Journal of Materials Chemistry C最新文献

Herein, we prepare a framework consisting of a Cu-MOF anchored on a graphitic carbon nitride (Cu-MOF/C₃N₅) nanomaterial for antioxidant sensing. The photocatalytic efficiency of the Cu-MOF was statistically increased by doping with g-C₃N₅. Cu-MOF/C₃N₅ has been shown to possess prominent laccase-like and catalase (CAT)-like activities, and can catalyze the oxidation of the antioxidants butylated hydroxyanisole (BHA) and tert-butylhydroquinone (TBHQ) to generate a color change in the presence of 4-aminoantipyrine (4-AP). Furthermore, the catalytic efficiency of the Cu-MOF/C₃N₅ nanozyme under near infrared (NIR) stimulation is 4 times higher than that obtained without NIR stimulation. On the one hand, the Cu-MOF/C₃N₅ with the CAT-like plasmonic nanozyme generated an abundance of high-energy hot carriers under NIR stimulation to promote the decomposition of H₂O₂ to generate abundant oxygen (O₂); on the other hand, the photothermal effect induced by the localized surface plasmon resonance (LSPR) on Cu-MOF/C₃N₅ significantly improved the reaction kinetics and thus resulted in an obviously enhanced laccase-like activity. There are linear relationships between the absorbance and BHA and TBHQ concentrations in the ranges of 0.033–2.67 mM and 0.033–2.67 mM with limits of detection of 0.0113 mM and 0.027 mM. Finally, Cu-MOF/C₃N₅ is successfully employed for colorimetric detection of BHA and TBHQ in electronic cigarettes.

In the present work, a one arrow two hawk approach was implemented to enable fluorometric trace level detection as well as photocatalytic remediation of antibiotic drugs tetracycline (TET) and doxycycline (DOX) using an M-CD and encapsulated bacterial cellulose (M-CDs@BC) luminescent hydrogel composite synthesized via a single-step one-pot hydrothermal method. The M-CDs showed a wide linear range, and good sensitivity with lower limits of detection (LOD) of 133 nM and 138 nM for TET and DOX, respectively. Encouraged by the remarkable fluorescence (FL) characteristics of M-CD@BC, the solid phase hydrogel platform was utilized to detect the concentration of TET and DOX in a sequential manner for the first time. The M-CDs@BC composite showed excellent sensing ability and selectivity towards TET and DOX, among other available antibiotics. Moreover, the photocatalytic activity of the M-CDs is found to be preserved in M-CDs@BC as well and played an effective role in the photodegradation of both TET and DOX (70.3% and 64.0%, respectively). Furthermore, the present M-CDs@BC hydrogels display high cycling performance for recurrent usage. