Science China Materials最新文献

Near-infrared (NIR) mechanoluminescent (ML) materials hold significant potential for nondestructive detection and biological stress imaging applications. However, practical implementation may be hindered by a narrow NIR ML bandwidth, dependence on ultraviolet preirradiation, and a high stress threshold. In this study, we develop a low-threshold broadband NIR ML material with self-recoverable characteristics by introducing Cr³⁺ into a simple and naturally abundant oxide host, MgO. The observed ML originates from the localized piezoelectricity effect induced by Cr³⁺ incorporation. The optimized MgO:0.008Cr³⁺ exhibits a predominant ML peak at 809 nm with a broad full width at half maximum of 209 nm. Notably, this material demonstrates high ML intensity and sensitivity, enabling detectable emission even under extremely low-stress conditions (1 N). Leveraging its bright and broadband NIR ML, MgO:Cr³⁺ is applied for nondestructive assessment of wine quality. Furthermore, a simulated biological stress imaging model was used to verify its superior tissue penetration ability. This study expands the library of self-recoverable NIR ML materials with broadband emission and offers valuable insights for advancing the practical utilization of NIR ML technologies.

Transition-metal carbides (TMCs) have emerged as promising alternatives to platinum-based catalysts in the electrocatalytic hydrogen evolution reaction (HER), showcasing substantial potential for sustainable energy applications. Herein, a rapid microwave-plasma-assisted synthesis strategy (60 s) is employed to fabricate phosphorus-doped tungsten carbide (WC) uniformly loaded with osmium (Os) nanoclusters (Os/P-WC). The resulting Os/P-WC catalyst exhibits exceptional HER performance, achieving a benchmark current density of 10 mA cm⁻² with low overpotentials of 20, 51, and 11 mV in alkaline, acidic, and alkaline seawater electrolytes, respectively. Furthermore, it maintains stable operation for 100 h at both 10 and 500 mA cm⁻² in alkaline electrolyte. In-situ Raman spectroscopy, in-situ electrochemical impedance spectroscopy (EIS), and hydrogen binding energy (HBE) experiments confirm that the electronic metal-support interaction (EMSI) generates electron-enriched Os active sites. These sites facilitate the adsorption and dissociation of water, optimize the adsorption and desorption of hydrogen intermediates (H*), and thereby significantly accelerate reaction kinetics. This work presents a novel design and synthesis strategy for developing highly active electrocatalysts with low precious metal loading for H₂ evolution applications.

The dual-responsive targeted photosensitizer (PS) exhibits significantly enhanced selectivity, enabling precise and safety in photodynamic therapy (PDT) for tumor treatment. However, synthetically endowing a single molecule with both targeting functionality and dual-responsive properties is an extremely complex task. Thus, research in this related field is relatively scarce. Herein, we present a novel PS named B-HCPP-RGD, which integrates α_Vβ₃ integrin receptor targeting capabilities with dual responsiveness to both H₂O₂ and cathepsin B. This PS can specifically recognize tumor cells and respond to the overexpressed H₂O₂ and cathepsin B in tumor cells, ultimately releasing type I PS (HCEA) with a high reactive oxygen species (ROS) yield. In vitro studies demonstrated that B-HCPP-RGD exhibits minimal phototoxicity towards normal cells, while showing significant phototoxicity towards tumor cells. Even under hypoxic conditions, B-HCPP-RGD maintains strong phototoxicity towards tumor cells. In vivo studies revealed that B-HCPP-RGD can actively target the tumor and achieve a high tumor inhibition rate. This study establishes a novel approach to enhance the efficacy and precision of PDT for tumor treatment.

