Materials Today最新文献

With the merits of inherent physicochemical properties of hollow structure, high mechanical strength, thermal stability, ultrahigh light absorption capacity, and ultrahigh thermal conductivity, carbon nanotubes (CNTs) are extensively used to enhance the thermal storage capabilities of solid–liquid phase change materials (PCMs). Interestingly, CNTs can act as thermally conductive additives and supporting skeletons when marring with PCMs. The state-of-the-art reviews on PCMs pay attention to carbon-based porous composite PCMs or nanoparticle dispersed PCMs, CNTs-derived PCMs only share a small part, lacking of a comprehensive review for multifunctional CNTs compounded PCMs. Herein, focusing on the enhancement effects of CNTs on PCMs, we retrospectively describe composite PCMs with a novel category way, by using CNTs as nanoadditives, porous supporters, and secondary network. We emphasize the micro-mechanism of heterogeneous interactions induced by CNTs: crystallization behavior, interfacial thermal resistance, thermal conductivity, phonon transport. Simultaneously, we provide in-depth insight into relationship between micro structural and thermal properties of CNT-derived PCMs. As a result, some different pathways of modern utilization based on the improved PCMs are presented. Finally, we outline the current challenges of designing CNTs to enable advanced functional thermal storage materials. The review aims to inspire clever use of CNTs into PCMs for targeted applications.

Wearable electronic devices find increasing applications in mobile medical sensing and monitoring, human–computer interaction, and portable energy collection and storage, owing to their flexibility and stretchability. In recent years, transition metal nitrides and carbides, known as MXenes, have become cornerstones for the preparation of novel flexible electronic devices because of their excellent electrical conductivities, abundant surface functional groups, and large specific surface areas. This review presents the latest developments in MXene-based wearable electronic products, including hydrogels, paper, composite materials, and self-powered devices. These products can be integrated with artificial intelligence to show unique applications in healthcare, inspection, and control of human-like machines. The application prospects of MXenes in the new generation of wearable electronic devices are forecast, the challenges and difficulties in designing MXene-based wearable electronic devices are discussed, and corresponding solutions are suggested. This review also provides future research directions for the development of MXenes for pliable and wearable applications.

Circularly polarized luminescence (CPL) is an intriguing phenomenon characterized by the production of distinct emissions by chiral compounds when exposed to left- and right-handed circularly polarized luminescence. This phenomenon, distinguished by its ability to convey more intricate information and overcome angle dependence limitations associated with natural light, is progressively demonstrating its merits in diverse applications such as 3D optical displays, optical bio-probes, quantum communication, and asymmetric synthesis. The predominant focus of the current report centers on CPL materials within the visible region. However, it is noteworthy that Near-Infrared (NIR) emitters manifesting CPL characteristics hold substantial promise in diverse applications such as biological imaging, night vision, and organic light-emitting diodes. To address this, the present review systematically encapsulates research endeavors concerning NIR-CPL materials over last decades, systematically categorizing them into metal complexes and small organic molecule sections. Emphasis is placed on the exploration of extended emission wavelengths and the CPL performance exhibited by various classical molecular structures in the NIR spectrum. Furthermore, the review delves into methodologies aimed at enhancing CPL signals within the NIR emission region.

Developing dopants and hosts is essential for enhancing the performance of blue phosphorescent organic light-emitting diodes (PhOLEDs). Herein, we developed host materials with thermally activated delayed fluorescence (TADF) characteristics—specifically, 9-(12-(3-(triphenylsilyl)phenyl)-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracen-11-yl)-9H-carbazole (BO-Cz-Si-1) and 9-(10-(3-(triphenylsilyl)phenyl)-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracen-11-yl)-9H-carbazole (BO-Cz-Si-2). These materials, derived from boron- and oxygen-based 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene (DOBNA), are designed with TADF properties through a sterically modulated structure featuring one carbazole unit and one tetraphenylsilyl unit attached to the DOBNA core. These hosts exhibit a high triplet energy of 3.0 eV along with TADF characteristics, ensuring high efficiency and prolonged operational stability in blue PhOLEDs. The combination of BO-Cz-Si-1 (an electron transport-type host) and 9-(3-(triphenylsilyl)phenyl)-9H-3,9′-bicarbazole (a hole transport-type host) as a mixed host yields a maximum external quantum efficiency of 23.5 %, blue CIE color coordinates of (0.13, 0.18), and an improved device lifetime compared to the triazine-derived host. Notably, the DOBNA-derived hosts exhibit significantly longer device lifetimes than the triazine-derived host, irrespective of whether Ir or Pt phosphor is doped into the devices, suggesting the universal applicability of DOBNA-derived hosts for blue phosphors. These findings underscore the promising potential of DOBNA-based TADF hosts as n-type hosts, paving the way for highly stable and efficient blue PhOLEDs.

