Science China Materials最新文献

Brominated butyl rubber (BIIR) is extensively utilized in products such as tyres and biomedical products owing to its excellent elasticity and gas barrier properties, while the recycling of the end-of-life BIIR products remains a challenge because of the existence of a covalent cross-linked network. Herein, direct upcycling of unmodified waste BIIR is achieved through a nanoparticle-mediated interfacial cross-linking strategy, circumventing chemical modification or degradation of its polymer structure. Specifically, pyridyl-functionalized silica nanoparticles (SiO₂-Py) are synthesized and utilized to crosslink the bromine atoms in waste BIIR with those of fresh BIIR to reconstruct the crosslink network without altering the original sulfur-vulcanization network of waste BIIR. The resulting composites exhibit a dual interpenetrating network structure comprising the sulfur-vulcanized network and the bromine-pyridinium crosslinked silica-rich network, which endows the composites with exceptional strength and toughness. As a result, the waste BIIR from the discarded bicycle inner tyres is successfully upcycled into high-performance BIIR composites, demonstrating superior tensile strength (∼14 MPa), toughness (∼60 MJ m⁻³), and ultra-low air permeability (8.78×10⁻¹⁵ cm³ cm/(cm² s Pa)), significantly outperforming the original material from bicycle inner tubes. This work presents a scalable and effective solution for BIIR waste recycling, offering great potential for advancing the sustainable development of the rubber industry.

Luminescent thermometry has become a research hotspot in recent years due to its advantages of high spatial resolution, fast response, and non-invasive nature. However, achieving high-performance temperature imaging requires both luminescent materials with high temperature sensitivity and efficient temperature imaging methods, which remains a significant challenge. In this study, a series of pure-phase rubidium germanate phosphors doped with manganese were synthesized and encapsulated into polydimethylsiloxane (PDMS) films to improve their chemical stability. The dramatic temperature-dependent luminescence behavior of Mn⁴⁺ in the Rb₂Ge₄O₉ matrix provides reliable and efficient methods for temperature sensing. The high-sensitivity temperature sensing capability of the Rb₂Ge₄O₉:0.002 Mn⁴⁺ fluorescent film has been confirmed, leveraging temperature-dependent emission intensity, luminescence decay lifetime, and time-resolved intensity ratio techniques. Notably, Rb₂Ge₄O₉:Mn⁴⁺ fluorescent film exhibits a strikingly high relative sensitivity of 17.03% K⁻¹ at 330 K in the time-resolved thermometry scheme, which is the highest relative temperature sensitivity within the physiological temperature range known to us. High-performance temperature imaging of the fluorescent film is achieved through the time-resolved intensity ratio strategy with a best practical temperature resolution of 0.08 K at 325 K. Furthermore, the temperature images of an operating nickel circuit with a line width of 20 under different working currents were recorded, showing a clear circuit microstructure and temperature gradient. These findings pave a novel path for realizing high-performance temperature imaging.

Driven by rapid advancements in science and technology, public demand for textiles is undergoing a notable shift—moving beyond traditional fundamental functions such as warmth and aesthetics towards intelligent and functional directions. Natural biomass-derived polysaccharides are identified as critical materials for next-gen flexible wearable smart textiles due to their biocompatibility, biodegradability, renewability, and unique chemical structures. Herein, this review presents an overview of some common natural biomass-derived polysaccharide materials for preparing flexible wearable smart textiles. It also introduces the basic structural features of common natural biomass-derived polysaccharides and discusses relevant modification methods. Moreover, current preparation methods of natural biomass-derived polysaccharide materials for flexible wearable smart textiles are systematically summarized, and an in-depth exploration is carried out to dissect their respective advantages and inherent limitations. This review also summarizes the performance characteristics, action mechanisms, and applicable scenarios of flexible wearable smart textiles based on natural polysaccharide materials. Concurrently, it discusses and analyzes the applications of flexible wearable smart textiles based on natural polysaccharide materials in healthcare, motion tracking, smart clothing, and energy storage and management. Finally, existing challenges and potential directions in the field of natural polysaccharide materials-integrated smart textile systems are comprehensively summarized and presented. Overall, such insights are expected to steer the development of more efficient green flexible wearable devices based on these smart textiles.

