In marine environments, epoxy coatings suffer from the penetration of corrosive species through microstructural defects and interfacial discontinuities, causing a rapid degradation in barrier performance during service. Nano-oil can alleviate the aggregation and poor interfacial compatibility of conventional nano filler in epoxy. Here, we synthesized the SiO2 nano-oil by γ-Glycidoxypropyltrimethoxysilane functionalization and ring-opening grafting with bis(3-aminopropyl)-terminated polydimethylsiloxane and then incorporated it into epoxy coatings. SiO2-K@PDMS exhibited liquid-like characteristics such as shear-thinning behavior and low surface tension. Electrochemical impedance spectroscopy results showed that the 4 wt% SiO2-K@PDMS/EP system achieved an initial |Z| at 0.01 Hz of 1.73 × 1010 Ω·cm2, 436 times that of pure EP. After immersion in 3.5 wt% NaCl solution for 30 d, its |Z| at 0.01 Hz remained at 3.07 × 109 Ω·cm2, about 3.88 × 104 times that of pure EP. Scratched salt spray and fracture surface SEM results showed that SiO2-K@PDMS mitigated corrosion propagation at defect sites and reduced filler aggregation and interfacial voids, which is consistent with its superior long-term impedance retention. In addition, this filler increased the surface hydrophobicity of the coating and reduced the initial adhesion of E. coli. SiO2 nano-oil shows great potential for enhancing long-term protection performance of anticorrosion coatings.
MXene quantum dots (MXQDs), produced by downsizing two-dimensional MXenes into zero-dimensional nanostructures, have emerged as promising materials for next-generation supercapacitors owing to their quantum confinement, metallic conductivity, abundant surface terminations, and excellent dispersibility. This review summarizes recent advances in MXQDs with emphasis on the synthesis structure-property-performance relationship governing their electrochemical behavior. Various synthesis strategies, including hydrothermal, microwave-assisted, laser-induced, and acousto-microfluidic methods, are discussed in relation to their effects on size, crystallinity, morphology, and surface chemistry. Advanced characterization techniques, including XRD, Raman, FTIR, TEM/HRTEM, and AFM, are highlighted for elucidating crystal structure, defect states, and surface functional groups. The effects of quantum confinement, heteroatom doping, defect engineering, and surface terminations on charge-transfer kinetics, ion diffusion, and pseudocapacitive behavior are critically examined. Furthermore, recent developments in MXQD-based electrode architectures, including carbon-, hydroxide-, and conducting polymer-based composites, as well as flexible and transparent supercapacitors, are evaluated with respect to their electrochemical performance. Finally, the remaining challenges, including precise control of surface terminations, aggregation, long-term stability, and scalable synthesis, are discussed together with future perspectives for the rational design and practical implementation of high-performance MXQD-based supercapacitors.
Solid-state lithium-metal batteries (SSLMBs) are regarded as a next-generation electrochemical energy storage technology due to their potential for high energy density and enhanced safety. As a critical component, solid-state electrolytes (SSEs) significantly influence the performance of SSLMBs. Among various SE types, garnet-type Li7La3Zr2O12 (LLZO) electrolytes exhibit notable chemical stability against lithium metal, thereby attracting considerable attention. However, LLZO-based SSLMBs are still plagued by short-circuit failures caused by lithium dendrites. This review elucidates the origins of the issues related to SSEs, focusing on inherent imperfections such as high porosity and electron leakage at grain boundaries, as well as challenges at the interface between the SSEs and the lithium metal anode, including poor solid contact. Additionally, we summarize current strategies and recent research advances addressing lithium dendrite formation in garnet-type SSLMBs, aiming to support future development and technological breakthroughs in this energy storage technology.
Solid-state fluorescent materials with tunable visible emission are highly desirable for high-contrast latent fingerprint (LFP) visualization; however, most carbon dots (CDs) undergo aggregation-caused quenching in the solid state. In this study, we present a ligand-directed approach to engineer aggregation-induced emission (AIE)-active CD powders with tunable solid-state fluorescence (SSF) for forensic applications. The hydrothermally synthesized nitrogen-doped humic acid-derived carbon dots (N-hCDs) were functionalized with two aromatic aldehydic ligands via Schiff-base chemistry, producing CDs@I and CDs@D that display distinct light-red and yellow solid-state emission. The emission tuning arises from ligand-induced modulation of surface states, restricted intramolecular motion, and ordered lamellar self-assembly, which together suppress nonradiative decay in the aggregated state. The SSF powders enable high-contrast visualization of LFPs on diverse nonporous substrates, resolving level-2 and level-3 ridge features under UV illumination. Moreover, the materials exhibit excellent thermal stability, photostability, and aging resistance, underscoring their robustness for practical forensic applications. This work demonstrates a versatile surface-engineering strategy for color-tunable solid-state emissive CDs, broadening their utility in LFPs detection.
Achieving an optimal balance between energy and stability remains a fundamental challenge in high-energy-density materials (HEDMs). Additionally, from a practical perspective, it is highly desirable to develop energetic materials via fewer and more efficient synthetic steps to facilitate broader applicability. In this context, the energetic salt formation strategy offers advantages over the corresponding neutral analogues by enabling comparable energetic properties through simpler synthetic routes. Herein, a dicationic precursor, 4-amino-3,5-bis(aminomethyl)-1,2,4-triazole (1), was synthesized in a single step from readily available starting materials. Subsequent reaction with energetic acids afforded a series of high-performing and physically stable energetic salts (3-7). These salts exhibit enhanced stability relative to analogous salts derived from previously reported 1,2,4-triazole-based cations. All compounds were thoroughly characterized by IR, NMR spectroscopy, and elemental analysis. Compounds 6 and 7 were confirmed through 15N NMR spectroscopy, while salts 5 and 6 were elucidated through single-crystal X-ray diffraction analysis. Additionally, Hirshfeld surface analysis and 2D fingerprint plots were employed to establish structure-property relationships.
Here we have synthesized two mononuclear cobalt (II) complexes of type [Co(L)(L/)]ClO4, where L = 4-methyl-N,N-bis((1-methyl-1H-benzo[d]imidazol-2-yl)methyl)aniline, L/ = 2,2/ bipyridine (for 1) and 4,4/-dimethyl-2,2/ bipyridine (for 2). The synthesized complexes were characterized by various spectroscopic techniques and the molecular integrity of the complexes was confirmed by the single crystal x-ray diffraction (SCXRD) analysis. The redox properties of the complexes were analyzed by Cyclic Voltammetry (CV). The electrocatalytic proton reduction studies were done using acetic acid as an external proton source in a non-aqueous medium. The overpotential for the electrocatalytic proton reduction was found to be 453 mV for 1 and 470 mV for 2, consistent with increased electron donation to the metal center by the methyl group in 2, which shifts the reduction potential to more negative values and alters the overpotential. The turnover frequencies (TOF) were 217 and 203 s-1 for 1 and 2, respectively. A plausible catalytic mechanism was proposed based on the experimental observations. The post-catalytic analyses confirmed the structural integrity of the catalysts, indicating homogeneous behavior under catalytic conditions. This study aims to contribute to the development of sustainable and efficient hydrogen production technologies, supporting the transition toward a sustainable energy future.
Novel Cu/Cu2O-nanoparticles have been synthesized by the most economical electrochemical method utilizing metallic waste. 4-NP is a toxic pollutant affecting both animal and plant kingdom, necessitating its elimination from environment. This study demonstrates that the prepared nano-catalysts efficiently catalyse the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at room temperature under light condition. Further, the reduction process generates amine derivatives, which are intermediates in many industrial processes. This manuscript adheres to the principles of the circular economy by generating nanoparticles through the repurposing of metallic waste discarded by both industry and domestic users. Using scrapped copper from discarded air conditioner (AC) copper tubes as electrodes, we employed an electrochemical technique to develop Cu/Cu2O nanoparticles. The synthesized nanoparticles were characterized using field emission scanning electron microscopy (FE-SEM), transmission electron (TEM), EDX spectroscopy, powder x-ray diffraction (P-XRD), Fourier transformation infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, cyclic voltammetry (CV), and Brunauer-Emmett-Teller (BET) analysis. Our study confirms 99% conversion of harmful 4-NP to 4-AP in a rapid reaction time of 5 min. Synthesized nanoparticles can be reused up to four times without losing catalytic activity. UV-vis spectroscopy demonstrated that reduction follows pseudo-second-order kinetics and adsorption follows Freundlich isotherm model.
