Materials Chemistry Frontiers最新文献

The crystal structure, phonon dispersion curves, electronic transport parameters, and thermoelectric (TE) properties of the Zintl phase BaCaPb compound are investigated by first-principles calculations in combination with a two-channel model. The regular residuals analysis demonstrates the crucial role of four-phonon scattering behavior in evaluating the thermal transport properties of the BaCaPb compound on account of the noticeable optical–optical gap. The origin of the rattling vibration behaviour is investigated by the quantitative analysis of chemical bond. The diffusion-like phonons are predominantly influenced by the rattling vibration of the Ba atom in the BaCaPb compound. Moreover, the dual role of the lone electrons in Pb and the rattling vibration of the Ba atom contributes to the ultralow lattice thermal conductivity (1.46 W m⁻¹ K⁻¹@ 300 K) in the BaCaPb compound. In addition, the TE properties of the BaCaPb compound are evaluated in consideration of multiple carrier scatterings, and optimal figures of merit (ZTs) of 1.7 and 1.0 are achieved for the n-type and p-type BaCaPb compounds at 600 K. The present work not only reveals the excellent TE properties of the Zintl phase BaCaPb compound through an in-depth study of their thermal and electronic transport properties, but also adopts a two-channel model for the theoretical design of high-efficiency TE materials.

Electrochemical synthesis of ammonia (NH₃) through cathodic nitrate reduction presents an effective alternative to the Haber–Bosch process, enabling efficient ammonia production without significant environmental pollution. The electrocatalytic degradation strategy is an efficient and environmentally friendly tool for the treatment of oily wastewater containing partially hydrolized polyacrylamide (HPAM). Thus, coupling cathodic nitrate reduction with anodic HPAM oxidation can further enhance ammonia synthesis efficiency and HPAM degradation efficiency. Here, we reported an N-doped carbon nanotube loaded with CuNi-x (x = 0.5, 1, 2) as an electrocatalyst for cathodic nitrate reduction coupled with anodic HPAM oxidative degradation. Notably, the CuNi-1 variant achieved the highest ammonia yield of 4962.76 ± 40.22 μg h⁻¹ mg_cat⁻¹ and a faradaic efficiency of 85.91 ± 0.42%. Furthermore, the oxidative degradation rate of HPAM reached a maximum of 81.91 ± 0.36% within 2 h. Anodic HPAM oxidation not only promotes cathodic nitrate reduction but also enables the acquisition of valuable anodic products. Using in situ ATR-SEIRAS, in situ DEMS, and DFT calculations, we thoroughly analyzed reaction intermediates and the critical role of the CuNi bimetallic system in electrocatalytic nitrate reduction. The coupled reaction system was established to achieve both efficient ammonia synthesis and HPAM degradation.

Efficient solubilisation of fullerenes in aqueous media is crucial for their photodynamic therapy (PDT) applications. We demonstrated the efficacy of guanidinium-appended γ-cyclodextrin (CD^Gu) as a novel solubiliser for C₆₀ and C₇₀ fullerenes, achieving exceptionally high aqueous concentrations of 3.1 mM and 0.37 mM, respectively, through simple mechanical mixing in the presence of Na⁺ ions. The resulting complexes, CD^Gu⊃C₆₀ and CD^Gu⊃C₇₀, enabled efficient fullerene transfer to cell membranes, a critical factor for PDT efficacy. Notably, CD^Gu⊃C₇₀ exhibited excellent singlet oxygen (¹0₂) generation (quantum yield Φ_Δ = 0.77 at 630 nm) and induced >90% cell death with only 5 min of white light exposure in vitro. This research highlights the importance of molecular dispersion in enhancing fullerenes’ photosensitising activity and membrane transfer, potentially advancing fullerene-based PDT approaches.

Type-I photosensitizers (PSs) have attracted great attention in recent years as they minimally rely on the tissue oxygen (³O₂) to generate highly cytotoxic reactive oxygen species (ROS) in the scope of photodynamic therapy (PDT). Thus, they hold great promise for effective treatment of hypoxic cancer cells, which is a challenging task for type-II PSs. However, compared to conventional type-II PSs, the number of cancer cell selective type-I PSs is quite low. Thus, there is still a need for type-I PSs that can induce photocytotoxicity only in cancer cells without causing damage to normal tissues even under light irradiation. Additionally, targeting PSs to specific organelles has lately appeared to be a promising approach to improve the therapeutic outcome of PDT. Although a few examples of organelle-targeted type-I PS cores have emerged recently, activity-based and organelle-targeted type-I PSs have remained scarce. In this study, we report two organelle-targeted and hydrogen sulfide (H₂S) responsive type-I PSs (HEHM and HEH) based on a highly modular and easily accessible heavy atom decorated hemicyanine core. HEHM localizes to mitochondria due to its cationic structure, whereas HEH targets endoplasmic reticulum (ER) as it bears an ER-targeting sulfonamide moiety, and it marks the first example of an activity-based and ER-targeted type-I PS based on a hemicyanine core. Both PSs can be selectively activated in neuroblastoma cells (SH-SY5Y) upon reacting with high levels of endogenous H₂S and induce similar photocytotoxicity through a type-I PDT mechanism under both normoxic (20% O₂) and hypoxic (1% O₂) conditions. HEHM is shown to cause PDT-induced mitochondria stress, while HEH triggers ER stress upon LED irradiation (640 nm, 66.7 mW cm⁻²). Additionally, HEH is shown to induce immunogenic cell death (ICD) followed by PDT action. In contrast, negligible ROS generation and cell death are observed in normal cells, which is a critical and challenging task for any type of therapeutic modality. They also allow fluorescence imaging of cancer cells due to their emissive nature, suggesting that they function as phototheranostic agents. This study introduces a rational approach to develop new generation activity-based and organelle-targeted type-I PDT agents towards effective and selective treatment of hypoxic tumors.