Organic-inorganic hybrid copper(I) halide semiconductors have attracted extensive attention for applications in phosphor-converted white light-emitting diodes (pc-WLEDs), X-ray imaging, and photodetectors because of their superior photo/radioluminescence, structural diversity, and eco-friendliness. In our previous work, we proposed a novel strategy for synthesizing highly efficient blue-emitting copper(I) halide hybrids by combining coordinated anionic inorganic modules with cationic derivatives. However, the complexity of the synthesis process has limited the practical application of this approach. To address this challenge, we report a facile, efficient, and rapid solution-based ultrasonic treatment method for synthesizing high-performance blue-emitting phosphors with this structural motif using inexpensive and commercially available tetraethylammonium halides (TEAX, X = Cl, Br, and I). The synergistic interplay of ionic and covalent bonds in these compounds endows them with a high photoluminescence quantum yield (PLQY) of 70% and excellent stability. These materials exhibit a thermally activated delayed fluorescence (TADF) mechanism, delivering outstanding performance in pc-WLEDs and X-ray imaging. Their exceptional properties highlight their significant potential for use in optoelectronic devices and X-ray scintillators. This work provides an important reference for the rapid synthesis of high-performance copper(I) halide hybrid phosphors and paves the way for their commercial application.

This study demonstrates a dual-interface engineering approach for performance enhancement in perovskite-silicon tandem solar cells. By applying ethylenediamine dihydroiodide (EDAI₂) to simultaneously modify both top and bottom interfaces of wide-bandgap perovskite layers, we achieve synergistic defect suppression and charge transport optimization. Time-resolved photoluminescence characterization reveals extended carrier lifetimes and improved spatial homogeneity in dual-modified perovskite films. The optimized single-junction wide-bandgap (>1.66 eV) perovskite solar cells attain a champion efficiency of 22.75% with enhanced operational stability. Implemented in perovskite-silicon tandem configuration, the devices achieve over 31% power conversion efficiency, validating the effectiveness of organic ligand-mediated dual-interface engineering in regulating carrier dynamics and advancing perovskite-based tandem photovoltaics.

The oxygen evolution reaction (OER) has become the barrier of the development and application of next-generation sustainable energy systems due to its extremely sluggish reaction kinetics. One of the fundamental challenges is to develop cost-effective and high-efficiency electrocatalysts. Elucidating the dynamic structure evolution of catalysts at electrode-electrolyte interfaces during the reaction is of vital importance for understanding how to activate and sustain electrocatalytic performance. To this end, in situ techniques are invaluable for identifying the active centers together with monitoring the key intermediates under operating conditions. In this review, the latest advances on several cutting-edge in situ methods for characterizing the structure evolution process of OER electrocatalysts are comprehensively summarized. Significantly, a brief overview of active motifs and robust structures during electrocatalysis is provided using multiple in situ correlative techniques, which will contribute to establishing the essential structure-performance relationships and updating the understanding of electrocatalytic mechanisms at unprecedented atomic-scale levels under realistic working conditions. Finally, key challenges and perspectives in this emerging field are highlighted for promoting the design of promising electrocatalysts towards efficient oxygen-associated electrocatalysis and electrosynthesis.

Escalating global climate change has precipitated a dramatic surge in building cooling/heating energy demands, critically undermining urban sustainability. Although dynamic thermal management technologies show potential for reducing architectural carbon footprints, prevailing active regulation systems remain constrained by energy-intensive mode-switching mechanisms and unsustainable operational costs. Here, we develop a zebra-inspired radiative modulator (ZIRM) that achieves climate-customized building thermal management through spatially partitioned integration of radiative cooling (RC) and heating (RH) functional units. The material breakthrough resides in a hybrid thin-film architecture combining a cellulose acetate/Zeolitic imidazolate framework-L (ZIF-L) porous membrane (solar reflectance ∼95%, thermal emissivity ∼0.88) with an MXene/ZIF-67 derived carbon-based absorption layer (solar absorption ∼93%, thermal emissivity ∼0.37), resolving the opto-thermal coupling limitations inherent to conventional materials. Experimental verification demonstrates that programmable regulation of the RC/RH area ratio enables broad-range temperature differential control from −4.3 to 12.1 °C during daytime operation. Building energy simulations reveal ZIRM’s annual energy consumption of 1.45×10¹⁰ GJ, corresponding to 9.9% and 2.7% reductions compared to pure RC and RH systems, respectively. The established “configuration-environment-performance” predictive model pioneers a paradigm-shifting solution for carbon-neutral architecture, synergizing material innovation with climate-customized engineering strategies.