Understanding how small molecules modulate protein aggregation is pivotal for developing strategies against amyloid-related disorders. Polyphenols are promising modulators, yet the connection between their molecular photophysics and aggregation inhibition remains largely unresolved. In this article, femtosecond transient absorption spectroscopy has been employed to unravel the excited-state dynamics of some commonly used polyphenols, namely, Baicalein, EGCG, and Myricetin across varied environments-neat solvents, micelles and reverse micelles, and in the presence of globular and intrinsically disordered protein (in its native and aggregated forms). Excited-state intramolecular proton transfer (ESIPT) emerges to be highly sensitive to hydrogen-bonding, polarity, and local confinement, serving as a subpicosecond reporter of polyphenol-environment interactions. In protein systems, modulation of ESIPT dynamics signals environment-specific embedding of polyphenols within evolving protein landscapes. A unique tri-parameter correlation-linking binding affinities of the polyphenols to the native proteins, ESIPT lifetimes, and aggregation kinetics-reveals that inhibitory potency arises not from tight native binding but from selective engagement with aggregation-prone species. This work posits ESIPT as a sensitive molecular signature that links ultrafast photophysics to the functional inhibition of protein aggregation, providing new insights into how small molecules navigate complex biomolecular environments to regulate self-assembly pathways.
Single-atom and subnanocluster platforms are at the cutting edge of translational sensing technologies for future clinical use. Their dispersion at the atomic level ensures optimal metal utilization, clearly defined active sites, and precise control over electronic structures. By combining molecular accuracy with solid-state durability, these materials enhance the adsorption, charge transfer, and catalytic activation of key biomarkers, enabling highly sensitive and selective detection. This review covers recent progress in material design, mechanistic insights, and the integration of these materials into electrochemical and photoelectrochemical diagnostic devices. It also discusses significant challenges related to stability, scalability, and clinical adoption, all of which are crucial for transitioning from laboratory research to real-world medical applications.
In this study, we present a methodology for direct C─C bond formation using renewable primary alcohols as alkylating agents, catalyzed by base metal-derived Zn(II) complexes. We utilized two well-defined phosphine-free NNN bis-iminopyridine pincer ligands (L1 and L2) for the synthesis of zinc(II) catalysts C1 and C2, which were thoroughly characterized using UV-vis, IR, HRMS, and single-crystal x-ray diffraction techniques. Both complexes C1 and C2 effectively promoted the selective mono-alkylation of a variety of carbo-nucleophile, including aromatic ketones, α-tetralone, fluorene, and oxindole, by employing both aromatic and aliphatic primary alcohols as alkyl sources. A wide range of substrates, encompassing 42 derivatives, were investigated, resulting in isolated yields as high as 92%. The developed method was successfully applied at the gram scale, demonstrating its practical applicability and potential for scalability. Additionally, control experiments were performed to elucidate the reaction mechanism, and HRMS analysis verified the presence of significant Zn(II) intermediates involved in the catalytic process.
A halogen- and metal-free deep eutectic solvent (DES) consisting of choline hydroxide (ChOH) and urea (1:2) was employed as a green, reusable, and cost-effective medium for the one-pot synthesis of amide derivatives from aldehydes and hydroxylamines. The DES served simultaneously as solvent and catalyst, enabling the efficient formation of a wide variety of amides. The protocol afforded biologically and medicinally relevant compounds, including nicotinamide and bebenil, in excellent yields under mild conditions.
Innovation in polymeric membranes is playing a central role in addressing pressing challenges in the water, energy, and environmental sectors. This Special Issue highlights recent progress and emerging opportunities in sustainable membrane technologies for water purification, desalination, gas separation, fuel cells, batteries, supercapacitors, and carbon capture.
