Materials Horizons最新文献

The concurrent gold detection and extraction in aqueous medium is crucial for gold exploration and resource recovery. While using a single material for dual purposes offers distinct advantages, it remains relatively underexplored. This study introduces a rationally engineered heterojunction material that enables selective fluorescence-based turn-on gold detection in the near-IR region, coupled with photocatalytic enhanced adsorption. The hybrid composite material (NSCD@DFNS@BMB-AO) consists of dendritic fibrous silica integrated with in situ grown N,S-doped carbon dots (NSCDs) as a fluorescence indicator in the silica matrix and covalently attached amidoxime ligands for gold binding. The incorporation of NSCDs enables photoluminescence in near-IR regions while also promoting photocatalytic activity. The material uniquely enables turn-on gold-ion detection in the near-IR region through photoinduced electron transfer (PET) disruption, offering an ultra-low detection limit (LOD) of 9.9 nM with excellent selectivity. The adsorption potential of the material (780 mg g^-1) was enhanced through the photocatalytic reduction of Au(III) to Au(0). Furthermore, the ROS (reactive oxygen species) activity contributes to the material's antimicrobial properties, which are essential to prevent biofouling in aquatic environments. With its rapid response, fast kinetics, effective adsorption capability, and nearly complete gold recovery (∼98%) from e-waste, this material demonstrates significant potential for gold extraction and recovery.

Nitrogen-rich energetic materials have attracted significant attention due to their remarkable enthalpy of formation and superior detonation performance. However, the inherent high mechanical sensitivity continues to pose significant applications limitations. In this work, a novel structural design featuring direct C-C linkages between central tetrazole rings was developed, replacing conventional indirect connections through NN bridges, thereby significantly enhancing thermal and mechanical stability. Besides, the salt formation strategy has also been demonstrated as an effective approach for sensitivity regulation. Through the combined implementation of direct C-C linkage and salt formation strategies, a series of tetrazole-based energetic materials, including neutral compounds H2TT and H2QT, as well as their energetic salts (K2TT, KHTT, NaKQT and 1-6) were successfully synthesized. Notably, the neutral compound H2QT exhibits an exceptionally high enthalpy of formation (Δ_fH_m = 1560.93 kJ mol^-1/5.69 kJ g^-1). Among the target compounds, hydrazine salt 4 has the most balanced properties with nitrogen content reaching 82.82%, enthalpy of formation of 1589.97 kJ mol^-1/4.70 kJ g^-1, detonation velocity of 9146 m s^-1, decomposition temperature of 242 °C, impact sensitivity of 15 J and friction sensitivity of 240 N. This work successfully establishes the synthetic methodology for expanding from tritetrazole to tetratetrazole systems, thereby providing a fundamental strategy for the future development of extended-chain tetrazole-based compounds.

Porous organic cages (POCs) are promising crystalline porous materials with high porosity, but their conventional solvothermal synthesis is time-consuming and energy-intensive. Herein, we report for the first time an ultrafast sonochemical approach (<5 minutes, ambient temperature) for synthesizing imine-linked POCs (Sono-CC3R-OH, Sono-CC3R, and Sono-NC2R) using methanol as a green solvent. The sonochemically synthesized POCs exhibit exceptional porosity and crystallinity, outperforming their solvothermal counterparts, while achieving a ∼78% reduction in energy consumption. Furthermore, this approach exhibits excellent potential for large-scale production and efficient solvent recyclability. High-surface-area Sono-CC3R-OH demonstrates preferable CO₂ adsorption with a CO₂/N₂ selectivity of up to 77.5. Thus, this work opens a quick and efficient pathway for the synthesis of imine-linked POCs with superior surface area, offering great potential for the scalable production of gas adsorbents.