The preparation of anisotropic conducting hydrogels with high anisotropic conductivity using simple methods is a major challenge. Herein we present a new strategy for significantly enhancing the degree of anisotropic conductivity of hydrogel materials. Highly oriented Janus nanobelts are used as the building block to avoid undesirable interactions between conducting and insulating materials, resulting in highly conductive hydrogel materials. As a case study, in this paper, anisotropic conductive-luminescent bifunctional Janus nanobelt hydrogel array films (denoted as JAHFs) are prepared by parallel electrospinning and gelation, utilizing highly oriented Janus nanobelts, i.e. [Eu(TTA)₃(TPPO)₂/gelatin (GE)]//[carbon black (CB)/GE] Janus nanobelts, as building blocks. The high degree of integration between the highly oriented array film and the anisotropic conductive-luminescent materials endows the hydrogel material with high anisotropic conductivity and multifunctionality. The anisotropic conductivity of JAHFs is as high as 1.52 × 10⁵ when the mass ratio of CB/GE is 7%, which achieves a significant increase in anisotropic conductivity through a simple preparation method. JAHFs have a distinct red luminescence at 616 nm. The tunability of luminescence and conductive anisotropy is demonstrated by adjusting the contents of Eu(TTA)₃(TPPO)₂ and CB. The tensile strength and the elongation at break of JAHFs along the parallel direction of Janus nanobelts are 0.61 MPa and 80.75%. The good mechanical properties of JAHFs provide a guarantee for the assembly of strain sensors. JAHFs exhibited rapid responses under various tensile strains and temperatures, and the assembled strain sensors are utilized to detect human joint motion with good stability and sensitivity. This method is also applicable to the preparation of other multifunctional anisotropic conducting hydrogel materials. This study contributes new approaches and technical support for enhancing the anisotropic conductivity of hydrogel materials and sets the groundwork for developing other multifunctional conductive hydrogel materials.

Liquid metals (LMs) have attracted significant attention in the preparation of two-dimensional (2D) materials due to their unique self-limiting oxidation reactions. However, a single LM element needs to be heated and melted before being used to prepare 2D materials, whereas the addition of other elements for alloying can significantly reduce the melting point of the LMs, as sonicated LM techniques enable the high-yield production of 2D materials. Enlightened by this, 2D Bi-doped In(OH)₃ with an average thickness of 2.95 nm was successfully prepared for the first time from an eutectic bismuth–indium alloy LM using a one-step ultrasonic process, which enabled two-dimensionalization and doping of the material simultaneously. Such prepared 2D Bi-doped In(OH)₃ based humidity sensors exhibited a high sensitivity (98.94% towards 90% RH) and a low hysteresis (1.21% at 44% RH) over a wide relative humidity (RH) range of 9–90% RH, realizing the rare application of metal hydroxides in the field of humidity sensing. The enhanced humidity sensing performance can be attributed to the 2D Bi–In(OH)₃ structure, which offers an abundance of –OH groups and a high specific surface area. These characteristics synergistically promote the adsorption of water molecules, thereby improving the overall sensitivity of the humidity sensor. This study provides a novel approach for synthesizing 2D metal hydroxides, with the ability to extend to other low-melting metals and alloys, thereby broadening the application range of LM-based nano-functional materials.

Recent advancements in the application of non-conjugated polymers as emitters, host materials, or hole-transport materials have significantly impacted the development of thermally activated delayed fluorescent (TADF) organic light-emitting diodes (OLEDs). Non-conjugated linkers between donors and acceptors (D–σ–A) demonstrate significant importance in OLEDs because they can hinder direct conjugation between the donor and the acceptor, which is advantageous for realizing blue emitters and high-triplet-energy (both hosts and hole-transport) materials. Moreover, TADF small molecules polymerized via a non-conjugated backbone have been proven to be potential polymers for thermally activated delayed fluorescence applications. Non-conjugated polymers used as hosts and hole-transport materials have also been developed, considerably enhancing the device performance of TADF-OLEDs. These polymers represent a highly attractive class of luminescent materials for TADF-OLEDs, offering numerous advantages, such as environmental sustainability, over their conjugated counterparts. In addition to their role in improving device performance, non-conjugated polymers offer tunable energy levels and molecular flexibility, enabling better control over charge transport and exciton dynamics. The versatile structural designs of these polymers make them ideal candidates for multi-functional components in OLEDs, including hybrid materials that combine TADF and other photophysical properties. Consequently, a comprehensive review describing the detailed design strategies along with synthetic routes for these polymers, applied as emitters, hosts, and hole-transport materials in TADF-OLEDs, is essential. Herein, the design tactics, along with the optoelectronic and electroluminescence properties of non-conjugated polymers reported to date, are comprehensively explained. The review concludes by emphasizing the transformative potential of these polymers in the TADF-OLED field and highlights the importance of continued research and development in realizing their full potential. By providing a systematic overview of the current state of research of non-conjugated polymers and identifying key areas for future investigation, this review serves as a valuable resource for researchers and industry professionals working in the organic electronics field.

