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The interplay between eigenvalue discreteness and eigenstate localization is a fundamental characteristic of one-dimensional Su–Schrieffer–Heeger (SSH) lattices. In this study, we investigate the relationship between the eigenvalue discreteness and the eigenstates behavior in 1D SSH lattices. The discreteness fraction ( D ) are introduced in combination with the inverse participation ratio to quantify this relationship. By employing the bulk-edge correspondence and perturbation theory, we derive an exact solution that accounts for both zero and non-zero modes. Our findings reveal a logarithmic relationship between the degree of eigenvalue discreteness and eigenstate localization in both the Hermitian and non-Hermitian conditions. This result provides a direct measure of edge-state localization strength in the topologically nontrivial phase.

Visible light absorbing manganese (Mn) -doping CDs were prepared by hydrothermal method, which exhibit orange–red emitting, and used as a photocatalyst for degrading acid fuchsin and malachite green. Through XPS analysis, Mn was successfully doped into the CDs. Under irradiation of the visible light, both of the degradation rates reached more than 95% in a short time. The used concentration of Mn-doping CDs is much lower than conventional ones, revealing the quite strong degradation ability. By comparing the optimal PL and UV–Vis absorption spectra of the CDs with and without Mn-doping, the effect of Mn-doping was revealed on the catalytic performance that Mn-doping altered the light-absorption position to the visible light region with a marked red-shift and the recombination rate of electron–hole pairs was reduced in the photo-chemical reaction process. Metal-doped CDs have not been used as photocatalysts, which have been achieved in this paper. Meanwhile, trap experiments were carried out to detect the reactive species related to the photo-degradation process of the two dyes, displaying that · O 2 − and OH · play the critical roles.

One-step pyrolysis method of N-doped carbon dots (CDs) with high conversion rate and high fluorescence quantum yield (QY) has been developed to manufacture CDs on a large scale for broad applications. The QY of the blue-emitting CDs is approximately 88%, while the conversion rate is higher than 80%. Unique to other studies, some of the challenges in the preparation of CDs were addressed through a systematic study, mainly focused on reduction in solvent usage, simplification of raw materials and removal of purification process. The synthesized CDs exhibit excellent optical properties and stabilities without additional purification. Then, to understand how highly luminescing the CDs are, the optical properties of the pyrolysis products were monitored over time, temperature and raw materials ratio. Furthermore, the morphology, surface structure, formation mechanism and photoluminescence of the synthesized CDs were also investigated by the different characterization techniques. Significantly, a single near-band edge transition mode is proposed for the excitation-independent emission behaviors of the as-prepared CDs.

We investigate the emergence of unconventional corner mode in a two-dimensional (2D) topolectrical circuits induced by asymmetric couplings. The non-Hermitian skin effect of two kinked one-dimensional (1D) lattices with multiple asymmetric couplings are explored. Then we extend to the 2D model, derive conditions for the non-Hermitian hybrid skin effect and show how the corner modes are formed by non-reciprocal pumping based on 1D topological modes. We provide explicit electrical circuit setups for realizing our observations via realistic LTspice simulation. Moreover, we show the time varying behaviors of voltage distributions to confirm our results. Our study may help to extend the knowledge on building the topological corner modes in the non-Hermitian presence.

Highlights The commonly used modification methods for separator of lithium batteries are summarized, which include surface coating, in situ modification and grafting modification. The adhesion of coating materials with the separators and wettability of the modified separators prepared from the three methods are compared. The challenges and future directions of separator modification are provided. The growing demands for energy storage systems, electric vehicles, and portable electronics have significantly pushed forward the need for safe and reliable lithium batteries. It is essential to design functional separators with improved mechanical and electrochemical characteristics. This review covers the improved mechanical and electrochemical performances as well as the advancements made in the design of separators utilizing a variety of techniques. In terms of electrolyte wettability and adhesion of the coating materials, we provide an overview of the current status of research on coated separators, in situ modified separators, and grafting modified separators, and elaborate additional performance parameters of interest. The characteristics of inorganics coated separators, organic framework coated separators and inorganic–organic coated separators from different fabrication methods are compared. Future directions regarding new modified materials, manufacturing process, quantitative analysis of adhesion and so on are proposed toward next-generation advanced lithium batteries. Graphical abstract

