Materials Chemistry Frontiers最新文献

One of the most widely used artificial non-nutritive sweeteners in food is sucralose (SC), which provides sweetness with few or no calories. For monitoring its concentration in foodstuffs, a novel selective and sensitive electrochemical sensor was developed using carbon dots (CDs) and synthetic molecularly imprinted polymers (MIPs) on the surface of a glassy carbon electrode (GCE). Density functional theory (DFT) was used not only to screen potential monomers for polymerization but also to investigate the interactions of the SC molecules with the proposed monomers. The outstanding selectivity of the sensor stems from the synthesized imprinted polymers. The 3D cavities in the polymer surface originated from the physical interaction between SC and methyl methacrylate and acrylamide monomers. The synthesized imprinted polymers were thoroughly examined using EDX spectroscopy, AFM, FTIR spectroscopy, SEM, TEM, BET analysis, and elemental mapping analysis. In addition, the electrochemical behavior of the synthesized sensors was then described by means of electrochemical impedance spectroscopy and cyclic voltammetry. The innovative platform exhibited good selection for SC molecules in the presence of other coexisting species, cost-effectiveness, and ease of use. In addition, it showed good sensitivity (2.04 × 10⁻¹⁰ mol L⁻¹) with a wide linear range (6.2 × 10⁻¹⁰–7.1 × 10⁻³ mol L⁻¹), superior constancy (7 weeks), and high precision (RSD = 3.4%). As a result, the proposed imprinted sensor was effectively utilized to detect SC, using differential pulse voltammetry, in food and beverage samples with outstanding recoveries (98.8–100.0%).

Patchy micelles derived from diblock copolymers serve as versatile building blocks for colloidal assemblies due to their ability to mediate directional interactions via discrete surface patches. Here, we demonstrate a strategy for tuning the morphology of diblock copolymer micelles and their assemblies by controlling the degree of core cross-linking. By varying the amount of cross-linker, single-, two-, and three-patch micelles were formed, which subsequently guided the assembly into dimers, linear chains, and branched structures, respectively. A low degree of cross-linking led to significant core swelling, resulting in elongated cores and the formation of additional patches. Reducing the molecular weight of the copolymer also enabled morphological tuning at a smaller length scale. Furthermore, varying the degree of cross-linking in spherical micelles with long coronas led to the formation of structurally diverse dimers and chains, which were effectively used as templates to organize Au nanoparticles into spatially distinct paired and linear arrays.

The development of high-performance and long-lasting rechargeable zinc–air batteries (ZABs) requires efficient and durable bifunctional oxygen electrocatalysts that can facilitate both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). This advancement is crucial for enhancing the overall performance and longevity of rechargeable ZABs. However, it remains highly challenging to integrate independent ORR and OER active sites into a catalyst with high bifunctional activity. Herein, we report a simple approach to design a nonprecious metal catalyst by immobilizing iron phthalocyanine (FePc) onto Ni nanoparticle-loaded porous graphene-based heterostructures (PGHS) via π–π interactions. Owing to these interactions the resultant FePc@Ni-PGHS catalyst synergistically facilitate the ORR and OER bifunctional electrocatalytic performance. Consequently, as an air electrode in ZAB, it achieves a peak power density of 152 mW cm⁻², a large specific capacity of 862 mAh g⁻¹, and stable cycling performance for 124 h. These findings emphasize its potential as a low-cost alternative to precious metal-based electrocatalysts, offering a pathway to more sustainable and efficient electrochemical energy conversion and storage technologies.

Bacterial infections caused by drug-resistant bacteria have become a significant health challenge in the 21st century. Photodynamic therapy (PDT), a novel approach for treating drug-resistant bacterial infections, has attracted considerable attention due to its broad-spectrum antimicrobial activity, non-invasive, and highly selective advantages. However, the “always on” nature of conventional PDT often leads to unintended damage to surrounding healthy tissues. To address this issue, stimuli-responsive photodynamic therapeutic (SRPT) platforms with adjustable antibacterial activity have been developed. These SRPT platforms remain inactive in normal tissues and are only triggered to exhibit antimicrobial activity under specific stimuli at the targeted site. This review comprehensively summarizes the contributions of SRPT platforms to the treatment of bacterial infections over the past few years and offers insights into their future development. Specifically, this review delves into the design mechanisms and the latest advancements of SRPT platforms in combating bacterial infections. Particular emphasis is placed on key factors such as pH, redox status, enzymes, and dual-stimulation as the primary design directions for activation strategies.

Perovskite solar cells (PSCs) have garnered significant attention owing to their solution fabrication, cost-effectiveness, and high power conversion efficiency, yet their practical application has been hindered by instability issues. Under operational conditions, redox reactions have been found to be prevalent in perovskite devices, but the underlying mechanism remains very unclear. Here, we systematically investigated the impact of light irradiation, atmosphere and interfacial structures on the redox kinetics in PSCs. Our results show that oxygen acts as a predominant factor driving device degradation, other than the transport layer or spectral components. Spectroscopic results reveal that the formation of iodine-related defects, e.g., triiodide ion (I₃⁻) and iodine (I₂), are dramatically boosted under oxygen-rich conditions, and can be further accelerated by light exposure. These findings provide critical insights into the redox reaction mechanism of perovskite-based materials, and offer a potential direction for enhancing the long-term stability of PSCs.