Low-cost and mass-produced anthracite is used herein as a carbon precursor to prepare a carbon anode for sodium-ion batteries (SIBs) through NaOH activation and a one-step carbonization process. To enhance the reaction kinetics and boost the sodium storage capability of anthracite-derived carbon (AC), boron quantum dots (BQDs) were fabricated and incorporated into the AC framework through simple freeze-drying of the mixtures with BQDs and AC and an annealing process. The electron-deficient properties of quantum-sized boron endow the AC framework with outstanding electrochemical performance. The ordered and disordered mixed structure of the AC framework provides more active sites for ion insertion and extraction, thus increasing capacity and improving the diffusion and transfer of both ions and charges. The boron solid-solution phases, such as BC₃, BC₂O and BCO₂, formed within the AC framework make it easier to store and release sodium ions, thereby achieving efficient sodium-ion adsorption and desorption during the charge–discharge process. Thus, the as-prepared BQDs/AC-1300 anode exhibits a high initial discharge capacity of 568.2 mA h g⁻¹ at 25 mA g⁻¹, a large reversible capacity of 287.5 mA h g⁻¹ at 50 mA g⁻¹, and superior long-term cycling stability of 89.8 mA h g⁻¹ at 1000 mA g⁻¹ over 1000 cycles. Galvanostatic intermittent titration analysis indicates that boron electron deficiencies create more ion adsorption sites and boost the pseudocapacitive charge storage capability, exhibiting remarkable charge transfer kinetics between sodium and active materials. The protocol for powering an anthracite-based anode by embedding BQDs should inspire far-ranging investigations into boron-based advanced battery systems.

Modern lifestyle changes, including irregular diets and late-night activities, have contributed to a significant rise in cancer rates, particularly among younger demographics, highlighting the pressing need for early detection and treatment. Fluorescence imaging techniques play a crucial role in tumor diagnosis, yet traditional organic fluorescent materials suffer from limitations such as poor photostability and fluorescence quenching in aggregates. This paper introduces the design and synthesis of four aggregation-induced emission (AIE) molecules with near-infrared I emission, which are aimed at overcoming fluorescence quenching in the molecular aggregation state. The photophysical properties of these molecules (BTA-TT, BTA-TTM, BTA-FT, and BTA-FTM) were investigated and they exhibited TICT and AIE behaviors in varying water fractions, along with notably large Stokes shifts. In vitro imaging of the four molecules successfully imaged lysosomes within 4T1 cells and they displayed minimal dark toxicity. Moreover, these AIEgens exhibited excellent anti-photobleaching properties, which were superior to those of commercial dyes. In addition, BTA-FTM nanoparticles coated with PEG-2000 showed biosafety and enabled tumor imaging in mice for 59 hours, revealing the tumor metastases in the heart and lungs of mice. This research contributes to the development of novel near-infrared molecules for advanced diagnostic applications.

Antibiotics are vital for treating microbial infections, but their overuse has led to antibiotic resistance, necessitating new antimicrobial strategies. Nanomaterials with antimicrobial properties were an alternative, like our designed nano-platform CPHG, which consists of PEI-modified graphene oxide and hyaluronic acid-coated copper ion chelated polydopamine. It could affect microbial metabolic activities through mild photothermal stimulation. Additionally, using the sharp, flake-like structure of graphene oxide, this structure could physically disrupt the microbial cell membrane, and change the membrane's permeability, which in turn further enhanced the permeability of the microbial membrane. Membrane damage caused by dual pathways could increase the permeability of the microbial membrane, promoting its absorption of copper ions. The efficiency of photothermal conversion was increased by incorporating copper ions. It also depleted the GSH within microbes, causing lipid peroxidation. Additionally, it induced a toxic stress response in proteins, leading to cuproptosis-like cell death. The CPHG effectively accomplished swift wound recovery in a Staphylococcus aureus-infected murine wound model. Furthermore, the application of this strategy to Escherichia coli and Candida albicans has also demonstrated excellent antibacterial effects. Hence, CPHG demonstrated promising capabilities in exhibiting wide-range antibacterial efficacy and provided a new approach to addressing the issue of antibiotic resistance. Its unique antimicrobial mechanism reduced the risk of microorganisms developing resistance, offering a new direction for future antimicrobial treatments.