Materials Chemistry Frontiers最新文献

Electrocatalysts that exhibit bifunctional activity for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are essential for advancing the sustainability of clean energy. Using density functional theory (DFT) computations, we systematically investigated the catalytic performance of 17 transition metal single atoms embedded in two-dimensional ZnO for the ORR and OER. Our results indicate that these single atoms strongly interact with ZnO, forming stable single-atom catalysts (SACs). Among them, Ni–ZnO is identified as a promising bifunctional ORR/OER catalyst due to its low overpotentials (η^ORR = 0.42 V, η^OER = 0.54 V). Furthermore, employing the constant potential method, the η^ORR (0.32 V) and η^OER (0.31 V) values can be further reduced under acidic conditions. Machine learning (ML) analysis revealed that the number of outermost electron (N_e) and first ionization energy (E_i) are the two primary descriptors governing OER activity, while ORR activity is mainly influenced by E_i and the atomic radius (R_TM). This study provides theoretical guidance for designing low-cost, efficient bifunctional ORR/OER electrocatalysts and demonstrates the potential of ML in elucidating the relationship between intrinsic catalyst properties and their catalytic activity.

Photochromic molecules are light-responsive compounds that undergo reversible structural changes when exposed to light, producing isomers with different absorption spectra. Their ability to switch between molecular states with different optical properties makes them valuable for use in smart materials, anti-counterfeiting systems, optical data storage and optoelectronic devices. Diphenyl-naphthopyrans are a type of photochromic system that has attracted particular interest due to their tunable absorption spectra, fast response times and good fatigue resistance. However, their relatively narrow and selective absorption in the visible spectrum limits their use in applications requiring neutral colouration, such as smart windows and ophthalmic lenses. To address this limitation, we investigated which structural modifications could be employed to adjust the key optical and photochromic properties, such as the absorption range, colouring ability, and isomerisation kinetics. In this study, we present a strategy for obtaining novel push–pull photochromic dyes with wide, panchromatic absorption. Our approach involves replacing a phenyl unit with a ferrocene unit within the diphenyl-naphthopyran framework, while also adding an anchoring acceptor group to create a push–pull structure. We present the synthesis of five new dyes, detailing their optical and electrochemical properties. We investigated their photochromic behaviour in both solution and the solid state by grafting them onto metal oxide surfaces or dispersing them in a polymer matrix. Our results demonstrate that these dyes can be used to effectively produce panchromatic photochromic coatings. Furthermore, we show that some of these compounds act as efficient photosensitisers in dye-sensitised solar cells (DSSCs).

The advancement of wearable electronics requires flexible power sources with durable electrodes to withstand dynamic operational conditions. Among diverse materials for electrodes, carbon nanotubes (CNTs) emerge as an ideal material due to their unique structure, high aspect ratio, and tunable surface chemistry, enabling versatile architectures from fibers to films and sponges. This review systematically examines CNT-based flexible electrodes for zinc-ion batteries (ZIBs), highlighting recent breakthroughs in multifunctional wearable applications achieved through optimized CNT architectures. Key strategies in component engineering and structural design are discussed to enhance mechanical–electrochemical performance. Furthermore, critical correlations between material properties, electrode design, and practical applications are established. By providing methodological insights and technological roadmaps, this comprehensive analysis advances the development of CNT-based flexible electrodes for next-generation electrochemical energy storage systems.

Solid-state stimuli-responsive circularly polarized luminescent (CPL) materials hold significant potential for applications in 3D displays, multi-level encryption, and chiroptical devices. However, research on CPL switching in solid-state carbon dots (CDs) remains unexplored. Herein, we construct photo-switchable solid-state CD based CPL-active assemblies by simultaneously encapsulating both CDs and spiropyran (SP) into chiral metal–organic frameworks (CMOFs) as the host. It is found that the SP units in the CMOF@CD/SP assemblies exhibit a colorless closed-ring state and a blue open-ring state under alternating ultraviolet (UV) and visible light irradiation, which regulates the inactivation and activation of the photochromic fluorescence resonance energy transfer (FRET) process, respectively, between the CDs and the SP units, thereby enabling reversible photoswitching of both photoluminescence (PL) and CPL properties. Leveraging these reversible CPL switching properties, the assemblies are successfully applied to high-security 3D barcodes, chiral logic gates, and 3D printing for the first time, providing innovative solutions for information security and logic computing.

Stabilizing reactive radical ions for practical use under harsh conditions remains challenging. Here, we effectively screen electroactive perylene-conjugated dyads (Peri–DPA(R))^0/˙+/˙−, where R represents substituent groups (CN, F, Me, and OMe), for their distinctive visible-region absorption, high stability without spectral degradation, and reversible redox behavior with electrochromism. Notably, radical cations (Peri–DPA(R)˙⁺) demonstrate superior stability and redox reversibility by combining D–A architecture, spin delocalization, and enhanced aromaticity, with performance improving as the electron-donating ability of the substituents increases. Theoretical calculations further reveal that redox-induced structural changes increase electron density toward the perylene π-system, facilitating favorable delocalization of the unpaired electron in the radical cations.

