Materials Chemistry Frontiers最新文献

The development of intelligent polymer materials with high phosphorescence quantum yields (Φ_phos.) and ultralong phosphorescence lifetimes (τ_phos.) simultaneously under ambient conditions is significant but very challenging. In this work, two new organic luminogens, namely BCzS and BCzSF, were synthesized by attaching dibenzothiophene and diphenyl sulfone to the nitrogen atom of 9H-dibenzo[a,c]carbazole via a palladium-catalyzed carbon-nitrogen coupling reaction, respectively. Subsequently, they were employed as guest compounds and doped into the mixtures of bisphenol A diglycidyl ether and 1, 3-propylenediamine, respectively, followed by an in situ polymerization to produce doped epoxy polymer (EP) films BCzS-EP and BCzSF-EP. It was found that the resulting polymer films showed high Φ_phos. and τ_phos. values of up to 13.5% and 3.01 s, respectively, and could produce conspicuous green organic afterglow with a duration time of over 20 s under ambient conditions. Moreover, the BCzS-EP and BCzSF-EP films exhibited controllable and reversible photoactivated UOP properties, in which their organic afterglow could be facilely turned on and off by the stimuli of light and heat. Given the unique photophysical properties and excellent flexibility and transparency, the BCzSF-EP film was successfully used for erasable light printing. This work provides a new direction for developing intelligent and flexible polymer materials simultaneously with high Φ_phos. and τ_phos. values.

The development of inexpensive and efficient oxygen evolution reaction (OER) catalysts is crucial for the large-scale application of water splitting to produce green hydrogen. Different from traditional preparation methods, in this study, the electronic structure of ternary NCM (LiNi_0.94Co_0.05Mn_0.01O₂) was directly reconstructed from the cathode of spent lithium-ion batteries through electrochemical de-lithiation technology to obtain efficient OER catalysts. The optimized NCM94-1V-90 min exhibits a low overpotential of 270 mV at 10 mA cm⁻² along with excellent stability for a 300 h durability test. The high OER performance is attributed to the electronic structure reconstruction and microstructure transformation during electrochemical de-lithiation, which generates a large number of high-valence Ni³⁺ and O vacancies as well as structural fragmentation, respectively, supplying more active sites and enhancing electronic conductivity, also confirmed by the density functional theory (DFT) theoretical calculation. The strategy of electrochemical de-lithiation technology to improve the OER electrocatalytic performance not only can recycle the cathode materials of lithium-ion batteries, but can also be extended to other electrode materials of spent batteries.

Copper-based SSZ-13 (Cu-SSZ-13, CHA topology) zeolite catalysts have been commercialized towards the selective catalytic reduction of NO_x with NH₃ (NH₃-SCR), but the applications of Cu-SSZ-13 catalysts are still limited by the great challenge of high-cost organic templates. To this end, zeolite catalysts with other topologies have been attempted to substitute SSZ-13 to achieve the target of low cost and high performance. Herein, a series of SUZ-4 zeolites (SZR topology), structurally related to the FER topology, are successfully synthesized by using tetraethylammonium hydroxide (TEAOH) as the organic template. Compared to SSZ-13 zeolites synthesized by the addition of N,N,N-trimethyl-1-adamantylammonium hydroxide (TMAdaOH), the obtained SUZ-4 zeolites show higher economic benefits. Moreover, copper-exchanged SUZ-4 (Cu-SUZ-4) zeolites exhibit comparable NH₃-SCR performance to commercial Cu-SSZ-13. Particularly, the NO conversion of the Cu-SUZ-4-2 zeolite with optimal Cu loading is above 90% in the temperature range of 250–550 °C at high gaseous hourly space velocity (200 000 h⁻¹). After hydrothermal ageing (HTA), the NO conversion of Cu-SUZ-4-2-HTA is close to 90% in the temperature range of 300–550 °C, indicating its high hydrothermal stability. The present work provides an alternative catalyst that can potentially substitute SSZ-13 with high NH₃-SCR catalytic properties and low cost.

Three fused-ring electron acceptors, MC8-4H, MC8-4F and MC8-4Cl, featuring a new type of macrocyclic side chain were synthesized and applied in organic solar cells. The chemical structure of MC8-4H was unambiguously determined using single crystal X-ray diffraction analysis. The single crystal structure of MC8-4H indicates that the compact macrocyclic alkyl chain stretches over the central fused-ring core unit and causes a slight bending of the backbone. Among these three acceptors, MC8-4F shows the highest electron mobility of 6.64 × 10⁻⁴ cm² V⁻¹ s⁻¹ and the best performance in solar cells. Cells based on MC8-4F and the donor L4 exhibited power conversion efficiencies up to 14.68%.

