Materials Today最新文献

Li-metal anode (LMA) has attracted significant attention as a prospective anode material for next-generation Li-metal batteries (LMBs). However, the development of LMBs is hampered by safety concerns, including the risk of short-circuiting, fire, and explosions. These safety issues derive mostly from undesirable reactions of the LMA during cycling, such as dendrite growth, dead Li formation, and volume changes. In response to these challenges, molecular brushes, characterized by their well-defined architecture and multifunction integration, have emerged as a valuable solution to stabilize LMA. This comprehensive review focuses on the design and application of molecular brushes in the field of LMBs, aiming to unveil their structure–function relationship and their pivotal role in enhancing stability of LMA. Moreover, we provide an overview of recent computational studies that have elucidated the conformation and dynamics of molecular brushes in LMBs. Finally, we discuss existing challenges and present future prospects with the goal of motivating the progress of high-performance LMBs.

Printed optoelectronics are paramount in emerging research due to their cost-effectiveness, flexibility, and compatibility with diverse substrates, offering innovative solutions for efficient light manipulation and energy conversion. The pursuit of printed optoelectronics is driven by its potential to overcome challenges in traditional optoelectronics, fostering advancements in areas such as wearable devices, the Internet of Things (IoT), and renewable energy technologies. Two-dimensional transition metal dichalcogenides (2D-TMDs) are promising for emerging research in printed optoelectronics because of their unique optical, electrical, and mechanical properties. By harnessing the exceptional properties of 2D-TMDs, such as high surface area, excellent charge carrier mobility, and tunable bandgaps, in printed optoelectronics, researchers unlock cost-effective and flexible avenues for efficient light manipulation, making these materials pivotal for advancing the field and addressing current optoelectronic challenges. The synthesis of 2D-TMD inks and their integration into printed devices offer a promising paradigm shift, enticing explosive interest with the potential for enhanced performance, scalability, and diverse applications in the dynamic landscape of printed optoelectronics. However, the prominent research advances in terms of optoelectronics, light-matter solid interactions, and printable optoelectronic inks based on 2D TMD materials have not been systematically reviewed. This review focuses on synthesizing and optimizing 2D-TMD inks, exploring their varied applications in printed optoelectronic devices, and paving the way for transformative advancements in this field. This review summarizes the latest research developments in this rapidly evolving area and emphasizes the crucial role of 2D-TMD inks in advancing printed optoelectronics, exploring their unique properties and potential for novel device architectures. The comprehensive outlook in this review proposes a roadmap for ongoing and future research endeavors in the ever-evolving field of printed optoelectronics.

Lithium (Li) metal battery is regarded as a high-energy-density battery system beyond Li-ion battery. However, the cycle life of Li metal batteries with liquid electrolytes is severely hindered by the high reactivity and non-uniform plating/stripping behaviors of Li metal anodes. The plating/stripping behaviors of Li metal anodes are mainly dictated by the transport mechanism of Li ions in solid electrolyte interphase (SEI), a nanoscale passivation film between the anode and electrolytes. SEI is composed of various inorganic and organic components and has a diversiform structure, which complicates the transport behaviors of Li ions in it and differentiates the Li-ion transport mechanism in SEI from that in common liquid and solid electrolytes. Therefore, understanding the transport mechanism of Li ions in SEI is imperative for rationally regulating SEI components and structure and enabling uniform Li plating/stripping behaviors. In this review, the recent progress in understanding the Li-ion transport mechanism in SEI in Li metal batteries with liquid electrolytes is summarized, including the detailed transport mechanisms of Li ions in SEI, and the methods to investigate and regulate the Li-ion transport mechanism in SEI. In particular, an insightful outlook is provided to guide future research on investigating the transport mechanism of Li ions in SEI.

