RSC Advances最新文献

Crafting a high-performance electrochemical sensor for chlorogenic acid (CGA) holds substantial value for advancing periodontal disease (PD) management and therapeutic strategies. In this investigation, we synthesized a graphdiyne (GDY)-platinum nanoparticle (Pt NP) hybrid (Pt/GDY) via a straightforward electroless plating technique, leveraging the complementary strengths of its components: Pt NPs mitigate GDY aggregation and enhance electrocatalytic activity, while GDY provides large surface and exceptional binding affinity toward CGA. Utilizing this Pt/GDY nanocomposite as the electrode modifier, we engineered an efficient CGA electrochemical sensor. Following optimization of critical detection parameters, including solution pH, Pt/GDY amount and incubation time, the Pt/GDY-based sensor demonstrated outstanding analytical performance, enabling ultrasensitive CGA quantification with a linear range of 0.008-2 µM and a detection limit of 2 nM. Furthermore, the sensor exhibited favorable selectivity against interfering species, long-term stability, consistent reproducibility, and reliable applicability in real samples. These superior characteristics position the Pt/GDY sensor as a promising tool for quality control assessments and drug metabolism studies in PD treatment regimens.

Conventional ionic liquids (ILs) used for cellulose modification, while effective in dissolving cellulose, often induce a transition from the robust cellulose I crystalline structure to the weaker cellulose II crystalline phase, compromising material strength. To overcome this limitation, we developed six types of tetrabutylammonium (TBA)-based organic salts, including TBA acetate, aimed at modifying the cellulose surface while preserving its native crystalline structure. Regenerated cellulose nanofibers (CNFs) treated with these TBA-based salts were analyzed via X-ray diffraction and scanning electron microscopy, revealing that TBA maleate minimally affected crystallinity and retained the cellulose I crystalline structure. Subsequently, TBA maleate was employed as the solvent medium for the surface modification (acetylation) of CNFs, achieving a degree of substitution of 0.5. The modified CNF acetate (CNF-ac) was blended with commercial cellulose acetate (CA) at ratios of 1, 3, and 5 wt% to evaluate its reinforcing potential. The cellulose I-rich CNF derivative exhibited superior dispersion within the CA matrix, leading to a 46% enhancement in mechanical properties. Overall, this study highlights the potential of crystalline structure-preserving organic salts for the development of high-performance cellulose-based composite materials.

The efficient and low-energy treatment of dye wastewater remains a significant challenge. Herein, a novel co-sensitized TiO₂ photocatalyst (CS-TiO₂) was constructed by combining ruthenium-based dye N719 with a laboratory-synthesized organic dye RA, aiming to extend the visible-light absorption range. The CS-TiO₂ was subsequently embedded into poly(methyl methacrylate) micro-nano fibers via centrifugal spinning, yielding easily recyclable photocatalytic membranes. After deducting the 30% self-degradation contribution of methylene blue arising from its intrinsic photosensitizing effect, the as-prepared PMMA/CS-TiO₂ membrane achieved a net MB degradation efficiency of 58.12%-significantly superior to that of single-dye sensitized counterparts. This enhanced performance is ascribed to efficient charge separation and boosted production of dominant ·OH radicals enabled by the synergistic co-sensitization effect. Notably, the membrane retained ∼80% of its initial net degradation efficiency after five consecutive cycles, demonstrating excellent reusability and structural stability. This work offers a promising approach for constructing efficient, sustainable, and recyclable photocatalytic systems for dye wastewater remediation.