Emerging immunotherapies have demonstrated remarkable potential in cancer treatment. However, persistent challenges including insufficient immune activation and limited tumor infiltration remain unresolved. Here, we introduce focused-ultrasound (FUS) responsive artificial killer cells (AKCs), a novel biomimetic system integrating functions of natural killer (NK) cells, dendritic cells (DCs) and macrophages for closed-loop tumor immunotherapy. AKCs consist of lanthanide nanoparticles integrated within a hybrid lipid membrane, which not only improves biocompatibility but also enables real-time monitoring through near-infrared (NIR) imaging. Compared to traditional liposomal formulations, AKCs demonstrate superior tumor targeting and retention properties, significantly improving the reliability of diagnostics and therapeutic efficacy. The innovative use of FUS allows for controlled release of copper cations, which, in conjunction with the recruitment of dendritic cells via RANTES (regulated on activation, normal T-cell expressed and secreted) cytokine release, transforms the immunosuppressive tumor microenvironment to immunologically active states. Cuproptosis induced by AKCs can significantly enhance tumor elimination efficacy. Tumor bearing mice exhibited prolonged survival and tumor regression with AKCs exhibiting superior tumor targeting and sustained antitumor effects. This research highlights a multifaceted approach to cancer immunotherapy, combining innate and adaptive immune activation mechanisms, thereby suggesting a promising direction for future advancements in targeted cancer therapies.

With the ever-increasing demand for the miniaturization of polymer capacitors, it is imperative to develop polymer dielectrics with high energy densities, which typically require a combination of high dielectric constant (ε_r) and high breakdown strength (E_b). Currently, incorporating high-ε_r nanofillers into a polymer matrix is considered an effective strategy to enhance the dielectric constant of polymer dielectrics. However, this improvement is often achieved at the expense of reduced breakdown strength. Here, a kind of heterogeneous carbon/silica nanosphere (HCS NS) with abundant internal interfaces is synthesized to enhance the dielectric constant of poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) polymer by strengthening interface polarization. Meanwhile, the heterogeneous interfaces also suppress the development of breakdown pathways, thereby preventing excessive deterioration of breakdown strength of the polymer composite. Subsequently, the obtained HCS/P(VDF-HFP) composites are stacked with polyetherimide (PEI) polymer, forming HCS/P(VDF-HFP)-PEI layered composites. Benefiting from the synergistic effect between the high-ε_r HCS/P(VDF-HFP) layer and high-E_b PEI layer, a bilayer composite with 2.5 wt% HCS NSs achieves a significantly enhanced discharge energy density of 10.81 J cm^-3, which is about 206.3%, 176.1% and 133.5% that of P(VDF-HFP), PEI and the P(VDF-HFP)-PEI composite, along with a high efficiency of 93.8%. It should be noted that the composite retains a high discharge energy density of 9.22 J cm^-3 and a discharge efficiency of 90.1% even under an elevated temperature of 100 °C. This strategy of combining heterogeneous nanofillers with a layered dielectric structure provides an effective approach for improving the energy storage performance of dielectric composites.

Nematic liquid crystals are anisotropic fluids which have long-range one-dimensional orientational order and short-range spatial correlations corresponding to the molecular length L. In X-ray studies this is manifested as diffuse peaks along the average direction of the molecular long axis at Q = 2π/L and weaker harmonics at 2Q and 3Q wave numbers. This is the case for the recently discovered ferroelectric nematic (N_F) liquid crystals as well. Here we synthesized highly polar three ring rod-shaped compounds with a terminal thiophene ring which on cooling from the isotropic fluid directly transition to the N_F phase that shows the strongest spatial correlations corresponding to 1/3 of the molecular length (L/3). The set of thiophene compounds reported here have ferroelectric polarizations about 20% larger than that of usual ferroelectric nematic liquid crystal materials. This is the result of the tighter molecular packing and larger mass density, due to the lack of flexible terminal chains of these thiophene compounds compared to most of the N_F materials. Below the N_F phase, compounds with a single nitro or two cyano polar groups on the terminal benzene ring exhibit a so far never observed smectic phase with periodicity ∼1/3 the molecular length. Based on our experimental results, we propose a model of this phase featuring antipolar packing of the molecules within the layers.