We present the synthesis and comprehensive characterization of a new class of hybrid inorganic–organic materials: polyhedral oligomeric silsesquioxane (POSS) cages functionalized with 1-haloacetylene groups (Cl, Br, I). These building blocks undergo a unique, catalyst-free, solid-state thermal polymerization. This process results in highly cross-linked poly(1-haloacetylene) networks. The resulting polymers—polyPOSS-C₂Cl, polyPOSS-C₂Br, and polyPOSS-C₂I—exhibit direct optical band gaps of 2.79, 2.74, and 2.38 eV, respectively, and maintain the structural integrity of the POSS core, as confirmed by solid-state NMR (¹³C, ¹⁵N, and ²⁹Si), DRIFT, Raman, and PXRD analyses. Kinetic studies indicate pseudo-second-order polymerization with activation energies between 179 and 217 kJ mol⁻¹. These materials are completely insoluble in common solvents and thermally stable up to 309 °C. Their robust structure, high thermal resistance, and semiconducting properties highlight their potential for advanced optoelectronic applications.

Mn⁴⁺-activated phosphors are widely used in plant lighting due to their efficient far-red emission (600–760 nm). However, their narrow emission bandwidth limits their applications. To address this, we co-doped Fe³⁺ with a broadband far-red/near-infrared (NIR) emission (650–900 nm) with Mn⁴⁺ in a spinel-structured MgAl₂O₄ host. This strategy synergistically combines the luminescence characteristics of both ions to achieve a broadened spectral output. Upon 285 nm ultraviolet excitation, the Fe³⁺/Mn⁴⁺ co-doped MgAl₂O₄ system exhibits a dual-peak broadband emission spanning 600–900 nm, with emission maxima at 655 and 722 nm. Notably, the full width at half maximum (FWHM) reaches 132 nm, representing a 109% increase relative to the Mn⁴⁺ singly doped sample (FWHM = 63 nm). The dual-peak broadband emission is highly consistent with the absorption bands of the two types of phytochrome (Pr and Pfr). This spectral matching enables bidirectional control of the phytochrome photoconversion cycle. This work establishes an innovative strategy for developing broadband far-red phosphors that dynamically regulate phytochrome activity to advance precision plant lighting.

Paper—an essential carrier for information dissemination and the inheritance of civilization—holds significant importance in both daily life and specific applications. Nevertheless, the acidification of paper reduces its mechanical strength, restricts its functionality, and considerably shortens its service life. In this research, a handmade acid-free paper (HMAP) with an initial pH of 7–8 was prepared by incorporating ultrathin magnesium–aluminum layered double hydroxide (LDH) nanosheets as a filler in the paper preparation process. The Mg–Al LDH nanosheets, with an average layer thickness of about 8 nm, were synthesized via a one-step surfactant-assisted hydrothermal method. Simultaneously, the HMAP exhibits the advantages of long service life and acid resistance after a prolonged accelerated aging experiment (two months), maintaining a pH above 6. Additionally, the HMAP also possesses potential application value in some domains such as flame retardancy and adsorption. This work substantiates the feasibility of ultrathin LDH as a paper filler and broadens its prospects in the preparation of acid-free long-life paper.

The efficiency of perovskite solar cells is constrained by surface and bulk recombination, along with poor band alignment at the interfaces of the transport layers. In our study, we demonstrate that modifying the surface and grain boundary (GB) of perovskite using tetraphenylethylene-enamine (TPE-en) enhances band alignment at the perovskite-hole transport layer interface and mitigates recombination within the perovskite material. By leveraging the solubility of small organic molecules in orthogonal solvents, we introduce TPE-en onto the perovskite surface akin to anti-solvent methods. Our investigation reveals a significant enhancement in the short circuit current density, fill factor, and open circuit voltage of the surface-modified (SM) perovskite. Specifically, we achieve a total power conversion efficiency of 18.73% (MA_0.9AA_0.1PbI₃). Comparative analyses show TPE-en outperforms other reported TPE derivatives in device performance. Through systematic interface analysis, we observe that TPE-en effectively reduces surface and GB defects by elevating the HOMO levels of the perovskite, introducing an interface dipole at the perovskite-spiro-OMeTAD interface. Optical measurements such as time-resolved photoluminescence, Ultraviolet photoelectron spectroscopy, and X-ray photoelectron spectroscopy were used to investigate the cause of this improvement. A 0.28 eV surface dipole formed provided effective band alignment, resulting in enhanced hole extraction and photovoltaic performance.

Afterglow carbon dots have attracted a lot of attention due to their unique advantageous properties, such as high sensitivity and resistance to interference from background light. However, achieving dual-mode afterglow emission from the single-mode afterglow of carbon dots remains a challenge. Here, we achieved the induction of a carbon dot afterglow emission mode through solvent effects. In this method, boric acid is used to construct a rigid plane to suppress the non-radiative transition of triplet excitons, and the afterglow of carbon dots can be changed from dual-mode emission, to single-mode emission to no afterglow emission under H₂O, DMF and MeOH environments during the synthesis. Notably, the solvent contains different hybrid forms of the nitrogen element, which have different effects on the delayed fluorescence: sp² hybrid nitrogen causes the delayed fluorescence to disappear and sp hybrid nitrogen induces a slight increase in delayed fluorescence. Meanwhile, doping with N effectively improves the quantum yield of CDs@BA. Finally, carbon dots with different afterglow properties were obtained in different solvent environments and applied in temperature sensing and anti-counterfeiting. This work provides a design idea and a feasible strategy to construct carbon dots with different afterglow properties.