Here, an electrochemical sensor has been developed for the efficient determination of 2,4-dinitrophenol (2,4-DNP) in aqueous medium at neutral pH (7.0) phase. The chemical sensing probe was developed by modifying a flat glassy carbon electrode (GCE) with palladium-doped polypyrrole carbon-bismuth oxide nanocomposites (Pd@PPyC-Bi2O3 NCs), synthesized via a hydrothermal route. The electrochemical performance of the NCs fabricated with PEDOT:PSS conducting polymers modified electrode (Pd@PPyC-Bi2O3 NCs/PEDOT:PSS/GCE) was evaluated by using linear sweep voltammetry (LSV), which revealed a wide linear detection range (LDR) of 10.0 - 90.0 µM for 2,4-DNP. The calibration plot exhibited excellent linearity, with the sensor demonstrating a high sensitivity of 109.70 µA.µM- 1.cm- 2. The limit of detection (LOD) was obtained to be 0.92 ± 0.05 µM. In addition, the sensor exhibited good repeatability and stability under repeated measurements. Its practical applicability was further validated by successfully detecting 2,4-DNP in environmental collected waste water samples from different sources, with satisfactory recovery results. Overall, this study introduces a sensor Pd@PPyC-Bi2O3 NCs/PEDOT:PSS/GCE probe as a good electrochemical platform for efficient monitoring of 2,4-DNP by LSV, offering significant potential for environmental analysis and pollution control in a broad scales.
Aggregation-induced emission (AIE) has enabled the development of organic luminogens with enhanced emission in the aggregated state, offering significant potential for bioimaging applications. Herein, we report a series of tetraphenylethylene (TPE)-based small-molecule AIE probes for targeted cellular imaging. Four luminogens were rationally designed by functionalizing the TPE core with acid, ester, oxime, and ketal groups, affording TPE-Acid, TPE-Ester, TPE-Oxime, and TPE-Ketal. All compounds exhibit pronounced AIE characteristics, showing strong fluorescence in water-rich media and distinct stimuli-responsive emission behavior. Photophysical and theoretical studies reveal that emission properties can be effectively tuned through substituent variation. In vitro cytotoxicity assays using N2a (mouse neuroblastoma) cells confirm excellent biocompatibility. Live-cell imaging demonstrates that TPE-Acid and TPE-Ester produce strong intracellular fluorescence under violet excitation, whereas TPE-Oxime and TPE-Ketal emit efficiently under UV excitation. These findings highlight the effectiveness of substituent engineering on the TPE scaffold for modulating emission behavior and developing versatile AIE-active probes for biological imaging.
Herein, we report the synthesis of a carbon-supported palladium-based tri-metallic nanocatalyst (cat-G) and its successful application to facilitate the oxidative homocoupling of aromatic and aliphatic terminal alkynes. The catalyst contains significantly less amount of total metal content (20%) and was characterized using x-ray photoelectron and energy-dispersive x-ray spectroscopies, x-ray diffraction, thermogravimetric analysis, and transmission electron microscopy. Our implementation of EtOH as a solvent medium along with minimal catalyst loading for the synthesis of symmetrical 1,3-diynes under aerial oxidation without the aid of any ligand unveils simple and milder reaction conditions for C(sp)-C(sp) coupling reactions. The protocol displays a broad substrate scope, and the catalyst possesses simple recovery along with moderate recyclability up to five catalytic cycles.
Pyrazabole derivatives are widely used in liquid crystalline materials, ion sensing, multi-photon absorption, mechanochromism, luminescent polymers, and many more. The tetra-coordinate boron centers in pyrazabole exert a mild inductive electron-withdrawing effect, which modulates the electronic distribution and facilitates charge delocalization across the conjugated framework. The functionalization of pyrazabole with various donor and acceptor groups in both small molecules and polymeric frameworks has been extensively explored to optimize their optoelectronic properties. The review explores the design strategies for novel pyrazabole derivatives, focusing on fine-tuning of photophysical and electrochemical properties and advancements in the synthesis and functionalization of pyrazabole-based small organic molecules and polymers. The conformational flexibility of the pyrazabole unit allows it to adopt both planar and non-planar geometries, influencing the overall molecular architecture of the derivatives. In certain cases, this flexibility induces a distinctive bent arrangement depending on the substitution pattern and steric environment. This review highlights new avenues for innovative applications and advancements across various scientific domains, offering valuable insights into their potential contributions to ongoing research endeavors.