The photocatalytic production of hydrogen peroxide (H₂O₂) using particulate photocatalysts is a safe, sustainable and green process that requires only oxygen and water as feedstocks and solar energy as a power source. Surface engineering on particulate photocatalysts can significantly improve the performance of photocatalytic H₂O₂ production by optimizing light absorption, surface charge separation, and reaction pathways. To provide a comprehensive and systematic illustration of this topic, various surface engineering strategies are classified and elaborated in this review, which are mainly included in the following two aspects. The first one involves surface modification relating to crystal facets, surface vacancies, and surface functional groups. The second one focuses on surface composite strategies, including combination with metals, semiconductors, carbon nanomaterials, polyoxometalates or their derivatives, and organic compounds. Finally, the challenges and prospects in the surface engineering strategies for particulate photocatalysts for promoting photocatalytic H₂O₂ production are analyzed and discussed.

Polyethylene waste was oxidatively converted into hydroxyl-terminated telechelic macromolecules with controlled molecular weights, which were further reconstructed into sustainable materials with enhanced strength, processability, degradability/recyclability, and filler compatibility through dynamic cross-linking. This strategy enables efficient upcycling of PE into sustainable, high-performance polymers, addressing plastic pollution and advancing circular materials.

Tactile sensors utilizing functional materials decode surface textures for object recognition. Herein, we engineer a donor-acceptor fluorescent material, MNIMP, that synergizes aggregation-induced emission (AIE) and twisted intramolecular charge transfer (TICT) mechanisms. Contact-induced nanoflake assembly on the MNIMP film triggers fluorescence amplification mediated by the combined AIE and TICT effects, through which the surface morphology of textured objects can be accurately visualized as fluorescent patterns. MNIMP maps micro-textures of materials such as rubber, fabrics, and elastic polymers under tactile pressure with kPa-level sensitivity, seamlessly integrating visual and tactile perceptions. These fluorescent signatures can be recognized using a deep-learning model with >98% accuracy. Hardware integration with the embedded algorithm model creates an intelligent tactile sensor system performing concurrent contact imaging, data analysis, and classification. This intelligent platform demonstrates micron-scale resolution and cost-effective manufacturability while maintaining high signal fidelity across diverse target objects.

Visualization of proteins and nucleic acids with super-resolution is a persistent need. Expansion microscopy (ExM) permits nanoscale imaging of biomolecules on a conventional microscope by physically expanding biological specimens embedded in a stretchable hydrogel. However, achieving simultaneous super-resolution co-imaging of proteins and nucleic acids on ExM has remained a general challenge. Here, we present photoclick dual anchoring expansion microscopy (Phan-ExM), which employs an unorthodox anchoring reagent, N-(3-methacrylamidopropyl)-3-(2-methyl-1H-pyrrol-1-yl)-2H-tetrazole-2-carboxamide (MAP-mPyTC), for the rapid and concurrent retention of proteins and nucleic acids within the ExM gel matrix through photoclick chemistry. We demonstrated that MAP-mPyTC could anchor both protein and mRNA biomolecules within 10 min, significantly reducing the time compared to typical ExM techniques, which usually take from several hours to overnight. Moreover, we showed that Phan-ExM significantly enhanced the fluorescence intensity of protein and RNA spots compared to previous methods. With Phan-ExM, we achieved high-resolution co-imaging of multiplex proteins and nucleic acids on a single specimen at ∼85 nm resolution. We revealed that paclitaxel and colchicine treatment significantly disrupted mitochondrial dynamics in BALB/c3T3 cells, with an associated aggregation of ACTB mRNA observed at sites of mitochondrial damage. Phan-ExM is a platform technique that enables super-resolution co-localization of nucleic acids and proteins on the same specimen using a conventional microscope.