Photocatalysis has displayed potential for applications in remediation of organic contaminants as an environmentally friendly approach. Herein, sulfur-doped spherical carbon nitride (SCN-S) was successfully synthesized by introducing sulfur into spherical carbon nitride (SCN). The photocatalytic removal efficiency of sulfamethoxazole by SCN-S through activating peroxymonosulfate reached 99 % under solar light irradiation. Additionally, the photocatalytic degradation mechanism was elucidated based on the results of active species trapping experiments and electron paramagnetic resonance.

The heterogeneous Fenton-like process is a highly promising strategy for meeting global water purification demands. Yet, developing highly active and stable catalysts remains a key challenge for practical application. Here, we report a novel, unsupported Cu-modified porous tubular carbon nitride with high-density copper clusters (CuNx/CCN), fabricated via a simple Cu-induced self-assembly combining mechanochemical reaction and onestep pyrolysis. Small Cu clusters (22 wt% loading) are uniformly dispersed throughout the porous nanotubes. Polymerization temperature and time are key factors for CuNx/CCN nanotube formation: at 550 degrees C for 4 h, smaller hollow tubes further pyrolyze and curl into larger hollow structures. Leveraging both the porous tubular architecture and abundant active sites, CuNx/CCN shows remarkable H2O2 activation and efficient degradation of both cationic and anionic dyes, with good stability. Methylene blue (MB) removal reaches 99.9% within 30 min with H2O2, retaining 95.8% of catalytic efficiency after five cycles. Radical trapping experiments and EPR studies confirm that center dot OH, center dot O2-, and 1O2 co-contribute to the high catalytic activity, with center dot OH and center dot O2-playing pivotal roles. Synergy between cluster catalysis and Fenton chemistry, coupled with rapid Cu(I)/Cu(II) cycling, enhances reactive oxygen species generation and overall performance. This work expands iron-free Fenton-like systems and provides a rational design strategy for metal cluster catalysts in practical water purification.

Copper-based agents have been utilized widely in a range of commercial antibacterial products due to their superior release-killing antibacterial properties. However, the environmental concerns associated with the release of Cu2+ ions have restricted their application in textiles. In this study, Cu3P-ZnO nanocomposites with enzyme-like properties were synthesized through the phosphating of CuO-ZnO, and were employed to functionalize the surface of cotton fabrics using a dipping-padding-drying method. The physicochemical properties of the functional cotton fabrics were characterized using various techniques. The antibacterial efficacy of Cu3P-ZnO/cotton was assessed against Gram-negative E. coli and Gram-positive S. aureus bacteria. Remarkably, Cu3P-ZnO/cotton demonstrated significant antibacterial activity and stability without necessitating auxiliary conditions, achieving >99% antibacterial effectiveness against both E. coli and S. aureus, while retaining 94.7% efficiency after 50 washing cycles. The underlying antibacterial mechanism was elucidated, revealing that reactive oxygen species (ROS), especially singlet oxygen (O-1(2)), plays a crucial role in mediating the antibacterial action of Cu3P-ZnO/cotton in the absence of light, whereas direct contact between Cu3P-ZnO and bacteria plays a secondary role in this process. This research provides valuable insights into the design of ROS-mediated antibacterial agents for applications in antibacterial textiles.

Traditional mulberry leaf silkworm rearing is influenced by various factors, which limit the development of the sericulture industry. To overcome this problem, factory-based all-age artificial diet silkworm rearing has emerged as a viable alternative. As this is a new technology, studies on the aging properties of fabrics produced by this method are limited. In this work, degummed silk fabrics obtained from factory-based all-age artificial diet-rearing silkworms (referred to as artificial diet-reared fabrics) were compared with degummed silk fabrics obtained from traditional mulberry leaf-reared silkworms (referred to as mulberry leaf-reared fabrics). Both categories of fabrics underwent separate treatments of outdoor exposure, ultraviolet irradiation, and thermal aging. The findings showed that, in terms of surface morphology, no marked distinction was observed between the artificial diet-reared and mulberry leaf-reared fabrics either before or after aging. However, the aged artificial diet-reared fabrics exhibited a more pronounced color change, characterized by stronger yellowing compared with the aged mulberry leaf-reared fabrics. Furthermore, the beta-sheet structural content and crystallinity were consistently lower in the artificial diet-reared fabrics than in the mulberry leaf-reared fabrics under comparable conditions, both prior to and following the aging treatments. Owing to the influence of the beta-sheet structure content and crystallinity, the bursting strength and thermal stability of the artificial diet-reared fabrics were also lower than those of the corresponding mulberry leaf-reared fabrics. Although differences in these properties were observed between the two types of fabrics, the differences were relatively limited. With continued advances in factory-based all-age artificial diet rearing, silk fabrics produced from artificial diet-reared silkworms show the potential to gradually replace traditional mulberry leaf-reared silk fabrics.