The provision of green hydrogen on an industrial scale is one of the challenges for a successful CO₂-neutral energy transition. Sintering is still the bottleneck for the use of iron-based oxygen carriers for efficient hydrogen production and storing performance in chemical looping in a large-scale system. In this work, we demonstrate an effective way for hydrogen production by the synthesis of structured oxygen carriers (OC) from cost efficient, green and environment-friendly materials. The novel structured oxygen carriers with a core–shell architecture show an innovative concept to prevent the agglomeration of pellets in the fixed bed reactor system. The environment-friendly iron-based material maintained an oxygen exchange capacity of over 80 % for 100 cycles. The pore network of the catalytic system was preserved by incorporating a structure with separate compartments. A synergistic effect between the sintering, especially of the porous network, and the gas transport was revealed. In addition, an undiscovered leach-out effect of the OC system on the Al₂O₃ support material, which is associated with a deactivation phenomenon, was also revealed. The work provides fundamental new insights for understanding the phenomena that occur during the sintering process in the OC material and the influence on the lifetime of the chemical looping process. Finally, we present that the structured OC exhibits excellent performance and provides a new approach in material design for successful implementation in high temperature catalytic fixed bed system for long term operation.

$\alpha$-Sn is an elemental topological material, whose topological phases can be tuned by strain and magnetic field. Such tunability offers a substantial potential for topological electronics. However, InSb substrates, commonly used to stabilize $\alpha$-Sn allotrope, suffer from parallel conduction, restricting transport investigations and potential applications. Here, the successful MBE growth of high-quality $\alpha$-Sn layers on insulating, hybrid (001) CdTe/GaAs substrates, with bulk electron mobility approaching 20000 cm²V⁻¹s⁻¹ is reported. The electronic properties of the samples are systematically investigated by independent complementary techniques, enabling thorough characterization of the 3D Dirac (DSM) and Weyl (WSM) semimetal phases induced by the strains and magnetic field, respectively. Magneto-optical experiments, corroborated with band structure modelling, provide an exhaustive description of the bulk states in the DSM phase. The modelled electronic structure is directly observed in angle-resolved photoemission spectroscopy, which reveals linearly dispersing bands near the Fermi level. The first detailed study of negative longitudinal magnetoresistance relates this effect to the chiral anomaly and, consequently, to the presence of WSM. Observation of the $\pi$ Berry phase in Shubnikov-de Haas oscillations agrees with the topologically non-trivial nature of the investigated samples. Our findings establish $\alpha$-Sn as an attractive topological material for exploring relativistic physics and future applications.

The poor interface compatibility and adverse safety concerns are enormous challenges for fabricating high temperature adaptative potassium ion batteries (PIBs) and beyond. To present, various protocols have been developed to enhance the thermal protection capacity, nevertheless, the one-time protection rather than the reversible protection or retarded thermal protection (above 120 °C) cause serious threaten for safety issues. Herein, (E)-4,4′-((diazene-1,2-diylbis(4,1-phenylene))bis(azanediyl))bis(4-oxobutanoic acid) (OBA) grafted BiSbS₃ nanorods embedded into porous N-P co-doped carbon sheets (NPC), i.e. BiSbS₃/NPC-OBA with an excellent interface compatibility was designed serving as the state-of-the-art thermorunaway annihibitor toward reversible thermal protection. Both theoretical calculations and experimental trials manifest that such annihibitor undertakes the process of isomerization-polymerization-depolymerization highly driven by trans-to-cis transition, smartly switching-off the ion extrusion/extraction when approaching the thermorunaway temperature and restoring its original properties when cooled to room temperature. The other ingenious merits including fine low-temperature adaptability and long lifespan were also approached in such highly safe energy storage system. The deepened investigations on interface property and reversible thermal protection shed a new perspective on depolymerizable electrode fabrication toward advanced safe energy storage.

Symmetry is a significant concept that has played a fundamental role in various fields of science, including particle physics, condensed matter physics, and materials science. Symmetry has contributed to the advancement of our understanding of phenomena such as the discovery of new particles, spintronics, superconductivity, and the modulation of material properties. The principle of symmetry continues to guide progress and unification across various scientific disciplines. The emergence of low-dimensional materials (LDMs) has significantly expanded the materials landscape, enabling potential for the modulation of their properties through symmetry engineering. This has opened up new avenues for theoretical research and advanced device development. This review summarizes the application of symmetry in different materials systems and highlights the latest research progress in symmetry breaking engineering of LDMs. The benefits of incorporating symmetry principles from physics into materials science are also discussed.

Antifouling coatings play a crucial role in preventing the adhesion of marine organisms, bacteria, and blood, making them a primary strategy for combating biofouling in the marine industry. However, conventional antifouling coatings suffer from drawbacks such as high toxicity, limited abrasion resistance, and unstable polymer degradation rates, which can have adverse effects on the environment, economy, and human health. Thus, there is an urgent need for the development of sustainable and nontoxic antifouling coatings. This review first presents four major antifouling strategies: traditional coatings based on wettability, traditional coatings with protective structures, nontoxic coatings based on main chain degradable polymers, and nontoxic coatings combining main chain degradation with branch chain hydrolysis polymers. Second, the review provides a comprehensive overview of antifouling coatings with diverse functionalities, including antibacterial, anti-protein, anti-blood, anti-incrusting, adhesive, self-healing, and corrosion-resistant properties. Then, the application of antifouling coatings in marine environments and the medical field is thoroughly explored. Additionally, the review addresses the current challenges encountered by antifouling coatings. Finally, a forward-looking perspective is presented, envisioning future advancements in this field. By addressing these aspects, this review aims to stimulate further development and innovation in the realm of antifouling coatings.