Highlights Solid polymer electrolytes formed in situ via covalent organic framework-induced ring-opening copolymerization. Solid polymer electrolytes with a high lithium-ion transference number and desirable interfacial compatibility. Li⁺ migration mechanisms investigated with density functional theory and molecular dynamics simulations. Solid polymer electrolytes (SPEs) have garnered considerable interest in the field of lithium metal batteries (LMBs) owing to their exceptional mechanical strength, excellent designability, and heightened safety characteristics. However, their inherently low ion transport efficiency poses a major challenge for their application in LMBs. To address this issue, covalent organic framework (COF) with their ordered ion transport channels, chemical stability, large specific surface area, and designable multifunctional sites has shown promising potential to enhance lithium-ion conduction. Here, we prepared an anionic COF, TpPa-COOLi, which can catalyze the ring-opening copolymerization of cyclic lactone monomers for the in situ fabrication of SPEs. The design leverages the high specific surface area of COF to facilitate the absorption of polymerization precursor and catalyze the polymerization within the pores, forming additional COF-polymer junctions that enhance ion transport pathways. The partial exfoliation of COF achieved through these junctions improved its dispersion within the polymer matrix, preserving ion transport channels and facilitating ion transport across COF grain boundaries. By controlling variables to alter the crystallinity of TpPa-COOLi and the presence of –COOLi substituents, TpPa-COOLi with partial long-range order and –COOLi substituents exhibited superior electrochemical performance. This research demonstrates the potential in constructing high-performance SPEs for LMBs.

Conventional preparation methods of carbon dots (CDs), generally causing low atom utilization and environmental unfriendliness due to the use of massive solvents, make it difficult for CDs to be synthesized on a large scale. In this work, a one-step solid-phase pyrolysis method was used to address the problems mentioned above. Selecting citric acid and natural biomass glycine as raw materials, through studying influences of the pyrolysis temperature, time, and raw material ratio on properties of the product, it is found that the ratio of citric acid to glycine plays a dominating role to luminescing color and fluorescence intensity of products. Eventually, the glycine-doped blue- and green-emitting fluorescent CDs (GCDs-b and GCDs-g) were prepared by the solid-phase pyrolysis, with high quantum yields of 84.0% and 63.0% and product yields of 71.5% and 64.5%, respectively. Moreover, the uniform and spherical GCDs-b and GCDs-g with average particle size of 4.1 nm and 3.5 nm, respectively, were well-dispersed in aqueous solution, exhibiting excellent and different optical properties, salt tolerance, pH, and light stabilities. Furthermore, in order to explore the influences of surface functional groups on luminescing color of the products, investigation was done on the surface chemical structure, composition, and the characteristics of optical spectra in the formation processes of GCDs-b and GCDs-g. It is rarely reported that the green light emission is related to carbon atom structure and amidation on surfaces of CDs. Additionally, the cellular viability assay of GCDs-b and GCDs-g was also conducted to verify its good biocompatibility, which guarantees these materials can be applied in cellular imaging.

