Materials Chemistry Frontiers最新文献

In the pursuit of channel materials for high-performance n-type organic electrochemical transistors (OECTs), several challenges have been encountered, including difficulties in the modification of the material structure, relatively low performance, and poor stability. To address these issues, designing innovative electron-deficient building blocks is critical for constructing novel donor–acceptor organic semiconductors with low LUMO levels to achieve high-performing n-type OECTs. In this study, we have designed and synthesized a novel glycolated quinone-based electron-deficient building block derived from azaisoindigo (AQM2I), featuring a cross-conjugated planar backbone and low LUMO levels, attributed to enhanced O–H interactions and strong electron-withdrawing amide groups. By combining AQM2I with alternating electron-rich building blocks (T, TT, 2T and 2FT), a series of novel n-type polymers that possessed mixed ionic–electronic conductivity were prepared. The incorporation of various electron-rich building blocks effectively modulates the backbone structure, molecular energy levels and sodium doping capability of the polymers. Moreover, a mixed conducting property with a maximum μC* figure-of-merit value of 0.53 F V⁻¹ cm⁻¹ s⁻¹ for accumulation-mode n-type OECT was achieved, attributed to the high electron mobility induced by the enhanced lamellar stacking, smooth and dense film morphology. The design strategy for novel electron-deficient building blocks presented in this work provides insights for the development of high-performance materials for n-type OECTs.

Pure organic long-persistence luminescence has recently garnered significant attention due to its diverse potential applications. Nonetheless, the attainment of pure organic dual-mode long-persistence afterglow with high efficiency remains a significant challenge. Herein, we report the successful realization of high-efficiency, color-tunable dual-mode room-temperature phosphorescence (RTP) along with thermally activated delayed fluorescence (TADF) of approximately 50 ms, utilizing an aromatic furan organic host–guest system. Our investigation into this system reveals two key findings: (1) the heavy-atom effect of the host and guest molecules plays distinct roles in modulating the efficiency of the intersystem crossing (ISC) and reverse intersystem crossing (RISC) processes; and (2) the dual-mode long-persistence luminescence can be effectively adjusted by manipulating the energy gap between the excited triplet states of host and guest molecules. Additionally, we demonstrated the capability for color display utilizing this host–guest system through inkjet printing.

Metastable-phase materials possess unique structures, high Gibbs free energy, abundant active sites, and adjustable physicochemical properties, making them ideal candidates for optimizing electrocatalysis. As metal oxides are stable under harsh reaction conditions, by controlling the morphology, defects and phase structure of the material, the surface electronic structure of metal oxides can be adjusted to a great extent, and their catalytic performance can be optimized. As a novel addition to the 2D material family, metastable-phase noble metal oxides exhibit significant promise for catalytic reactions. Here, the latest research progress and advantages of 2D metastable-phase noble metal oxides are reviewed, and their application in acidic electrocatalytic water splitting is presented. Finally, the challenges associated with 2D metastable-phase noble metal oxides and future perspectives are discussed.

Luminescent solar concentrators (LSCs) have garnered considerable attention for their potential to enhance solar energy harvesting in photovoltaic (PV) systems. However, self-absorption often hinders their efficiency, caused by the overlap between the absorption and emission spectra. Herein, we design, synthesize, and study a series of novel excited-state intramolecular proton transfer (ESIPT) dyes as a new class of self-absorption-free luminophores for efficient transparent LSC-PV devices. HBTM, HBTPM, and HBTBP dyes comprise 2-(benzo[d]thiazol-2-yl)phenol as an electron-donating ESIPT unit functionalized with different π–acceptor moieties of ((3-hexylthiophen-2-yl)methylene)malononitrile, (4-(3-hexylthiophen-2-yl)benzylidene)malononitrile, and (4-(3-hexylthiophen-2-yl)phenyl)(phenyl)methanone, respectively. Theoretical and photophysical analyses confirm the ESIPT nature of these dyes. They show absorption in the UV-blue region and orange-red emissions with large Stokes shifts (4388–10269 cm⁻¹) and decent fluorescence quantum yields (28–47%). Their LSC samples are well prepared by dispersion in a transparent polymethyl methacrylate (PMMA) matrix. The LSC slabs possess good photophysical properties of the dyes with minimal overlap integrals (OI*) of 0.28–1.56% and edge emission efficiencies (η_edge) of 47–57%. Photovoltaic performance assessments reveal power conversion efficiencies (PCE) of 0.46% to 0.68% with external photon efficiencies (η_ext) of 7.69% for HBTM, 6.91% for HBTPM, and 2.98% for HBTBP. Particularly, HBTBP-based LSC exhibits excellent transparency (AVT = 93%; CRI = 97) suitable for window applications. This work represents a significant step toward reducing self-absorption in LSCs while improving photovoltaic performance, paving the way for scalable solar concentrator technologies based on organic materials.