CO2-based polycarbonates show great potential for application as biodegradable pressure-sensitive adhesives (PSAs). However, it remains challenging for polycarbonate-based PSAs to achieve rapid surface wetting while simultaneously maintaining sufficient cohesive strength. To address this issue and improve adhesive performance, we propose a strategy for preparing crosslinked polycarbonate PSAs. As a proof of concept, bio-derived epoxides, including furfuryl glycidyl ether and n-butyl glycidyl ether, were introduced as key monomers to synthesize functionalized CO2-based polycarbonates (PBFCs). The crosslinked PSAs were subsequently constructed through a Diels-Alder reaction, while the flexible side chains enabled rapid wetting of the adhesive on the substrate surface. As a result, the static shear adhesion was significantly improved from approximately 0.1 h to over 24 h, accompanied by a tack grade of #2. Notably, the prepared PSAs could be reused for three cycles while maintaining a peel strength of approximately 2 N cm-1, and no visible residue was observed on the substrate after peeling. This study develops a series of crosslinked CO2-based PSAs from bio-based epoxides, providing a promising platform for the design of high-performance biodegradable PSAs.
The host-guest aqueous complexation gives rise to a library of crystal structures of distinct inclusion modes and solvation states, all assembled from p-sulfonato-calix[4]arene as a host and p-amino-benzamidine as a guest. Benefitting from single-crystal X-ray diffraction analysis and microscopic observation, we show that these host-guest structures emerge progressively from kinetically trapped highly solvated assemblies to thermodynamically favored inclusion complexes as a function of time and concentration. The host-guest system is also highly sensitive to solvent composition, as reflected in the alteration of 1H NMR spectra and crystallization behavior between water-alcohol and purely aqueous solutions. The work illustrates how crystallization can serve as a structural probe of pathway-dependent supramolecular maturation, enabling direct observation of kinetically and thermodynamically accessible assembly states in aqueous host-guest systems.
Castration-resistant prostate cancer (CRPC) is an advanced, treatment-refractory disease with high mortality and limited therapeutic options, necessitating novel metallodrugs with enhanced potency and reduced toxicity. Herein, we report the design and syntheses of two quinoline-benzazole hybrid bidentate ligands-2-(1H-benzo[d]imidazol-2-yl)quinoline (L1) and 2-(quinolin-2-yl)benzo[d]thiazol (L2)-along with four new half-sandwich ruthenium(II) arene chlorido complexes of the general formula [(η6-arene)(L)RuCl]PF6, where arene = benzene (Bz) or hexamethylbenzene (Hmb), yielding complexes 1-4. The ligands and complexes were fully characterized by spectroscopic (1H/1 3C NMR, IR, UV-vis) and analytical methods (elemental analysis, ESI-MS), with aqueous stability profiles confirming their suitability for biological evaluation. Cytotoxicity assays against the PC-3 CRPC cell line identified potent antiproliferative activity in selected complexes. Mechanistic studies revealed predominant G2/M phase cell cycle arrest, induction of apoptosis, and moderate-to-strong DNA binding affinities suggestive of intercalative/groove-binding modes. These results highlight the potential of quinoline-benzazole Ru(II) arene scaffolds as promising candidates for CRPC therapy, meriting further optimization.
The safe and robust synthesis of sodium and potassium salts of the [B(C6F5)4]- anion (Na[BArF20], 1-Na and K[BArF20], 1-K) via an improved method is reported. The implementation of the improved synthetic route to other tetraarylborate salts is carried out, which includes the synthesis of Na[B({CF3}C6H4)4] (Na[BArF12], 2) and Na[B({tBu}C6H4)4] (Na[BArtBu4], 3). The solid-state structure of the THF-solvated adduct of 2 is reported. 1-Na, 1-K, 2 and 3 are fully characterized by 1H, 11B, and 19F NMR spectroscopy.