Orthogonal integration of thermosensitive images is of vital significance for advanced anticounterfeiting, which however remains formidably challenging due to the trade‐off that facile thermoresponse needs easy molecular motion while robust imaging requires molecular restriction. Herein, a viable approach is demonstrated to tackle the challenge by in situ fixing a predesigned aggregation induced emission luminogen (AIEgen) at the polymer/liquid crystal (LC) interface via precisely controlled interfacial engineering, in which the AIEgen is enriched in LC phases during polymerization induced phase separation and subsequently driven to the interface by the interfacial thiol‐ene click reaction. Crosstalk‐free integration of holographic and fluorescent dual‐thermosensitive images with high sensitivity, high contrast ratio, and robust performance is successfully realized in a single unit, attributed to the simultaneously LC‐facilitated AIEgen molecular motion and polymer‐restricted AIEgen diffusion at the interface. The exciting characteristics of these orthogonally integrated dual images will enable them to prevent illegal replication and thus are expected to be promising for high‐security‐level anticounterfeiting applications. A novel type of advanced materials for security are deliberately designed with the AIEgen chemically fixed at the holographic polymer/liquid crystal interface, based on which the orthogonal integration of high contrast thermosensitive holographic and fluorescent dual images is demonstrated. There dual images show attractive thermoresponsivity and high robustness, promising for high‐security‐level anticounterfeiting applications.

Switchable catalysis promises exceptional efficiency in synthesizing polymers with ever-increasing structural complexity. However, current achievements in such attempts are limited to constructing linear block copolymers. Here we report a visible light regulated switchable catalytic system capable of synthesizing hyperbranched polymers in a one-pot/two-stage procedure with commercial glycidyl acrylate (GA) as a heterofunctional monomer. Using (salen)Co III Cl ( 1 ) as the catalyst, the ring-opening reaction under a carbon monoxide atmosphere occurs with high regioselectivity (>99% at the methylene position), providing an alkoxycarbonyl cobalt acrylate intermediate ( 2a ) during the first stage. Upon exposure to light, the reaction enters the second stage, wherein 2a serves as a polymerizable initiator for organometallic-mediated radical self-condensing vinyl polymerization (OMR-SCVP). Given the organocobalt chain-end functionality of the resulting hyperbranched poly(glycidyl acrylate) ( hb -PGA), a further chain extension process gives access to a core-shell copolymer with brush-on-hyperbranched arm architecture. Notably, the post-modification with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) affords a metal-free hb -PGA that simultaneously improves the toughness and glass transition temperature of epoxy thermosets, while maintaining their storage modulus. Switchable catalysis promises exceptional efficiency in synthesizing polymers with increasing structural complexity but current achievements in such attempts are limited to constructing linear block copolymers. Here the authors report a visible light regulated switchable catalytic system capable of synthesizing hyperbranched polymers in a one-pot/two-stage procedure with commercial glycidyl acrylate as a heterofunctional monomer.

The flower-like micro–nano-MoS 2 was synthesized with aging at 220 °C for 16 h by an oil–water interface method. By various characterizations, the results showed that the reaction temperature played a great role in the crystal formation of MoS 2 , while the reaction time affected the size of the particles. Additionally, it was found that by adding different types of surfactants, along with the altered hydrophobicity, the obtained MoS 2 micro–nanoparticles exhibited different morphologies, such as flower-like micro–nanospheres, flower-like micro–nanorods, micro–nanorods, and micro–nanosheets. Meantime, in a series of photodegradation experiments on rhodamine B (RhB) and methylene blue (MB) under a fluorescent light (36 W) in the presence of H 2 O 2 , the flower-like MoS 2 micro–nanospheres displayed better photocatalytic performance than the flower-like micro–nanorods and micro–nanorods with the same specific area. This is probably related to their own petal structure, preventing from coagulation and resulting in the more stable fixedness of dye molecules on the surfaces, in comparison to that of the micro–nanorods. These results are seldom reported and particularly of great significance in applications of micro- and nanoparticles with different shapes. Especially, the pH of environments greatly influenced on the photocatalytic reaction; the most effective photodegradation on RhB was at pH 6.0 while that for MB was at pH ≥ 9.0. It is mainly due to their different molecular structures and the difference in electric charge between the two dyes at different pH. Given its high efficiency for degrading RhB and MB dyes, the synthesized MoS 2 micro–nanoparticles revealed to be a promising photocatalyst to deal with contaminated water and some other relative fields.