H₂O activation plays a pivotal role in steering the activity and selectivity of electrochemical CO₂ reduction reaction (eCO₂RR). However, precisely tuning this process to favor eCO₂RR over the competing hydrogen evolution reaction (HER) remains a formidable challenge. Herein, we report a fluorine-doped La₂CuO₄ (F-LC) catalyst that significantly enhances CO₂ activation, H₂O dissociation and asymmetric C–C coupling by facilitating the hydrogenation of adsorbed CO (*CO) to form *CHO intermediate. The F-sites in F-LC accelerate interfacial H₂O dissociation via hydrogen bonding interactions, generating abundant active hydrogen (*H) species that facilitate the hydrogenation of *CO to *CHO. Moreover, the formation of a dense hydrogen-bond network on the F-LC surface reorganizes interfacial H₂O molecules, enhances proton transfer, and suppresses the competitive HER. These synergistic effects promote effective asymmetric *CO–*CHO coupling, leading to efficient multicarbon (C₂₊) products formation. As a result, F-LC achieves a Faradaic efficiency of up to 73.0% for C₂₊ products, significantly surpassing that of undoped LC (41.7%), thereby highlighting the crucial role of F doping in promoting interfacial H₂O activation and C–C coupling. This work offers a promising strategy to boost eCO₂RR to C₂₊ products by optimizing interfacial H₂O dissociation and enhancing CO₂ activation.

Hydrogel optical fibers have gained widespread use in signal sensing due to their high sensitivity, non-toxic light-sensing capabilities, and rapid responsiveness. However, different stimuli within the body (e.g., compression, temperature changes, and pH variations) can produce similar effects on their sensing signals, making it challenging to decouple these overlapping signals. Herein, we report a programmable hydrogel optical fiber (PHOF) assembled from various hydrogel-based sensors, where structural reconfiguration is enabled by imine bonding. The PHOF was fabricated using a template-assisted method to ensure structural homogeneity among functional units, resulting in a more uniform structure after subsequent assembly and splicing with minimal impact on optical attenuation (optimal light attenuation: 1.54 ± 0.04 dB/cm). By introducing distinct functional phases, we successfully constructed a multi-responsive sensor capable of detecting stress, temperature, and pH. The development of PHOF based on dynamic covalent bonding offers a strategy for designing smart materials and multiplexed sensors with user-defined functions, holding great promise for significant applications in complex signal sensing.

Transparent superhydrophobic coatings hold significant promise for diverse applications but face challenges in balancing optical performance with mechanical robustness. Here, we develop a multifunctional coating by integrating precision-engineered subwavelength nano-cone arrays, UV-curable polyurethane (Norland optical adhesive, NOA) matrices, and a low-friction perfluoropolyether (PFPE) monolayer. Fabricated via nanosphere lithography and nanoimprinting, the coating demonstrates excellent superhydrophobicity (static contact angle: 165°, sliding angle: 2°), and achieves 92% visible-light transmittance, 3% reflection reduction, and a haze as low as 0.4%. Crucially, superhydrophobicity of the coating can be maintained under harsh conditions, including 18,000 abrasion cycles (20 kPa), 24-h high-speed water jets (2 bar), and 45 tape-peeling tests. Finite element analysis reveals that nano-cone geometry minimizes stress concentration, while NOA’s balanced mechanical properties enhance durability. The high flexibility of the coating ensures compatibility with curved surfaces for diverse substrates. This scalable approach overcomes the durability-transparency trade-off, enabling promising applications in self-cleaning optics, solar panels, and flexible electronics.

Achieving optimal electromagnetic properties in composites requires fine-tuning of microstructure and composition, presenting both practical value and fundamental challenges. Through precisely controlled carbonization of polymer-coated Fe₃O₄@SiO₂ assembled units, this work elucidates the phase transition-mediated enhancement of electromagnetic wave absorption properties. Raspberry-like C/Fe₃O₄@SiO₂@DC magnetic microspheres are fabricated through a multi-step process involving bubble-assisted hydrothermal growth, silica coating, phosphonitrile polymerization, resin encapsulation, and controlled carbonization. The controlled carbonization temperature-mediated phase transformation from Fe₃O₄ to Fe₂SiO₄ within the microspheres serves to fine-tune both electromagnetic parameters and impedance matching behavior. The C/Fe₃O₄@Fe₂SiO₄@DC microspheres carbonized at 700°C exhibit exceptional electromagnetic wave absorption performance, attributed to: (i) the heterogeneous interfaces between dual-phase components, and (ii) the synergistic dielectric-magnetic loss mechanism. The optimized composite demonstrates exceptional microwave absorption performance, achieving a minimum reflection loss (RL_min) of −17.86 dB and an effective absorption bandwidth (EAB) of 6.03 GHz (11.5–17.5 GHz) at an optimal thickness of 2.2 mm. The synergistic combination of tailored composition, optimized interfaces, and controlled defects enables unprecedented EM wave attenuation, providing a blueprint for high-efficiency broadband electromagnetic wave absorbing materials.

