Materials Chemistry Frontiers最新文献

Photothermal catalysis, as an emerging technology, has attracted much attention owing to its high efficiency and excellent sustainability. Current industrial processes integrating solar energy with fossil fuels for large-scale chemical production remain hindered by several challenges, including dynamic catalytic site restructuring that alters product selectivity and progressive catalyst deactivation that compromises economic viability. Therefore, a reasonable structural design could enormously enhance the mass and energy transfer during catalytic reactions. Considering the complexity of the reaction micro-environment, catalytic site reconstruction plays a crucial role in dynamic photothermal catalysis. Taking into account the spatial and temporal reaction processes, this review is focused on the latest progress of the catalytic sites confined to different three-dimensional (3D) structures. Initially, we provide an introduction to the mechanism of photothermal reaction on 3D structures, focusing on the mass and energy transferring pathways and the corresponding reactions. Subsequently, several typical distribution types of the catalytic sites are discussed, emphasizing that various 3D configurations modified with different types of catalytic sites would drive different reactions, including the biological enzyme site interaction process. We further elucidate the dynamic reconstruction of active sites under varying microenvironmental conditions, primarily induced by small-molecule adsorption and weak interfacial fields. Moreover, the applications of photothermal 3D materials are discussed under realistic reaction conditions, opening a new window for filling the gap between micro-structure and macro-process in catalysis. Finally, we briefly summarized the future challenges in solar-assisted catalytic engineering.

Preparing carbon dots with multicolor emissions and revealing their synthesis mechanisms have become a research focus. In this work, a confined synthesis method was introduced to synthesize blue, green, yellow and red carbon dots. It was observed that within the interlayer space of 2D layered double hydroxides, the emission wavelengths of the synthesized carbon dots were significantly regularly shifted. Experimental and theoretical analyses revealed that the confined microenvironment resulted in a 2D crystallized and reduced state structure. Moreover, the emission wavelength could be further exquisitely regulated by changing the microscopic arrangement of the reactants in a confined space. This study represents a significant advance in manipulating the nanostructures of carbon materials utilizing a confined environment.

Time variations in the photoluminescence (PL) properties of four types of imide compounds (ICs) with ether (OD-IC), thioether (SD-IC), dibenzofuran (BO-IC), and dibenzothiophene (BS-IC) cores dispersed in polymer films were investigated to elucidate the effects of the introduction of sulfur atoms and the structural rigidity of the ICs on their PL properties under continuous UV irradiation. These ICs exhibit photoactivated delayed phosphorescence (PH) from the excited triplet state (T₁), which is called prolonged irradiation-induced delayed luminescence (PIDL), after a few minutes of induction time, during which only fluorescence is observed. This result is because oxygen quenching efficiency gradually weakens as the ground-state oxygen decreases via energy transfer from the ICs in the T₁ state. As compared with the ICs containing ether linkages (OD-IC, BO-IC), the PHs of the ICs containing thioether linkages (SD-IC and BS-IC) were significantly enhanced by the heavy atom effect, and these showed bathochromic (red) shifts of the PL peaks owing to the extended π-conjugation. Furthermore, the ICs containing five-membered cores (BO-IC and BS-IC) demonstrated longer PIDL lifetimes and shorter induction times than those of the ICs containing flexible linkages (OD-IC and SD-IC), owing to their structural rigidity. In particular, BS-IC exhibited an excellent PIDL properties such as the largest intensity (I = 2480), a long lifetime (τ_PIDL = 410 ms), and a short induction time (t_ID = 1.55 min) owing to the rigid core containing a sulfur atom. Based on the results, this study provides a valuable strategy for developing novel PIDL materials.

The increasing prevalence of bone injuries and the current lack of effective repair solutions present a significant clinical challenge. Chitosan-based hydrogels have gained widespread use in bone regeneration and repair due to their favorable biocompatibility, biodegradability, and antimicrobial properties. Advances in preparation techniques have enabled the development of various tailored chitosan-based hydrogels, including nanogels, nanofibers, microspheres, and scaffolds, which are successfully applied in bone tissue regeneration. However, there is currently a lack of comprehensive reviews covering tailored chitosan hydrogels specifically for bone tissue repair. This paper addresses that gap by comprehensively summarizing the preparation processes of tailored chitosan-based hydrogels, along with their specific applications in bone regeneration. It aims to inspire innovative designs for improved chitosan-based hydrogels and foster expanded applications, ultimately leading to better therapeutic outcomes for patients with bone-related diseases.

Elemental two-dimensional (2D) materials, commonly referred to as Xenes, have attracted recent attention due to their many unique/remarkable chemical and physical properties. Xenes hold immense promise for multifarious applications across diverse domains, including optoelectronics, energy storage, energy conversion and biomedicine. Beyond graphene and phosphorene, a new cadre of Xenes has emerged, with particular attention directed toward antimonene, arsenene, tellurene and selenene. These nascent Xenes have garnered substantial interest due to their diverse allotropes, as well as their distinctive layer-dependent and modifiable properties, rendering them highly adaptable for engineering and catalytic applications. Herein, an overview is provided for the recent advancements in the structures, inherent properties and degradation behavior of Xenes, drawing upon both theoretical and experimental research. The synthesis methods of Xenes are summarized and primarily classified as bottom-up and top-down approaches. Furthermore, the catalytic potential of Xenes is elaborated, emphasizing both engineering strategies and theoretical understanding toward enhanced performance across a spectrum of catalytic reactions. Conclusively, a summary and perspectives on the future development of Xenes are given to boost their development.

