Nano Research最新文献

Lithium-sulfur (Li-S) batteries hold the potential to revolutionize energy storage due to the high theoretical capacity and energy density. However, the commercialization process is seriously hindered by the rapid capacity decay and low utilization of sulfur, caused by the inevitable slow dynamics and the “shuttle effect”. The incorporation of metal-based electrocatalysts into sulfur cathodes shows promise in promoting the conversion of lithium polysulfides (LiPSs), reducing the “shuttle effect”, and enhancing cell kinetics and cycle life. Among these, Fe-based materials, characterized by environmental friendliness, low cost, abundant reserves, and high activity, are extensively used in sulfur cathode modification. This article reviews the advancements of Fe-based materials in enhancing Li-S batteries in recent years. Starting from single/multi-component Fe-based metal compounds and single/bimetallic atoms, the influence of different Fe coordination environments on the conversion mechanism of LiPSs is analyzed. It is hoped that this review and the proposed prospects can further stimulate the development and application of the Fe element in Li-S batteries in the future.

Electrical modulation of luminescence is significant to modern light-emitting devices. Monolayer transition metal dichalcogenides are emerging direct-bandgap luminescent materials with unique excitonic properties, and the multiple exciton complexes provide new opportunities to modulate the property of luminescence in atomically thin semiconductors. Here, we report an electrical control of exciton emission in the oscillator strength and spatial distribution of excitons in a monolayer WS₂. Effective modulation of excitonic emission intensity with a degree of modulation of ~ 92% has been demonstrated by an electric field at room temperature. The spatial carrier redistribution tuned by a lateral electric field results in distinct excitonic emission patterns by design. The modulation approach to exciton oscillator strength and distribution provides an efficient way to investigate the exciton diffusion dynamics and to construct electrically tunable optoelectronic devices.

Iron–nitrogen–carbon single-atom catalysts (Fe–N–C SACs) are widely acknowledged for their effective oxygen reduction activity, however, their activity requires further enhancement. Meanwhile, additional structural optimization is necessary to enhance mass transport and achieve higher power density in practical applications. Herein, using ZIF-8 as a template, we synthesized yolk–shell catalysts featuring complex sites of Fe single atoms and Cu nanoclusters (y-FeCu/NC) via partial etching and liquid-phase loading. The synthesized y-FeCu/NC catalyst exhibits high specific surface area and mesoporous volume. Combined with the advantages of highly active sites and yolk–shell structure, the y-FeCu/NC catalyst demonstrated outstanding catalytic performance in the oxygen reduction reaction, achieving a half-wave potential (E_1/2) of 0.97 V in 0.1 M KOH. As a practical energy device, Zn-air battery (ZAB) assembled with y-FeCu/NC catalyst achieved a remarkable power density of 356.3 mW·cm⁻², representing an improvement of approximately 28.5% compared to its solid FeCu/NC counterpart. Furthermore, it showcased impressive stability, surpassing all control samples.

Covalent triazine frameworks (CTFs) are a class of unique two-dimensional nitrogen-rich triazine framework with adjustable chemical and electronic structures, rich porosity, good stability and excellent semiconductivity, which enable great various applications in efficient gas/molecular adsorption and separation, energy storage and conversion, especially photo- and electro-catalysis. Different synthesis strategies strongly affect the morphology of CTFs and play an important role in their structure and properties. In this concept, we provide a comprehensive and systematic review of the synthesis methods such as ionothermal synthesis, phosphorus pentoxide catalytic method, polycondensation and ultra-strong acid catalyzed method, and applications of CTFs in photo- and electro-catalysis. Finally we offer some insights into the future development progress of CTFs materials for catalytic applications.

As a new water treatment technology, Fenton-like reaction has great potential. In this study, we successfully prepared an excellent Fenton-like catalyst, which is composed of cobalt monoatoms and asymmetric subnanoclusters (labeled CoSA/Clu-C₂N), and exhibits excellent peroxymonosulfate (PMS) activation reactivity. By directly comparing the catalytic properties of CoSA-C₂N and CoSA/Clu-C₂N, the synergistic effects of coasymmetric Co subclusters and Co atoms on the activation of PMS and degradation of organic micropollutants were investigated. The results showed that CoSA/Clu-C₂N had higher degradation rates of carbamazepine (CBZ), antipyrine (AT) and chlorobenzoic acid (CA) when combined with active oxidant PMS. The cyclic frequency of CBZ was 5.4 min⁻¹, which was twice as high as the catalytic constant of CoSA-C₂N (2.4 min⁻¹). The results show that CoSA/Clu-C₂N cobalt subnanoclusters and cobalt single atom can synergistically improve the catalytic performance of activated PMS oxidation of micropollutants in water. In addition, electron paramagnetic resonance (EPR) technology has proved that the introduction of Co subnano clusters in CoSA/Clu-C₂N is conducive to the production of singlet oxygen (¹O₂), thereby improving the efficiency of pollutant oxidation. This work lays a solid foundation for the future design of advanced multifunctional catalysts by carefully regulating and combining monmetallic atoms and metal subnanoclusters.