Straightforward strategies for preparing nanozymes with multi-enzyme mimetic activities are highly desirable for various significant fields including biosensing, environmental monitoring, tumor therapy and biocatalysis. While till now, very few of these nanozymes have been designed, particularly for establishing multimode point-of-care testing (POCT) platforms to realize accurate in situ detection without expensive, bulky instruments. Herein, an innovative 3D hierarchical hollow flower-like cobalt–copper coordination polymer decorated with Cu_XO and CuCo₂O₄ nanoparticles (CuCoCPNFs@Cu_XO/CuCo₂O₄) was fabricated via a convenient one-pot approach in the absence of any surfactants and templates. Intriguingly, the resulting CuCoCPNFs@Cu_XO/CuCo₂O₄ shows exceptional ability to mimic the activities of a variety of bioenzymes, such as peroxidase (POD), oxidase (OXD), catalase (CAT), superoxide dismutase (SOD), laccase (LAC), and ascorbic acid oxidase (AAO). On account of the inhibitory effect of epinephrine (EP) on the POD-like activity of CuCoCPNFs@Cu_XO/CuCo₂O₄, a straightforward and label-free triple-mode POCT platform was established for EP determination. This platform provides output signals in the form of color, temperature, and RGB values, which can be monitored using UV-vis absorption spectroscopy, a thermometer, and a smartphone, respectively. The practicability and performance of the proposed EP sensing strategy were further certified in real serum samples. Therefore, the established sensing platform, which integrates multi-enzyme simulated active nanomaterials with a multi-mode POCT approach, provides new inspiration for in situ real-time detection with high sensitivity, selectivity, and accuracy.

The advancement of organic light-emitting diodes technology has increased the demand for luminescent materials with high solid-state luminescence efficiency and stable amorphous properties, particularly for ultraviolet (UV)-emitting materials, where doping strategies are ineffective. This study focuses on improving the amorphous stability of UV-emissive 2′,5′-dioxy-p-terphenyls by incorporating triorganosilyl groups at the 3 and 3′′-positions, enhancing their glass transition temperature and preventing crystallization. Density functional theory calculations confirm that silyl group incorporation has minimal impact on the electronic structure, maintaining UV emission. The silicon-decorated terphenyls that are readily synthezied exhibit higher thermal stability and improved amorphous properties compared to their parent counterparts. Differential scanning calorimetry analysis reveals that terphenyls modified with triphenylsilyl groups show the highest glass transition temperature and amorphous stability. Photophysical analysis demonstrates that these materials exhibit amorphization-induced enhanced emission, an rare phenomenon where fluorescence efficiency in the amorphous state is higher than that in the crystalline state. These findings highlight the effectiveness of silicon-based molecular modifications in stabilizing amorphous nature of UV-emitting materials. The approach preserves the UV-emissive properties of the parent chromophores while improving their thermal and morphological stability and luminescence efficiency in the amorphous state.

In this study, we explored the use of two 3D printing techniques, direct ink writing (DIW) and digital light processing (DLP), as novel and flexible strategies to control the 3D geometry and morphology of functional materials. To demonstrate their potential, different types of carbon nitride (C₃N₄) were combined and successfully printed with various polymers, such as methylcellulose (MC) and polysulfone (PSF). C₃N₄ is a metal-free photoactive material, which has recently gained significant interest due to its attractive optoelectronic properties. The 3D printed C₃N₄-based composites were tested in typical potential applications for their photo-, piezo- and electrocatalytic activity. Tailored formulations and design strategies were devised for pollutant photo- and piezoelectric degradation as well as electrochemical sensing, showing the effect of the formulation on the performance of the 3D printed C₃N₄ polymer composites. The performance evaluations revealed promising results, complemented by the stability of the 3D printed geometries in organic solvents commonly used in chemical syntheses. Specifically, the DIW g-C₃N₄/PSF formulation showed the highest overall pollutant removal (71%), followed by the DLP g-C₃N₄-based formulations which showed high removal efficiencies (up to 63%) with a high level of piezoelectric degradation (up to 41%). In addition, Piezoresponse Force Microscopy (PFM) analysis of both the starting bulk g-C₃N₄ powder and DIW 3D printed bulk g-C₃N₄/MC composite revealed significant piezoelectric properties, broadening their potential applications.

Rational design and structural modulation of MOF materials are crucial to developing high-performance supercapacitor electrodes. In this research study, high-performance bimetallic MOF supercapacitor electrode materials have been successfully fabricated via a cerium-induced strategy. The addition of cerium not only adjusts the morphology of the Co-MOF but also enhances the oxygen vacancy defects. Notably, the Co₄Ce₁-MOF material possesses a unique nanorod-like morphology, which greatly increases the specific surface area, shortens the ion transport routes and exposes more active sites. Meanwhile, the higher oxygen vacancy concentration in the Co₄Ce₁-MOF suggests its more pronounced oxygen vacancy defects compared to the Co-MOF. These findings provide an innovative strategy for the fabrication of MOF-based high-performance electrode materials for supercapacitor applications.

Circularly polarized room-temperature phosphorescence (CPRTP) materials integrating room-temperature phosphorescence (RTP) and circularly polarized luminescence (CPL) show great promise for frontier applications like optoelectronics. Herein, we report a chiral luminophore Ben-2Chol, which can self-assemble into micrometer-scale sheets in the aggregated state of solution and spin-coated films and achieve circularly polarized fluorescence (CPF) through aggregation-induced chirality transfer, with the maximum g_lum reaching −1.1 × 10⁻³. Notably, its liquid-phase-diffused fibrous microcrystals exhibit CPRTP with inverted polarization relative to the sheets, featuring g_lum values of +6.0 × 10⁻³ (blue) and +1.0 × 10⁻³ (yellow-green) with a 41.7 ms of luminescence lifetime. Mechanical grinding eliminates RTP/CPL, confirming crystallization-induced properties. This study provides a simple strategy for constructing CPRTP materials through aggregation-induced chirality transfer in microcrystals, offering new insights for the design of chiral luminescent materials with dual functionalities.