride substitution in the studied bimetallic cisplatin analogue (PtQ6) by L‐cysteine, an amino acid that is a part of GSH and metallothioneins, is also presented. It is a good way to get locally active implants in the targeted anticancer therapy. The produced material is characterized with spectral and microscopic methods, including XPS (X‐ray photoelectron spectroscopy). The mechanism of the substrate modification with platinum(II) complex is based on the substitution process. The nanomechanical properties of the modified and functionalized substrate are also tested in the indentation tests.
Photo‐assisted upcycling of nonbiodegradable plastic waste offers a sustainable route to mitigate plastic pollution, yet remains limited by low efficiency and poor product selectivity. Herein, we report a S‐scheme heterojunction photocatalyst composed of sulfur‐doped and sulfonic‐acid functionalized graphitic carbon nitride coupled with iron oxide (S‐g‐C 3 N 4 /Fe 2 O 3 ) for selective plastic upcycling under ambient conditions. The synthesized catalyst converts polyethylene, polystyrene, and polyethylene terephthalate into acetic acid under simulated sunlight, achieving up to 77% polyethylene conversion with a yield rate of 0.42 mmol g⋅cat −1 h −1 . Radical trapping experiments identify electrons and holes as the key reactive species. Combined Fourier transform infrared spectroscopy (FTIR), UV‐Visible (UV‐Vis) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and as chromatography analyses confirm CO 2 formation by photooxidation of polyethylene followed and subsequent reduction to acetate. Importantly, the photo upcycling of the commercial plastic products further validated the practicality of this approach for sustainable C 2 chemicals production.
