Materials Chemistry Frontiers最新文献

All-solid-state lithium batteries (ASSBs) with high energy density and intrinsic safety have received increasing attention, and their performance largely depends on cathode materials. Lithium-rich manganese-based materials (LRMs) have been regarded as the most promising cathode material for next-generation lithium-ion batteries owing to their high theoretical specific capacity (>250 mA h g⁻¹) and low cost. However, existing challenges, including irreversible oxygen release, poor electrochemical reaction kinetics and cycle stability, and voltage decay/hysteresis, have seriously impeded their further commercial application. Furthermore, the application of LRMs in solid-state batteries has rarely been reviewed. In this review, we first elucidate the crystal structure, the electrochemical reaction mechanism and the origin of the high capacity of LRMs. Secondly, we comprehensively summarize the development of LRMs in the systems of solid-state batteries in recent years, and the interfacial chemical/electrochemical stability between the cathode and solid electrolyte is highlighted, which is the main factor determining the performance of ASSBs. Finally, we discuss the challenges and prospects facing the development of high-performance solid-state batteries with LRMs cathodes. Particularly, we highlight the combination of LRMs with halide solid electrolytes processing high ionic conductivity as well lithium/silicon carbon anodes with high specific capacity to construct high-performance solid-state batteries in the future.

Designing noble metal-free electrocatalysts remains a challenge for the oxygen evolution reaction (OER) in alkaline solutions. In this study, we present a facile electrodeposition approach coupled with an in situ anodic oxidation method to synthesize NiOOH–MnS/NF on nickel foam (NF), successfully creating NiOOH–MnOOH/NF heterojunctions to boost OER performance under alkaline conditions. The heterojunction's synergistic effect significantly modulates the adsorption energy of the rate-determining step (RDS), thereby enhancing the intrinsic electrocatalytic activity of the NiOOH–MnOOH/NF electrocatalyst. Furthermore, the introduction of SO₄²⁻ leads to a variable degree of electron loss in both Mn and Ni, reducing adsorption strength of the OER intermediates and thus optimizing reaction kinetics. The as-prepared NiOOH–MnOOH/NF electrocatalyst demonstrates exceptional OER performance in 1.0 M KOH, achieving a current density of 100 mA cm⁻² with a Tafel slope of 52.3 mV dec⁻¹ and a minimal overpotential of 391 mV. Utilizing NiOOH–MnOOH/NF as a bifunctional electrode for overall water splitting (OWS), the system operates at a low potential of 1.66 V at 10 mA cm⁻², showcasing its excellent durability. This work offers novel insights and promising prospects for the advancement and practical application of non-precious metal electrocatalysts in the field of electrocatalytic water splitting.

The micro/nano-structural design of 2D interlayers greatly enhances the electrochemical energy and kinetics of the supercapacitor electrode. Herein, a hetero-Co₉S₈ QD-doped 2D CoNi-LDH with the proper content was constructed through diverse sulfurization time, showing a 3D flower-like microsphere. The highly dispersed active QDs on 2D layers promoted both rapid ion/electron transfer kinetics and electrochemical storage capacity, which were evidenced by experiments and density functional theory calculations. As a result, the assembled hybrid supercapacitor QDs-Co₉S₈/CoNi-LDH//activated carbon displays a maximum energy density of 33.3 Wh kg⁻¹ at a power density of 820.0 W kg⁻¹. Furthermore, the in-depth analysis of interlayer ion diffusion and formation of quantum dots in heterostructure provides a good way for synthesizing high-performance electrode materials with adjustable size and composition.

Diabetic wounds are one of the most serious complications of diabetes mellitus caused by neurovascular injury and microenvironmental disorders, including hyperinflammation, hypoxia, and persistent infection, requiring multiple interventions at different stages. However, the traditional treatment only targets the wound and ignores the intrinsic pathogenesis, resulting in a limited therapeutic effect. One promising option is hydrogels, which have good biocompatibility, adhesion, and plasticity. Incorporating conductive materials into hydrogels further enhances their therapeutic effects by accelerating hemostasis, promoting nerve and vascular regeneration, and enhancing the anti-inflammatory, antioxidant, and antibacterial effects, which is the future development direction for treating diabetic wounds. This review systematically analyzes the role of electricity in treating diabetic wounds and discusses the material selection and methods for the functional realization of conductive hydrogels. Furthermore, the main challenges and future perspectives in this field are discussed and prospected, aiming to fuel and foster the development of conductive hydrogels in diabetic wound therapy.