Although poly[bis(4-phenyl) (2,4,6-trimethylphenyl)amine] (PTAA) has been extensively investigated as a hole transport material, its performance regarding stability and efficiency still encounters challenges. In this study, through the introduction of a novel guest molecule BQ-BO, the energy level configuration, hole transport, and interface passivation of PTAA have been significantly enhanced. The large conjugated electron-deficient core and methoxy-substituted triphenylamine arm structure of BQ-BO not only optimize the HOMO energy level but also enhance the hole mobility and conductivity, attaining a photoelectric conversion efficiency of 21.81%. It also exhibited outstanding thermal stability, maintaining an initial efficiency of 90% after 1000 hours of continuous heating at 85 °C, in contrast to a pure PTAA-based device whose efficiency dropped to 70% after 400 hours.

Radioactive strontium-90 (⁹⁰Sr²⁺) in wastewater poses a significant threat to both the environment and living organisms. Conventional treatment strategies, such as ion-exchange resins followed by cement solidification, can still carry the risk of leakage under certain conditions. Low-silica zeolites have demonstrated strong cation sorption capabilities, with CHA zeolites showing particular promise for nuclear wastewater treatment. However, synthesizing low-silica CHA zeolites with Si/Al ratios around 2 typically requires fluorides or complex crystallization processes. In this study, we present a one-step, fluoride-free synthesis method for low-silica CHA zeolites using the silicoaluminophosphate (SAPO) zeolite SAPO-35 as the seed. The SAPO-seeded synthesis method enhances the formation of Al-pairs within the CHA framework by releasing partially connected Si and Al species from the SAPO seed. This significantly improves the zeolite's capability to capture the divalent Sr²⁺. The resulting zeolite exhibits a 10% higher Sr²⁺ sorption capacity per ion-exchange site compared to CHA zeolites synthesized without the SAPO seed. The synthesized zeolite exhibits exceptional Sr²⁺ removal efficiency across dosages of 1/50–1/500 g mL⁻¹ and the pH range of 3–12. At temperatures of 25 °C, 60 °C, and 80 °C, the sorption capacities reach 112 mg g⁻¹, 144 mg g⁻¹, and 186 mg g⁻¹, respectively. This work highlights the potential of SAPO-seeded synthesis as a practical and scalable approach for producing Al-pair-enriched, low-silica CHA zeolites, indicating the high effectiveness for removing ⁹⁰Sr²⁺ from nuclear wastewater and offering a promising solution for radioactive wastewater management.

In recent years, the issue of increasing electromagnetic pollution has posed significant challenges for researchers in the field of electromagnetic dissipation, highlighting the urgent need for effective solutions. Metal–organic frameworks (MOFs) have garnered considerable attention due to their compositional designability, large specific surface area, and tunable chemical structure, making them highly desirable precursors for electromagnetic wave absorption materials (EMWAMs). MOF-based EMWAMs exhibit remarkable performance advantages, such as lightweight properties, high loss capability, and a wide effective absorption bandwidth. These advantages are primarily attributed to their excellent impedance matching and multiple attenuation mechanisms. This paper provides a concise discussion on the relationship between the mechanisms and microstructure of EMWAMs. The research progress of MOF-based EMWAMs in recent years is reviewed, including the classification of MOF and MOF composite precursors, design principles and preparation methods. Finally, the problems, challenges and future opportunities of MOF-based EMWAMs are presented. We aim for this review to offer new insights into the design and fabrication of MOF-based EMWAMs, thereby enhancing both the fundamental understanding and practical application of these materials.

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.

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.