Aliphatic polyesters show potential as substitutes for non-biodegradable materials, helping reduce plastic pollution. However, their synthesis often requires heavy metal catalysts, and conventional polyesters lack property diversity, limiting broader applications. Here, we developed an environment-friendly, multifunctional polyester as a versatile material. Cationic aggregation-mediated multifunctional polyesters have been effectively synthesized through a large-scale melt polycondensation process utilizing a carboxyl back-biting mechanism in the absence of any catalyst. Cationic aggregation in situ acts as a dynamic cross-linking point, enabling a single polymer to exhibit switchable and contrasting properties, transitioning between elasticity, transparency, and water-solubility and rigidity, opacity, and water-insolubility. Meanwhile, the material shows outstanding weldability at room temperature after fracture, and the welded material exhibits mechanical properties similar to the original material due to dynamic cross-linking points. The material exhibits a significantly higher degradation rate compared to traditional polyester, even under seawater conditions. Moreover, the polyester's switchable water solubility allows efficient separation from mixed plastics for closed-loop recycling. Additionally, replacing with antibacterial cations can upcycle the polyester into high-value antibacterial materials, enhancing sustainability. This work provides insights into the design of multifunctional, catalyst-free and sustainable polyesters for a broad range of applications.

The development of highly efficient and stable nonprecious metal bifunctional electrocatalysts is crucial for reducing the cost and improving the performance of zinc-air batteries. Leveraging the structural stability and tunability of covalent organic frameworks, we have constructed a novel hybrid covalent organic catalyst via a pyrolysis-free approach. The remarkable catalytic activity of this catalyst is due to the synergistic interaction among the atomically dispersed Fe-N4 sites, superfine NiOx nanoparticles, and the incorporated diarylamine redox-active units. Such a rational design results in excellent bifunctional electrocatalytic capacity in an alkaline electrolyte and a low potential gap of 0.634 V, which is better than the noble-metal standard of Pt/C + IrO2. Batteries made with this catalyst exhibit a peak power density of 158.8 mW cm-2 and excellent cycling stability, demonstrating its potential for practical applications. This work offers a new approach to the rational design of high-performance nonprecious metal bifunctional electrocatalysts with well-defined structures.

In recent years, supercritical CO2 (scCO2) foaming fibers have attracted considerable attention. However, the preparation of microporous structured foamed fibers is immature. Currently, the combination of foaming and spinning is an emerging topic, full of challenges. During the processing, the preparation of microcellular foamed fibers necessitates a thorough understanding of the foamability, thermal properties and rheological properties of the material. These properties significantly influence the performance of nucleation, and the distribution of cells. In this work, comprehensive analysis of PET foamability, thermal properties and melt rheology was conducted, rheology encompassing all critical processing stages, including melting in the twin-screw section, homogenization in the single-screw section, extrusion through the spinneret, and subsequent stretching after extrusion. The rheology of the entire process is of paramount importance, as this work aims to contribute to the research on the preparation of spinning microporous ultrafine foamed fibers.

With the development of artificial diet-based rearing technology, differences in rearing systems now affect the characteristics of silkworm (Bombyx mori) silk fibers. Forced reeling, a green and non-destructive modification method, has shown significant potential for the preparation of high-performance silk fibers. However, comparative studies on the characteristics of forced reeled silk fibers under different rearing systems are limited. The aim of this study was to compare and analyze the structure and properties of forced reeled silk fibers derived from a mulberry leaf-based rearing system (ML-FRs) and forced reeled silk fibers derived from an artificial diet-based rearing system (AD-FRs) under different reeling speeds. Silkworms reared on artificial diet exhibited better adaptability to forced reeling and AD-FRs exhibited higher strength, stiffness, and thermal stability than ML-FRs. When the reeling speed reached 40 mm/s, the tensile strength and Young's modulus of AD-FRs (712.29 ± 55.69 MPa and 16.10 ± 2.43 GPa, respectively) were higher than those of ML-FRs (649.60 ± 61.90 MPa and 14.45 ± 1.78 GPa, respectively). These results were attributed to the combined effects of differences in the adaptability of silkworms during forced reeling and changes in the secondary structure, crystallinity, and crystal orientation of the forced reeled silk fibers. This study revealed the mechanisms by which rearing systems and reeling speeds affect the structure and mechanical properties of forced reeled silk fibers, providing a theoretical basis and practical guidance for selecting rearing systems and reeling speeds to produce high-strength and high-modulus silk fibers when using forced reeling.