Optical materials with circularly polarized luminescence (CPL) features have attracted a growing interest due to their crucial role in biological sensing, display, spintronics, information storage, and so forth. However, CPL emissions in hybrid nanoparticle systems, in particular, chirality transfer induced CPL from chiral plasmonic nanoparticles, have rarely been explored due to a lack of effective bottom-up synthesis method. Herein, we creatively take advantage of the newly introduced chiral plasmonic nanoparticles-gold nanohelicoid (GNH) to excite the CPL of achiral Rhodamine 6G (R6G). The fabricated GNH@R6G-SiO₂ shows obvious CPL signals with ∣g_lum∣ up to 0.014. Compared with the single GNH, the photoluminescence (PL) dissymmetry factor of the single GNH@R6G-SiO₂ is similar, but with 25 folds higher PL intensities under different circular polarization. Our research not only offers an effective and feasible method to fabricate single-particle level CPL-active materials, but also provides guidelines on how to regulate the CPL of achiral luminophores from chiral plasmonic nanostructures, thereby enlarging the category and quantity of CPL-active materials that can be applied for photonic technologies and visualization biosensing, especially some intracellular chirality related detection.

With the continuous tightening of automotive emission regulations and the increasing promotion of energy-efficient hybrid vehicles, new challenges have arisen for the low-temperature performance of three-way catalysts (TWCs). To guide the design of next-generation TWCs, it is essential to further develop our understanding of the relationships between microstructure and catalytic performance. Here, Rh/CeO₂–ZrO₂ catalysts were synthesized with different Rh metal dispersion by using a combination of the wet impregnation method and reduction treatment. These catalysts included Rh single-atom catalysts, cluster catalysts, and nanoparticle catalysts. The results showed that the Rh nanoparticle catalyst, with an average size of 1.9 nm, exhibited superior three-way catalytic performance compared to the other catalysts. Based on the catalytic activity in a series of simple reaction atmospheres such as CO + O₂, NO + CO, and hydrocarbons (HCs) + O₂ and operando infrared spectroscopy, we found that metallic Rh sites on Rh nanoparticles are the key factor responsible for the low-temperature catalytic performance.

To improve the synergistic effect between dielectric and magnetic loss is a practical and effective way in optimizing electromagnetic wave absorbing materials. The composites of metal particles and carbon ligands derived from metal organic frameworks have gained wide attention. In this study, Co particles and multiwalled carbon nanotubes (CNT) were successfully synthesized covering the surface of silicon carbide (SiC) fibers, and the morphology, interfaces and electromagnetic wave absorption performance were explored. For sample SiC@Co/CNT, the minimum reflection loss value can reach -70.22 dB at 11.21 GHz with the thickness of 2.12 mm. The effective absorbing bandwidth can reach up to 6.03 GHz with the thickness of 1.71 mm, which covers the entire Ku band. It brings more interfaces between Co particles and CNTs as well as SiC fibers and Co/C nanosheets. The interfacial polarization has been hugely enhanced, and the microwave absorbing properties have been improved. This article reports on the impedance matching of magnetic and non-magnetic components and the heterointerface engineering, which can be effective strategy and inspiration to illustrate the relationship between components, structures and functions of electromagnetic wave absorbing materials.

Despite sufficient studies performed in non-primate animal models, there exists scanty information obtained from pilot trials in non-human primate animal models, severely hindering nanomaterials moving from basic research into clinical practice. We herein present a pioneering demonstration of nanomaterials based optical imaging-guided surgical operation by using macaques as a typical kind of non-human primate-animal models. Typically, taking advantages of strong and stable fluorescence of the small-sized (diameter: ~ 5 nm) silicon-based nanoparticles (SiNPs), lymphatic drainage patterns can be vividly visualized in a real-time manner, and lymph nodes (LN) are able to be sensitively detected and precisely excised from small animal models (e.g., rats and rabbits) to non-human primate animal models (e.g., cynomolgus macaque (Macaca fascicularis) and rhesus macaque (Macaca mulatta)). Compared to clinically used invisible near-infrared (NIR) lymphatic tracers (i.e., indocyanine green (ICG); etc.), we fully indicate that the SiNPs feature unique advantages for naked-eye visible fluorescence-guided surgical operation in long-term manners. Thorough toxicological analysis in macaque models further provides confirming evidence of favorable biocompatibility of the SiNPs probes. We expect that our findings would facilitate the translation of nanomaterials from the laboratory to the clinic, especially in the field of cancer treatment.

Activated fibroblasts are major mediators of pulmonary fibrosis. Fibroblasts are generally found in the connective tissue but upon activation can generate excess extracellular matrix (ECM) in the lung interstitial section. Therefore, fibroblasts are one of the most targeted cells for treating idiopathic pulmonary fibrosis (IPF). Here, we develop an anti-fibrotic platform that can modulate both the lysophosphatidic acid receptor 1 (LPA₁) and the inflammatory pathway through tumor necrosis factor α-induced protein 3 (TNFAIP3, also known as A20) in fibroblasts. First, we synthesized a series of LPA₁ antagonists, AM095 and AM966, derived amino lipids (LA lipids) which were formulated into LA-lipid nanoparticles (LA-LNPs) encapsulating mRNA. Specifically, LA5-LNPs, with AM966 head group and biodegradable acetal lipid tails, showed efficient A20 mRNA delivery to lung fibroblasts in vitro (80.2% ± 1.5%) and ex vivo (17.2% ± 0.4%). When treated to primary mouse lung fibroblasts (MLF), this formulation inhibited fibroblast migration and collagen production, thereby slowing the progression of IPF. Overall, LA5-LNPs encapsulated with A20 mRNA is a novel platform offering a potential approach to regulate fibroblast activation for the treatment of IPF.