Near-infrared (NIR) photosensitizers have immense potential for in vivo phototherapy due to minimal scattering of NIR light in biological tissues. Among various types of photosensitizers, BODIPY dyes are potential candidates for phototherapy owing to their high molar extinction coefficient and tunable photophysical properties. However, most NIR BODIPY photosensitizers have relatively complicated structures and lengthy synthesis approaches, restricting their practical application. In this work, a simple strategy of chalcogen modification was applied to tune the photophysical properties of iodinated BODIPY for enhanced NIR phototherapy. As the atomic radius of chalcogen atoms increases, the BODIPY-X (X = O, S, Se, and Te) dyes exhibit a red-shifted absorption from 558 nm, 610 nm, and 618 nm to 660 nm, a faster singlet oxygen generation rate, and higher photothermal conversion efficiency due to the heavy atom effect. This modification facilitates intramolecular charge transfer (ICT) and enhances intersystem crossing (ISC), critical for effective PDT and PTT. To improve hydrophilicity and delivery efficiency, we encapsulated BODIPY-X using the amphiphilic copolymer Pluronic F127, creating F127/BODIPY-X nanoparticles (NPs). These NPs exhibited enhanced solubility and bioavailability, crucial for therapeutic efficacy. Moreover, the F127-encapsulated BODIPY-Te nanoparticles exhibit the best anti-tumor efficiency on U87-bearing mice, which is consistent with their outstanding photothermal conversion and photodynamic performance. Hence, a chalcogen modification strategy with a simple synthesis approach paves a new way for tuning the photophysical properties of NIR photosensitizers and could stimulate the rapid development of NIR phototheranostic agents.

The daunting challenge in exploring biochar-based adsorbents to realize both fast adsorption kinetics and high capacity calls for the development of effective approaches for biochar functionalization and activation. Hereby, we present a two-step sequential melamine functionalization and KOH etching of biochar derived from dead-leaf waste biomass. When appropriate melamine functionalization is implemented, violent gas evolution occurs in the 2nd-step KOH activation via etching the C–OH and CO to yield C–O–C sites while chemically reducing −NO_x to other N configurations. The 1st-step melamine functionalization plays a critical role in deepening the KOH-based activation, bringing more N/O-containing groups, enhancing porosity, and boosting the adsorption kinetics and capacity for tetracycline (TC) removal. The optimal sample exhibits a specific surface area (SSA) and pore volume of 1995.03 m² g⁻¹ and 1.190 cm³ g⁻¹, respectively, much superior to the counterpart with only one-step KOH activation (1275.34 m² g⁻¹ and 0.621 cm³ g⁻¹). Occurring over a homogeneous, melamine/KOH-coactivated biochar surface, the adsorption process is found to be driven by both physisorption and chemosorption in a monolayer manner. The prominent SSA and enriched N/O imparted via the double chemical activation render the adsorption kinetics rather fast, with only 30 min required to reach equilibrium. Meanwhile, a superior maximum monolayer adsorption capacity of 433.74 mg g⁻¹ is realized. The adsorbent is also demonstrated to be recyclable and reusable through five cycles of repeated usage. The adsorption process is disclosed to be spontaneous in nature, while TC concentration dictates whether the adsorption is exothermic/entropy-reducing or endothermic/entropy-gaining, with lower TC concentrations leading to the former. Furthermore, we find that hydrogen bonding interactions are the critical driving force for the uptake of TC over the biochar prepared by the double chemical activation. This work sheds light on the exploration of double chemical activation to engineer the architecture and surface functionalities of biochar materials simultaneously for environmental remediation and beyond.