High-capacitance fiber-shaped supercapacitors (FSCs) based on graphene fibers offer remarkable advantages, including high power density, long cycling lifespan, and versatile wearing potential. However, the inherent challenges associated with single-component frameworks, such as restricted ion-accessible active sites and sluggish interfacial ion-transport kinetics, severely hinder their optimal electrochemical storage performance. Herein, heterogeneous, redox-active MnO/Fe3C@graphene fibers (MF@GF) are designed and synthesized to achieve FSCs with high energy density. Benefiting from the synergistic integration of abundant active sites, oxygen vacancies, and constructed interfacial conduction routes, MF@GF features multiple redox reactions, low diffusion barriers, and fast adsorption/conduction kinetics. Consequently, MF@GF-based FSCs offer ultrahigh areal capacitance (5218.7 mF cm- 2 at 5 mA cm- 2) and remarkable rate performance (4071.5 mF cm- 2 at 30 mA cm- 2) in a 6 M KOH electrolyte. Furthermore, MF@GF-based all-solid-state fiber-shaped supercapacitors (ASFSCs) deliver a maximum energy density of 49.85 mu Wh cm- 2 and a power density of 0.38 mW cm- 2, along with a favorable cycling performance of 86.84% capacitance retention after 10,000 cycles. Moreover, these devices demonstrate broad adaptability for flexible and wearable energy-supply applications and can be integrated into various textiles to power wearable electronics, such as hygrothermographs and smartwatches. This approach offers valuable insights into the development of high-capacitance, multifunctional, smart FSCs for nextgeneration, efficient wearable energy systems.

As a novel class of fluorescent nanomaterials, carbon quantum dots (CQDs) require a deep understanding of their photoluminescence mechanisms to achieve precise control over their material properties. This study elucidates the formation mechanism of nitrogen-doped carbon quantum dots (N-CQDs) derived from folic acid (FA) and reveals the molecular origin of their photoluminescence. A time-dependent hydrothermal synthesis strategy was employed, combined with multi-dimensional characterization techniques including high-performance liquid chromatography-mass spectrometry (HPLC-MS), proton nuclear magnetic resonance (1H NMR), and fluorescence spectroscopy, to successfully track and isolate key molecular intermediates formed during the synthesis. The study identified three molecular fluorophores—POPP, TOIP, and PPD—whose photophysical properties closely match those of the final CQDs, confirming their role as the molecular origin of photoluminescence. Based on comparative experiments using structural fragments of the precursor, a complete evolutionary pathway was elucidated, in which FA undergoes a series of reactions such as dissociation, recombination, and cyclization under hydrothermal conditions, with nitrogen doping (via o-phenylenediamine) redirecting the pathway to form distinct fluorophores and carbon structures. This study not only provides direct molecular-level evidence for the luminescence mechanism of FA-derived CQDs but also establishes a framework for understanding how molecular intermediates govern the formation and emission properties of functionalized CQDs.

A ternary cobalt phthalocyanine/carbon quantum dot/graphitic carbon nitride (CoPc/CD/CN) photocatalyst was rationally engineered via an HCl-assisted hydrothermal strategy for visible-light-driven degradation of dye pollutants in hypersaline wastewater. Acid-induced surface protonation enhanced selective adsorption of anionic Orange Acid 7 (OA7), while maintaining efficient degradation of Rhodamine B (RhB). The optimized Co3CD20CN achieved about 98% OA7 removal within 16 min and 99% RhB degradation within 50 min. The incorporation of CoPc and carbon dots promoted interfacial charge transfer, broadened visible-light absorption, and effectively suppressed charge-carrier recombination, resulting in markedly enhanced photocatalytic performance. In addition, the composite exhibited excellent salt tolerance (200 mM NaCl), wide pH adaptability (3–9), and good cycling stability, demonstrating its applicability in complex aqueous environments. Mechanistic studies revealed a •O2–-dominated oxidation pathway with h+ participation, which alleviates chloride interference and minimizes chlorinated byproduct formation under saline conditions. This work provides an interfacial engineering strategy for designing superoxide-driven photocatalysts for safer and more efficient treatment of high-salinity dye wastewater.