Smart hydrogels based on supramolecular crosslinkers have attracted considerable attentions in recent years owing to their unique dynamic feature and promising properties. How to control the microstructure and macro functions on time dimension, still remains challenge for artificial hydrogels while this is common for natural materials. Here, a supramolecular hydrogel with spatially and temporally controllable modulus and optical properties is developed by in-situ polymerization of acrylamide and host–guest complexes. The guest 1 consisting of electron-poor viologen unit and electron-rich biphenyl unit formed strong 2:2 supramolecular complexes with CB[8] of high binding constant, which provided an efficient supramolecular crosslinkers for hydrogel. Moreover, the hydrogel properties can be tailored on time dimension through controlling supramolecular complexes by introducing Na₂S₂O₄ (SDT) and oxygen to construct a chemical reaction network, resulting in spontaneous gel-sol transition and color change from yellow to dark green. Taking advantage of this feature, an information self-erasing material with controllable lifetime and good rewritability is developed. The lifetime of information can be programmed by adjusting the concentration of SDT, and write-erase process can be repeated at least 16 times. This study provides new insight to develop supramolecular host–guest complexes-based hydrogel with time-dynamic feature.

Despite great success of chimeric antigen receptor T (CAR-T) cells in hematological cancers, the efficacy in solid tumors is extremely restricted. Transforming growth factor-β (TGF-β) and hypoxia are key processes in the development of solid tumors, including the formation of neo-vasculature, dense extracellular matrix (ECM), and immunosuppression. TGF-β inhibition and hypoxia alleviation may be promising approaches to enhance activity of CAR-T cells in solid tumors. Therefore, a self-reinforcing nano-spearhead (BM/LP_siTGF-β NPs) is developed to collaboratively remodel tumor microenvironment (TME) through albumin-mediated tumor targeted delivery of TGF-β siRNA and the nano enzyme MnO₂. BM/LP_siTGF-β NPs efficiently eliminates ECM by down-regulation of TGF-β. Additionally, BM/LP_siTGF-β NPs also produces abundant O₂ and down-regulates HIF-α, leading to normalized vasculature and improved tumor immunosuppression. More importantly, the ECM degradation induced by BM/LP_siTGF-β NPs forms a self-reinforcing loop, further promoting greater tumor penetration of BM/LP_siTGF-β NPs and CAR-T cells. Due to robust TME remodeling capacity of BM/LP_siTGF-β NPs, the therapeutic efficacy of Mesothelin (MSLN) CAR-T cells against triple negative breast cancer (TNBC) are enhanced both in vitro and in vivo. This nano-spearhead provides a good regimen for potent TME remodeling and gives rise to enhanced CAR-T cell efficacy in TNBC treatment.

Electrochemical nitrate reduction reaction (NO₃RR) has been regarded as a promising alternative to the Haber-Bosch process for sustainable and clean NH₃ production. To develop highly active and stable electrocatalysts for NO₃^– to NH₃ production, Cu-based materials have been considered as potential candidates owing to the excellent NO₃^– adsorption to easily overcome the rate determining step of nitrate to nitrite conversion in NO₃RR, although the poor NH₃ yield rate is still challenging. In this study, we report a hybrid electrocatalyst with Bi dopant substitutionally incorporated on cuboctahedra Cu₂O platform (Bi/Cu₂O) via in-situ hydrothermal method. The Bi/Cu₂O shows the NH₃ yield rate of 2562.56 μg h⁻¹ mg_cat^-1 and Faradaic efficiency of 99.2 % at −0.8 V versus reversible hydrogen electrode in a neutral electrolyte, which is the highest performance among previously reported Cu-based electrocatalyst for NO₃RR to NH₃. The interfacial synergetic effect of sufficient protonation from Bi-doped overlayer and efficient NO₃^– adsorption from the Cu₂O platform results in excellent NO₃RR performance. The experimental variable investigations with in-situ attenuated total reflectance-Fourier transform infrared measurement elucidate that not only nitrate to nitrite conversion but also the protonation of *NO₂ is the rate limiting step for NH₃ production.