Regulating molecular conformation changes is crucial yet challenging for manipulating multiple-responsive emissions in excited-state intramolecular proton transfer (ESIPT) materials. In this work, we explored the specific emission regulation of a dual-ESIPT-active molecule, BDIBD (2,5-bis(4,5-diphenyl-1H-imidazol-2-yl)benzene-1,4-diol), by subtly controlling the ground and excited states through different crystallization conformations. Notably, the crystals obtained in dimethylformamide (BDIBD–DMF) and methanol (BDIBD–MeOH) exhibited a single emission band, corresponding to the green and red emission from the keto^1st and keto^2nd excited states, respectively, while the crystals obtained in acetone (BDIBD–ACE) displayed dual emissions from both states, resulting in an overall yellow color. A comprehensive theoretical study verified that the modified intermolecular interactions, due to different crystallization conformations, regulated emissions by affecting the energy barrier of dual-ESIPT processes. The above results provide a concrete understanding of the regulation of excited-state emissions through ground-state conformational changes in ESIPT processes, as well as unique insights into the design and application of novel ESIPT emission materials.

To develop advanced materials based on calamitic nematic liquid crystals, it is essential to design functional optoelectronic mesogens that can form nematic phases at low temperatures. This study proposes a new molecular design strategy for low-temperature nematic liquid crystals using large π-conjugated mesogens with optical/electrical functions. Bridged biphenyls were synthesized by bridging the two phenyl rings with propylene. This bridging structure reduced the molecular planarity and prevented the molecules from aligning neatly in one direction, resulting in lowering the temperature range of the nematic phases. Terphenyl and phenyltolane derivatives exhibited supercooled nematic phases at room temperature, while quarterphenyl and bis(phenylethynyl)-biphenyl derivates exhibited nematic phases below 100 °C. The proposed design is more effective for rigid mesogens compared to conventional calamitic nematic liquid crystal design.

The efficacy of reactive oxygen species (ROS)-related skin tumor therapies is significantly restricted by intracellular overexpressed glutathione (GSH) which is a free radical scavenger. Herein, a GSH-depleting and high ROS production nanoreactor (MFO@MIL) is constructed by in situ loading manganese ferrite (MnFe₂O₄) onto an iron-based metal organic framework (MIL-101). The MFO@MIL is then incorporated into polycaprolactone (PCL) to prepare a porous skin scaffold, aiming to continuously release MFO@MIL and simultaneously regulate intracellular reducibility and ROS yield to enhance anti-tumor efficacy. Particularly, MnFe₂O₄ with GSH peroxidase-like activity can persistently deplete GSH to reduce its consumption of hydroxyl radicals (˙OH), which are produced by the Fenton reaction between MIL-101 and hydrogen peroxide (H₂O₂). Meanwhile, the depletion process of MnFe₂O₄ to GSH will produce Mn²⁺, which collaborates with MIL-101 to catalyze H₂O₂ to produce ˙OH, remarkably increasing ˙OH yield and enhancing anti-tumor efficacy. The results showed that the depletion rate of GSH using the scaffold reached 84.4% within 24 hours. The ˙OH yield of the scaffold was significantly higher than that of the scaffold loaded with MIL-101 alone. Systematic cell experiments demonstrated the powerful anti-tumor efficacy of the scaffold. This study proposes a feasible strategy to enhance ROS-based anti-tumor efficacy.

Natural enzymes inevitably suffer from inherent limitations, including low stability, high cost, sensitive catalytic activity toward environmental stimuli, and difficulties in recycling and reusing. To address these limitations, a number of enzyme mimics, particularly nanozymes, have been widely explored as superior candidates to mimic natural enzymes because of their low cost, high stability, flexibility and controllable catalytic activity. Because of their outstanding physicochemical properties, nanozymes demonstrate widespread applications in disease diagnosis and treatment, antibacterial agents, chemical sensing, and environmental pollutant monitoring and remediation. This review summarizes recent progress in the design and fabrication of nanozyme-based materials and their catalytic mechanisms and application in environmental pollutant detection and remediation. The present challenges and future perspectives are discussed for the development of multifunctional nanozyme material systems with high-efficiency, high-selectivity, and good stability. Further expansion of their real-world applicability in environmental fields would greatly inspire more novel research directions in this emerging area.

The quality of organic semiconductor films plays a crucial role in carrier transport and the overall performance of organic phototransistors (OPTs). Various approaches have been explored to enhance the morphology of organic films, and one effective method involves using crystalline templates with large domain sizes to promote the growth of the upper active films. However, strategies for obtaining continuous and uniform template layers over large areas are still in high demand. Herein, we employ a “solution epitaxy” method to fabricate a uniform C₃₂H₆₆ crystalline film as the template layer, facilitating the growth of the organic semiconductor 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) over a large area. Our results demonstrate that the morphology of the epitaxial films strongly depends on the morphology and thickness of the template layer. By optimizing the template layer, we successfully obtain terraced-like organic semiconductor films with excellent crystallinity with large domain sizes. These epitaxially grown films are then employed as carrier transport channels in OPTs, leading to the development of high-performance devices with a sensitivity of 3.74 × 10⁶ and a responsivity of 6.2 × 10³ A W⁻¹. Furthermore, the obtained phototransistors show promising potential for emulating synaptic behavior with their dependence on illumination power intensity and UV light addition time. This finding provides a feasible strategy for obtaining high-quality organic films with efficient charge transport and high photoresponse properties.