The green synthesis of metal nanoparticles (NPs) has been of growing interest, in part because it is environmentally friendly, less toxic, and uses plant-derived phytochemicals as natural reducing and stabilizing agents, providing a more sustainable approach to traditional chemical synthesis. This study reports the green synthesis of silver NPs (Ag NPs) from aqueous leaf extracts of Echinops ritro and Echinops spinosus and assesses the comparative antibacterial and photocatalytic properties. The optical band gap energies of Ag NPs grown using both plants were determined to be 2.76 eV and 2.78 eV, respectively. FTIR, SEM, and XRD analyses have identified the functional groups in the formation of polydisperse NPs and validated their size and crystalline structure. The synthesized Ag NPs-ES demonstrated the best antibacterial activity with a maximum inhibition zone (24.66 mm) against S. aureus. In comparison, the zone of inhibition (ZOI) against other strains was 24 ± 1, 21.66 ± 0.88, and 21 ± 0.57 mm for B. licheniformis, B. Subtilis, and E. coli, respectively, while Ag NPs-ES showed the same trend in the maximum ZOI against S. aureus (22.33 ± 0.33 mm), followed by B. subtilis (20.66 ± 0.66 mm), B. licheniformis (15.33 ± 0.88 mm), and E. coli (15 ± 0.57 mm). The photocatalytic degradation of methylene blue (MB) and methyl orange (MO) dyes under sunlight was more prominent with Ag NPs from E. spinosus (80% & 88%) than from E. ritro (71.2% & 74.8%), following pseudo-first-order kinetics with higher rate constants. The results supported that E. ritro and E. spinosus-capped Ag NPs are potent, environmentally friendly materials with potential applications in antibacterial formulations and wastewater treatment.

Redox-mediated flow batteries (RMFBs) are a promising, emerging energy storage technology and have the potential to drastically increase the capacity of conventional redox flow batteries (RFBs) while maintaining their architectural flexibility. In these systems, a solution-phase active material is pumped between the RFB cell stack and storage tanks and is responsible for direct charge/discharge of the battery system. This material acts as a redox mediator (RM) between the electrochemical apparatus and a solid active material (SAM), which remains in the storage tanks and comprises the capacity of the system. Characteristics of the indirect electrochemical reaction between RM and SAM, which occur in the storage tank, external to the RFB stack, have so far been inferred from conventional RFB performance metrics. Herein, we report a study of this heterogeneous process that is based on spectroscopic measurements, carried out on the active materials, rather than interpretation of distal electrode processes. This provides independent information on the SAM's state-of-charge, a critical property of RMFB performance that is typically not measured directly. Further, we demonstrate that the redox reaction between the RM and the SAM, which is required for efficient operation, may be tuned by hundreds of mV, or even completely inhibited, by altering the type and concentration of supporting ions in the electrolyte. Finally, we report a periodic-DFT investigation of the vibrational spectroscopy of the SAM, which lays the groundwork for a thermodynamic framework that will be used to characterize and optimize the indirect electrochemical reaction.

The aldehyde-functionalized pyrazolo[3,4-b]pyridine derivative CJ129 was examined in the solid state for the first time using single-crystal X-ray diffraction. The analysis showed that the molecule adopts a monoclinic P2₁/c arrangement, in which the packing is supported by π-π stacking interactions of 3.683 Å between the molecules. To gain a broader picture of its behavior, we combined several quantum-chemical approaches-DFT using M06-2X/def2-TZVPP and TD-DFT with CAM-B3LYP/6-311++G(d,p)-to explore its electronic properties, chemical reactivity, and nonlinear optical (NLO) response. CJ129 features a moderate HOMO-LUMO separation (6.17 eV), a notably high electrophilicity index (ω = 70.31 kcal mol^-1), and clear evidence of intramolecular charge transfer, all of which contribute to its strong NLO behavior (β = 26.81 × 10^-30 esu; γ = 118.34 × 10^-36 esu), which exceeds the values reported for chalcone-based systems. To complement the electronic analysis, we performed 500-nanosecond molecular dynamics simulations of the complex with VEGFR-2. Throughout the trajectory, CJ129 remained stably positioned in the active site, mainly through hydrophobic interactions and recurring hydrogen bonds involving Asp1046 and Asn923. Taken together, these results provide the first integrated crystallographic and computational description of CJ129 and suggest its potential as an NLO-active molecule and promising scaffold for targeting VEGFR-2 in antiangiogenic research.