Scalable printing of stretchable conjugated polymer films offers the opportunity to develop low-cost and large-area wearable electronics. However, achieving optimal film morphology to simultaneously improve energy dissipation and charge transport is still challenging for printed conjugated polymer films. Herein, we fabricate large-area stretchable conjugated polymer films with low crystallinity but strong chain alignment toward a high-performance wearable X-ray detector by simultaneously regulating fluid field and solidification dynamics during bar-coating. The strong fluid field aligns conjugated polymer chains in the coating direction and enhances solution aggregation in the initial wet layer, while sequential rapid solidification of the thin wet layer further restricts polymer crystallization but facilitates the alignment of aggregates, forming highly-aligned nanofiber networks within the elastomer phase. The elastomer-constrained nanofiber networks can further align with strain to maintain connectivity, providing an efficient charge transport channel during stretching. Consequently, the film shows high charge mobilities of 6.11 and 2.98 cm² V⁻¹ s⁻¹ under 0% and 100% strains, among the highest values for stretchable conjugated polymer films. The designed film also exhibits a high sensitivity of 1757.2 µC Gy_air⁻¹ cm⁻² and an ultralow detection limit of 72.5 nGy_air s⁻¹, maintaining good X-ray imaging capability before and after stretching.

Bacterial infections seriously jeopardize human life and health. Photodynamic therapy (PDT), as an emerging noninvasive antibacterial strategy, has proven to be an effective treatment method against bacterial resistance. However, current photosensitizers suffer from inadequate free radical generation and limited functionality. To address this issue, a new π-conjugated viologen derivative, 3TPhDPyMeOTf, was designed. This derivative with multiple thiophene units enhances visible light absorption, and the presence of multiple pyridine structures allows the photosensitizer to generate more free radicals. Experimental and theoretical studies have demonstrated its inhibitory effect on bacterial growth both in vitro and in vivo, demonstrating a broad-spectrum antibacterial effect. The photosensitizer also exhibits excellent bacterial membrane staining, making it suitable for bacterial imaging. The design of this photosensitizer provides a new direction for the development of potent photosensitizers and photodynamic therapy.

Superhydrophobic coatings that physically separate metal substrates from aqueous media have emerged as a promising strategy against metal corrosion; however, their practical application is hindered by poor mechanical durability and rapid performance degradation in the harsh environment. Herein, inspired by the granular architecture and dynamic metal coordination chemistry in mussel byssus cuticle, a hierarchical metal coordination-mediated self-adaptive coating (SC) integrating surface superhydrophobicity, self-healing anticorrosion, and damage-monitoring capacity is constructed on steel substrates using the metal-organic framework (MOF) as the multifunctional nanoplatform. Specifically, a MOF-polydopamine nanocomposite coating is fabricated on mild steel via a coordination-dissociation-polymerization mechanism, where the MOF serves as a self-sacrificial template to initiate the deposition of polydopamine, and the SC is obtained after the subsequent hydrophobization via Michael addition and Schiff base reaction. The super-hydrophobic surface of SC with a water contact angle of 160° provides a superior passive barrier against corrosive media, showing a protective efficiency of 97.5%. Furthermore, the MOF-polydopamine interlayer endows the SC with superior corrosion-triggered self-healing properties by forming protective adsorption films at the exposed steel surface, thereby preventing rapid failure of the SC caused by mechanical damage. Additionally, the photothermal properties of the polydopamine moieties generate a rapid temperature gradient upon light exposure, allowing early-stage damage detection through infrared thermography. This work presents a biomimetic strategy for developing intelligent anticorrosion coatings that combine superhydrophobicity, self-repair, and realtime damage sensing, advancing the application of MOF-derived materials in protective coatings.