Due to their superior safety and stability, solid-state electrolytes (SSEs) are a promising alternative to flammable liquid electrolytes in lithium-ion batteries. However, the poor solid–solid contact at the SSEs/electrodes interface remains a significant challenge. To address this issue, inspired by spider silk, we develop a composite polymer electrolyte (SPLZO), which is highly adhesive due to the designed rich hydrogel bond network, containing a supramolecular poly (urethane-urea) (SPU), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and Li_6.5La₃Zr_1.5Ta_0.5O₁₂. The abundant hydrogen bonds mainly enabled inherently strong adhesion to ensure intimate electrolyte–electrode contact with low interfacial impedance. Besides, the soft polymer segments facilitate Li⁺ transport, and the hard components enhance the LiTFSI dissociation and accelerate Li⁺ motion, resulting in a high ionic conductivity of 1.67 × 10⁻⁴ S cm⁻¹. The significantly improved interface contact and high ionic conductivity lead to a decent capacity and cycling performance of the fabricated solid-state lithium-ion batteries. Moreover, the designed SPLZO electrolyte exhibits remarkable deformability, and the flexible lithium-ion battery demonstrates outstanding mechanical flexibility and stability with negligible capacity loss when subjected to various dynamic deformations. This adhesive SSE design strategy opens new possibilities for promoting interfaces in solid-state batteries.

Two-dimensional transition metal carbides/nitrides (MXenes) hold significant promise across diverse domains such as energy, catalysis, environmental science, and life sciences due to their distinct physical and chemical properties. This review focuses on the utilization of Ti-based MXenes specifically for photocatalytic applications. It critically evaluates the structural properties, fabrication strategies, and theoretical simulations of Ti-based MXenes tailored for photocatalysis. Firstly, the structural, electronic and optical properties of Ti-based MXenes are highlighted. Secondly, this review compares the merits and demerits of different fabrication techniques, offering a broad overview of fabrication methods for Ti-based MXenes. Afterwards, strategies aimed at enhancing photocatalytic performance, including interface engineering, defect introduction, heteroatom doping, and morphology control, are summarized. Then this review encapsulates the first-principles calculations and in-situ characterizations related to the fabrication process and photocatalytic mechanism of Ti-based MXenes. Furthermore, it extensively explores the emerging applications of Ti-based MXenes in energy, environmental remediation, and biomedicine. Forward-looking perspectives and insights are finally provided to stimulate innovative ideas and research methodologies for the design, synthesis, and integration of Ti-based MXenes into photocatalytic systems.

Despite development in nanozymes for cancer treatment, challenges in their synthesis and structural optimization for peak catalytic activity persist. A multifunctional enzyme-like nanoparticle using a controllable synthesis that offers a clear structure–activity relationship was developed. The nitrogen-doped mesoporous carbon nanospheres (MCNs) with iron coordination were produced via an in-situ iron-catalyzed pyrolysis, which allowed for precise adjustment of iron content. Not only do Fe/MCN exhibit high graphitization for enhanced photothermal conversion but also feature co-doping with both single atoms and atom clusters, enhancing their enzyme-like activities. These activities included oxidase, peroxidase, catalase, and glutathione oxidase, leading to synergistic effects in chemodynamic, photodynamic therapies, and hypoxia alleviation. Additionally, Fe/N-MCNs induced potent immunogenic cell death, aided by ROS, ferroptosis, and ferroptosis-sensitized photothermal therapy. Fe/N-MCN also provided excellent photoacoustic and magnetic resonance imaging capabilities, establishing a multifaceted platform for the treatment of breast cancer and the inhibition of postoperative recurrence and metastasis.

In response to the critical need for lightweight designs and carbon neutrality, we introduce an innovative additively manufactured ultrafine-grained Al-Mg-Mn-Sc-Zr alloy reinforced with nano-structured planar defects via laser powder bed fusion (L-PBF), developed for complex-shaped parts that demand high strength and superior ductility. Owing to the uneven distribution of the L1₂-ordered Al₃(Sc, Zr) nanoparticles, the as-printed alloy demonstrates a hierarchically heterogeneous microstructure featuring a triple-modal grain distribution. Tailored planar defects comprising stacking faults, 9R phase and nanotwins are strategically introduced in the as-printed alloy. Beyond the nano-scaled planar defects and the triple-modal grain distribution, further direct ageing process augments the abundance of nanoprecipitates, collectively boosting the yield strength to 656 MPa, which is higher than almost all L-PBFed Al alloys hitherto reported, and a decent ductility of 7.2 %. This work paves the way for the near net shape forming of high-performance Al alloy components for advanced structural applications.