Chromium oxides (CrO_x) and fluorinated graphite (CF_x) are two typical cathode materials for lithium primary batteries. The former owns the highest theoretical energy density, but suffers from poor low practical capacity and inferior rate capability; the latter has the highest theoretical discharge capacity, but fails to fast discharge. It is desirable to combine the merits of the two cathodes by designing a composite cathode. However, the electrochemical performance of the composite cathode is still far from satisfactory. In this work, we identified that by regulating the overlapped discharge potential of these two cathodes, the F atom will migrate from CF_x to CrO_x, thus leading to a homogeneous distribution of LiF and improved ionic and electronic conductivity, eventually enhancing the high-rate discharge performance. Benefiting from the synergetic effect, the CrO_x/10%eCF_x composite exhibits a considerably high energy density of 496.59 Wh kg⁻¹ at a power density of 49.7 kW kg⁻¹ (50 C), which is far superior to the pure CrO_x and CF_x electrodes. We believe that the high-performance CrO_x/eCF_x composite cathode will justify its practical application in revitalizing advanced lithium primary batteries.

Electrochemical potential and ion diffusion of electrode materials restrain the energy and power densities of lithium-ion batteries, and these challenges also remain in the intercalation-type Li₃VO₄ (LVO). In this work, the local [VO₄] coordination symmetry in LVO is broken by a higher concentration of oxygen vacancies (Vö), resulting in an increased average V–O bond length and a larger ligand field splitting. These alterations reduce the energy level of the lowest unoccupied orbitals (e*) and lift the electrochemical potential, resulting in a higher voltage output. Additionally, the broken local symmetry in Vö-LVO is found to reduce the band gap and expand the ion transport channels, which favors enhancing electronic conductivity and facilitates ion diffusion, thereby improving the electrochemical kinetics in the energy storage process. The local symmetry broken sample (Vö-LVO) achieves a significantly improved capacity of 532 mAh/g at 0.1 A/g in comparison with 394 mAh/g of pristine LVO, and long cycling stability with retained capacity of 398 mAh/g at 1 A/g over 500 cycles compared with 236 mAh/g of the pristine LVO. The fundamental understanding paves the way to exploit high-performance electrodes via ligand field engineering for next-generation rechargeable batteries.

Negative stiffness (NS) structures leverage multi-stable mechanisms to demonstrate energy-absorbing capabilities. Nonetheless, existing implementations are impeded by material and manufacturing, which constrain load-bearing capacity, reusability, and energy absorption efficiency. The observed flexural bounce behavior in beam structures offers a promising avenue for achieving multi-stability and reusability. Consequently, we utilize continuous carbon fiber reinforced thermoplastic polymers (CCFRTP) and three-dimensional (3D) printing to fabricate NS structures featuring cosine beam cells, aiming to elucidate the mechanisms through which CCFRTP modulates their multi-stability. Prior to this, a wet twisted method for continuous carbon fiber (CCF) was employed to augment the mechanical properties and elucidate the failure behaviors and interfacial adhesion mechanisms. Building upon this, a one-stroke path planning model was utilized to delve into the bistability principles and energy absorption mechanisms of the CCFRTP cosine beam structure. The displacement-controlled loading and unloading experiments were conducted to assess the energy absorption characteristics of the structure in both energy-locked and repetitive energy absorption modes. Furthermore, a dual-unit assembly structure was fabricated to investigate its overall deformation and energy absorption properties, thereby validating the feasibility of the negative stiffness honeycomb structure. This approach holds promise for aerospace and naval applications requiring efficient energy absorption under large deformation and high loading.