Polyamide 6 (PA6) is inherently flammable and releases substantial heat during combustion, which restricts its widespread application. While conventional 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based flame retardants exhibit notable efficiency, their ability to catalyze char formation in PA6 remains limited, hindering effective heat suppression. To address this challenge, a phosphorus-containing transition metal complex, BPMNi, was synthesized by strategically integrating nickel(ii) with a tailored DOPO-derived ligand. The introduction of the metal element aimed to enhance catalytic carbonization during combustion. After melt blending, the composite containing BPMNi (PA6/BPMNi-3) achieved a limiting oxygen index of 31.5% and passed the vertical burning test with a V-0 classification. Its peak heat release rate and total heat release values were reduced to 653 kW m-2 and 40.0 MJ m-2, representing decreases of 40.3% and 55.2%, relative to neat PA6. The flame-retardant behavior and suppression of heat release stemmed from a dual-action mechanism. In the gas phase, high-energy free radicals were captured, terminating the chain reaction of the combustion process. Meanwhile, in the condensed phase, a robust and thermally stable char layer formed on the PA6 matrix surface, acting as a protective shield.

The extensive consumption and inadequate management of polyamide 6 (PA6) fibers have resulted in significant​ environmental pollution, potential health risks, and wastage of carbon resources. To mitigate the environmental impact of PA6 waste, this work developed an environmentally selective photodegradable PA6 fiber material by incorporating a photocatalyst into PA6 matrix via a centrifugal-electrospinning technique. The photodegradable PA6 fiber material demonstrated a significant mass loss of 38 % after 120 h of irradiation in an aqueous solution at pH 3. Notably, it exhibited exceptional stability across a broad pH ranging from weakly acidic to strongly alkaline conditions. The results indicate that the material exhibits excellent stability under conventional storage and use conditions, while enabling rapid degradation under specific scenarios. This dual functionality achieves an effective balance between service life and rapid degradability. Furthermore, the degradation mechanism analysis of PA6 macromolecular indicates that chain scission is predominantly initiated by the cleavage of amide, C–N, and C–C bonds. This scission will generate intermediates terminated with functional groups including -NH2, -CHO, -CH3, and imides, which are subsequently mineralized through oxidation. The analysis of the chain scission mechanism provides a reference for the degradation mechanism of amide polymers.

The electrocatalytic transformation of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA), an essential monomer for bioplastic production, is a key step in sustainable biomass refining. Herein, NiCoFe layered double hydroxides supported on nickel foam (NiCoFe LDHs/NF) were effectively fabricated via a simple one-pot hydrothermal approach for the electrocatalytic HMF oxidation reaction (HMFOR). The catalyst featured a hierarchical nanosheet architecture with abundant accessible active sites. The interplay between Ni, Co, and Fe optimised the electronic configuration and promoted efficient charge transfer, thereby endowing the catalyst with outstanding catalytic performance in the HMFOR. The NiCoFe LDHs/NF electrode achieved 100% HMF conversion with an FDCA yield and Faradaic efficiency (FE) of 99.8% and 99.6%, respectively. Moreover, it demonstrated outstanding cycling stability, retaining 100% HMF conversion with an FDCA yield and FE exceeding 98% after 25 successive cycles. Through comprehensive experimental research and density functional theory calculations, this study revealed that the exceptional HMFOR activity of the catalyst arises from cooperative interactions among Ni, Co, and Fe. This behaviour tuned the electronic structure and significantly reduced the activation energy of the rate-determining step. Overall, this study presents a feasible design approach for ternary LDH catalysts to advance efficient and stable biomass electrocatalytic conversion systems.