Polymer dielectrics are widely used in the fabrication of dielectric capacitors due to their excellent insulating properties. However, the relatively low dielectric constant (ε _r) limits the energy storage density (U _d) of polymer dielectrics. This study fabricated P(VA)MMA composite films by incorporating ultralow-content (<0.1 wt%) PVA into PMMA matrices. By systematically varying the PVA doping concentration (0.025-0.075 wt%), the ε _r and U _d were effectively optimized. Notably, the P(VA_1)MMA film with 0.025 wt% PVA doping concentration achieved a high U _d of 7.83 J cm^-3 at 580 MV m^-1 electric field, representing a 29.64% enhancement compared to pure PMMA film while maintaining an energy storage efficiency of 86.34%. This study successfully developed all-organic dielectric materials with significantly enhanced dielectric constant and energy storage properties at ultra-low doping concentrations, which holds important implications for the advancement of dielectric capacitors.

Metal-organic frameworks (MOFs) offer a versatile platform for designing high-performance supercapacitor electrodes, but their poor intrinsic conductivity and structural instability limit practical application. Here, we report an silver-citrate-modified NiCo₂S₄@calcined-MOF composite derived from a trimetallic NiCoZn-MOF template for hybrid supercapacitor electrodes. The parent NiCoZn-TPA MOF is first calcined to form a porous NiO/CoO/ZnO/carbon framework that provides mechanical robustness and enhanced conductivity. NiCo₂S₄ nanoparticles are then grown in situ on this scaffold, followed by the incorporation of silver-citrate to introduce additional redox-active sites and highly conductive Ag pathways. Structural and chemical characterization confirms the successful formation of a plate-like oxide-carbon framework uniformly decorated with NiCo₂S₄ and silver-citrate nanoparticles. The optimized composite (A4, 60 wt% NiCo₂S₄@calcined-MOFs/40 wt% silver-citrate) delivers a high specific capacity of ∼836C g^-1 at 0.5 A g^-1 in 1 M KOH. An asymmetric device based on A4//activated carbon achieves an energy density of 94 Wh kg^-1 at 577 W kg^-1, while maintaining high-rate capability and 82% capacitance retention after 5000 cycles with 98% coulombic efficiency. Dunn analysis reveals combined faradaic and capacitive contributions, highlighting the hybrid charge-storage behavior of this MOF-derived multicomponent electrode architecture.

This review examines mechanochemical synthesis as a solvent-free and scalable approach for high-performance CO₂ reduction catalysts. Mechanical energy-driven methods, particularly high-energy ball milling, enable controlled defect formation, enhanced metal-support interactions, and atomic dispersion, thereby improving CO₂ activation and conversion. Recent advances are discussed across major reaction pathways, including methanation (>99% CH₄ selectivity), light olefin production (55.4% selectivity), photocatalytic CO₂ reduction (CO production up to 306.1 µmol g^-1 h^-1), and integrated capture utilization systems. Structure performance relationships and techno-economic aspects are evaluated, highlighting 60-90% waste reduction and 20-50% energy savings relative to conventional synthesis. Overall, mechanochemistry represents a versatile and scalable platform for advancing sustainable CO₂ valorization strategies.

Early osteoarthritis (OA) with reversible ability appears to lack features other than intense acute inflammation. Herein, we developed a pH-responsive metal organic framework (MOF) system based on phenylboronic acid (PBA) and O-hydroxyl pH-dependent reversible switches. Click chemistry enables a simple and environmentally friendly synthesis process and sensitive drug release procedure. Nanoparticles possess excellent photothermal conversion capabilities that enable thermal interventions alongside sustained drug release, thereby treating early OA in multiple ways. The results indicate that nanoparticles have high drug-loading capacity and can respond to the weakly acidic conditions in the OA microenvironment to release ellagic acid (EA) gradually. It can also significantly reduce inflammatory reactions induced by IL-1β. The high effectiveness of this compound therapy is comprehensively demonstrated by both in vitro and vivo evidence.