Multivariate metal–organic frameworks (MTV-MOFs) demonstrate strong potential as self-calibrating fluorescent sensors with desirable features of high stability and reliability due to the incorporation of multiple emissive centers and diverse functionality into a single material. In this work, a ligand substitutional metal–organic matrix HIAM-3001-PNT-25% with a ratiometric dual-emissive fluorescence response toward ammonia and aliphatic amines is designed and constructed. HIAM-3001-PNT-25% exhibits a sensitive fluorescence response toward ammonia and aliphatic amines in aqueous solutions, with a detection limit towards ammonia of 0.299 ppm. Furthermore, the influence from the pore-coordination sphere induced by hydrogen bonding interaction is analyzed systematically through fluorescence titration measurements, DFT calculations and an independent gradient model based on Hirshfeld partition analysis, which has offered helpful interpretation to the observed sensing behavior. The doping system demonstrates heightened sensitivity to cadaverine and can be fabricated into pliable films, which can be utilized as an indicator of meat freshness. This work reveals the crucial roles of the electron acceptor moiety on pore-coordination interaction and brings prospects for the development of efficient amine monitoring systems.

Perovskite quantum dots (QDs), with outstanding properties, including tunable emissions, high color purity, and low cost solution processability, have become promising candidates in light-emitting applications. However, the inherent instability issue strongly restricts further development and commercialization of light-emitting devices based on perovskite QDs. As well investigated in conventional QDs, the construction of QDs with core–shell structure is recognized as an effective way to improve the stability and optimize luminescent properties at the same time. Inspired by the unique structure diversity of perovskite materials, 2D/3D FAPbBr₃@GA₂PbBr₄ QDs are proposed and fabricated through a one-step phase transfer enhanced emulsion synthesis. By systematically tuning the ratio between GABr and FABr as well as a combined analysis with X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, absorption and photoluminescence spectrum characterizations, a well-defined core–shell structure is demonstrated for FAPbBr₃@GA₂PbBr₄ QDs under an appropriate ratio of GABr/FABr. Compared to the original QDs, the as fabricated core–shell QDs exhibit an enhanced exciton binding energy and improved stability under heat, light, and moisture exposure. Moreover, phosphor converted light-emitting diodes based on the core–shell QDs are also fabricated with a much improved device performance than that of QDs without a core–shell structure, proving the superiority of FAPbBr₃@GA₂PbBr₄ QDs in light-emitting applications.

Early diagnosis and treatment of liver fibrosis can effectively prevent chronic liver disease from developing into hepatocellular carcinoma (HCC). Conventional techniques to detect liver fibrosis are complex and expensive. The development of non-invasive and sensitive surface-enhanced Raman scattering (SERS) can significantly reduce the time and cost, which is important for improving the efficiency of diagnosis and detection of liver disease. In this study, we developed a cubic core–shell Cu₂O@Ag SERS bioprobe for label-free identification of HCC and hepatic fibrosis. The constructed composite substrate has shown impressive SERS sensitivity and good stability. Trace molecules (alizarin red and rhodamine 6G) with concentrations as low as 10⁻¹⁰ mol L⁻¹ could be detected. Cubic Cu₂O@Ag also exhibited good SERS stability, since the smallest relative standard deviation (RSD) of Cu₂O@Ag-MB (methylene blue) was only 8.80%. Then, the spectral analysis of these three molecules (AR, MB, and R6G) was carried out by applying a machine learning-assisted LDA model, and the classification accuracy reached 100%. Subsequently, four different types of hepatocytes were identified and classified by using the established model and label-free SERS detection with a desirable accuracy of 91.38%. This innovative technology will further facilitate the early diagnosis of HCC and liver disease and assist in the rationalization of clinical treatment.

Inspired by the structural similarity between dog turbinates and pine tree (PT), PT was successfully carbonized into carbon materials with a similar structure to that of dog turbinates at different temperatures. We used PT-derived carbon materials for gas sensor research and carbonized PT by the pyrolytic carbonization method. The materials were characterized using SEM, TEM, X-ray, XRD, FT-IR, UV-vis, XPS, and EDS. It was found that carbonized pine tree (PTC) samples developed orderly porous structures with large specific surface areas. At room temperature, the response to 500 ppm ethylene glycol (C₂H₆O₂) was 9.3 k%, theoretical detection limit was 0.1064 ppm, response time was 3.522 s, recovery time was 3.997 s, and common interference gases such as ammonia, ethanol, acetone have good immunity, compared with the fresh sensor; after 45 days, the sensor's response to C₂H₆O₂ fluctuated less than 2.1%, and it still had good recovery in 10 consecutive response recovery cycles, realizing high sensitivity, stability and selective detection of C₂H₆O₂ and providing a reference value for the research and development of low-cost, high performance and good stability gas sensors and effective utilization of the biomass waste.