Bone defect repair is a multistage physiological process that coordinates cellular responses with extracellular matrix remodelling and inflammatory regulation. Osteogenic differentiation not only contributes to structural support but also provides bioactive agents that modulate the immune microenvironment, thereby promoting bone regeneration by actively polarizing macrophages. In this study, a borophene and alendronate-grafted silk fibroin/carboxymethyl chitosan composite hydrogel was prepared to enhance biomineralization and promote effective osteogenic differentiation. The structural integrity of the composite hydrogel was confirmed through various physicochemical characterizations. Then, an ecotoxicity analysis using the Artemia salina bioassay confirmed the non-toxicity of hydrogel materials. The composite hydrogel also demonstrated strong antibiofilm activity against S. aureus and E. coli in a dose-dependent manner at concentrations of 25 mu g/mL and 50 mu g/mL. Furthermore, pre-osteoblast cells treated with the hydrogel material demonstrated biocompatibility, cell adhesion, proliferation, and migration, as evidenced by wound scratch assays. Significantly, osteogenic differentiation was verified by alkaline phosphatase and alizarin red S staining, which confirmed mineralization. The immunofluorescence analysis further discovered regulation of osteogenic and angiogenic markers, including RUNX2, OCN, and VEGF, validating the composite hydrogel's ability to promote bone matrix formation and vascularization. The in vivo studies demonstrated that the hydrogel scaffolds effectively promoted tissue regeneration while significantly inhibiting osteoclast activity. Macrophage polarization evaluation of the composite hydrogel showed that it effectively immunomodulated macrophages from the pro-inflammatory M1 phenotype to the antiinflammatory M2 phenotype, thereby facilitating tissue remodelling and reducing inflammation. These findings indicate that the SF/CMC/Bp@ALN composite hydrogel scaffold has superior multifunctional properties, making it a suitable biomaterial for orthopedic bone tissue engineering applications.

This study investigates the role of chemical tethering in polymer dynamics within the framework of Adam-Gibbs (AG) theory, employing star polystyrene (PS) as a model system, with each arm capped with an adamantane (Ad) group and varying the number of arms (f) and core rigidities. Results indicated that the glass transition temperature (T g) and dynamic fragility (m) of the Ad-capped star PS increased with an increasing f value and core rigidity. These increases were associated with an increase in the potential energy barrier per monomer segment (Delta mu), as described by the AG theory, but with an unaltered length for cooperatively rearranging regions at T g, establishing a linear relationship between Delta mu and T g and m. This relationship indicated that chemical tethering impedes polymer cooperative dynamics by constraining the internal rotation of C-C bonds in the tethered polymer backbone and increasing the Delta mu value during cooperative motion. The findings of the study offer new insight into the polymer glass transition, which varies according to the molecular topology and tethering architecture of the polymer.

In traditional polyphosphoric acid (PPA) systems, polybenzoxazole (PBO) synthesis suffers from long reaction times and high energy consumption. To address this, a rapid model-reaction-based screening protocol using the terephthalic acid (TPA)/o-aminophenol (OAP) system was developed to qualitatively rank catalyst activity. Fourteen imidazole-based derivatives were evaluated, revealing structure-activity trends and enabling selection of two optimal catalysts, 4,5-dimethyl-2-phenyl-1H-imidazole (Cat-2) and 2-methyl-1H-benzimidazole (Cat-3). Both accelerated polymerization of aromatic AB-type monomers (3,4-AHBA, 4,3-AHBA, 3,4-AHPA & centerdot;HCl, ACBP), yielding polymers with higher intrinsic viscosities within the same reaction times. The resulting PBOs maintained intact benzoxazole backbones and exhibited excellent thermal stability under nitrogen (T 5% = 598 degrees C-654 degrees C; char yield 67%-72%). Solid-state 13C NMR, FT-IR, XPS, and TGA, together with viscosity measurements, support a plausible mechanism in which imidazole catalysts may form N-acyl-imidazole intermediates, facilitating acyl transfer and lowering the early condensation barrier. Overall, this work proposes an efficient catalytic strategy and mechanistic insights for the investigated aromatic AB-type PBO monomers, providing guidance for catalyst design in related PBO and heterocyclic polymer systems.

Flame-retardant modification of polyamide 66 (PA66) typically leads to a reduction in mechanical properties, as the steric hindrance effect of flame retardants weakens the intermolecular forces and affects the crystallization behavior, thereby limiting its broader applications. In this work, a reactive flame retardant (TAP), composed of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and triazole structures, was synthesized and employed to fabricate inherently flame-retardant PA66 copolymers via a straightforward synthetic route. Incorporation of 4 wt % TAP into PA66 (denoted as PA66-co-TAP-4) endowed the copolymer with a limiting oxygen index (LOI) of 30.2% and a V-0 rating in the vertical burning (UL94) test. Compared with pure PA66 (80.9 MPa), PA66-co-TAP-4 achieved a higher tensile strength of 85.6 MPa. Synergistic effects of gas-phase radical quenching, fuel dilution, condensed-phase barrier action, and TAP-copolymer hydrogen-bonding interactions render PA66-co-TAPs with superior flame resistance and improved mechanical performance. This work provides a viable strategy to enhance the fire safety of PA66, thereby, significantly expanding its practical application value.