The rapidly increasing concentration of atmospheric carbon dioxide (CO₂) is a growing threat to human society. Selective capture of CO₂ remains challenging but of global importance. Recent work on porous materials demonstrated their potential and effectiveness in ameliorating the CO₂ problem. This review will summarize the progress in advanced porous materials, such as zeolites, metal–organic frameworks and porous organic polymers, with a tailored pore microenvironment and functionality for the selective capture of CO₂ over the past decade. The applications of porous adsorbents for CO₂ capture in important scenarios, such as flue streams, biogas and direct air capture, are presented. We discuss the design strategies for the custom-made structure and functionality of porous materials that have led to high-performance CO₂ capture with separation efficiency (e.g., high capacity, selectivity, molecular sieving, and moisture resistance) as well as efficient regeneration performance. In addition, this review also concludes with current existing challenges combined with potential directions for the future development of porous materials towards industrial CO₂ capture.

High-entropy catalysts (HECs) have been increasingly used in various applications in recent years. Owing to their multi-element composition and high-entropy mixing structure, HECs exhibit excellent catalytic performance in thermocatalysis, electrocatalysis, and photocatalysis. This comprehensive review focuses on the synthesis and catalytic applications of high-entropy alloys (HEAs), high-entropy oxides (HEOs), high-entropy sulfides (HESs), and other high-entropy catalytic systems. In this review, we point out several issues that require further exploration, including the controllable synthesis of HECs, identification of active centers, and regulation of elemental composition and structure of HECs. We hope that this review can help to further advance the development of HECs, in terms of optimizing the catalytic activities of HECs. Moreover, the “high-entropy” design concept behind these materials may also provide insights and solutions for addressing the challenges encountered in traditional simple systems.

We provide a comprehensive overview of the recent developments in the field of two-dimensional (2D) materials for energy conversion and storage applications. The focus of this review is the electronic structure tuning of 2D materials such as carbon/graphene, metal dichalcogenides, metal oxides/hydroxides, and MXenes for the hydrogen evolution reaction. This review begins with presenting a systematic classification, controllable synthesis, and formation mechanism of 2D nanomaterials. It then discusses the strategies for tuning the electronic structure of 2D nanomaterials and their impact on electro-/photo-catalytic properties, particularly through composite and heterostructure formation (0D/2D, 1D/2D, and 2D/2D). The latest advances in the development of electro-/photo-catalysts with novel nanosheet structures and compositions are discussed in detail. The correlation between the electronic nature; activity; and the shape, size, composition and synthesis methods of these materials is summarized. Finally, this review concludes with perspectives on future challenges and directions for research in this field.

Drug carriers have gained significant attention in recent years because of their ability to enhance the bioavailability of drugs and minimize adverse effects. However, some carriers prepared from inorganic or organic materials may cause secondary damage to healthy organs due to their toxicity. Therefore, it is imperative to develop efficient drug carriers that are made of biocompatible materials. DNA, as a biological endogenous substance, has enormous potential for efficient drug delivery due to its excellent biocompatibility, versatility in interacting with drugs, ease of functionalization, and ability to target desired sites specifically. With the advancement of DNA nanotechnology, DNA-based nanomaterials with sophisticated nanostructures have been developed, further expanding the applications of DNA for drug delivery. In this review, we provide an overview of recent advances in DNA-based drug carriers, focusing on the targeted accumulation mechanisms and loading, delivery, and targeted release of different drugs, including small molecule, nucleic acid, peptide, protein-based drugs, and others. In addition, we highlight some of the current challenges and prospects in this field.

Deep-red (DR)/near-infrared (NIR) emitters have extensive applications in bioimaging and flexible optoelectronics. However, it is challenging to design efficient DR/NIR emitters with high photoluminescence quantum yields (PLQYs), especially in the solid state, due to the energy gap law. A common strategy to develop new acceptors is to construct donor–acceptor luminogens with fine-tuned molecular structures. Nevertheless, new acceptors that are suitable for constructing highly efficient DR/NIR emitters are still rare. Herein, by utilizing cyano-substituted dithiafulvalene fused benzothiadiazole (BSMCN) as the acceptor and triphenylamine derivatives as donors, three BSMCN-based molecules, respectively, named 2TB, 2MTB, and 2MOTB, are rationally designed and efficiently synthesized. All three compounds exhibit aggregation-induced emission properties with their emission wavelengths extending from the DR to NIR region. Moreover, when applied in solution-processed non-doped devices, 2TB exhibits a high external quantum efficiency of 4.9% at a wavelength of 664 nm, demonstrating the great potential of BSMCN-based DR/NIR AIEgens in developing non-doped OLEDs.

The design of metal cluster-based materials exhibiting exceptional circular dichroism (CD) and circularly polarized luminescence (CPL) performance has garnered significant attention due to their promising applications in 3D displays, photoelectric devices, and encrypted information storage. With the rapid advancement of metal cluster chemistry and characterization techniques, numerous atomically precise metal clusters and nanoclusters have emerged over the past two decades, providing an ideal platform for systematic investigation into the correlation between the optical properties of chiral metal clusters and their structures. The present review aims to elucidate how the regulation of chiral metal cluster structures affects their CD or CPL signals, with the ultimate objective of providing a reference for the rational design of CPL materials in the future. Specifically, the correlation of typical chiral metal clusters and their corresponding CD signals is first discussed. Subsequently, we summarize recent progress in CPL-active metal clusters and analyse their luminescence nature. Finally, we provide a summary of our findings and present the challenges and prospects in this field.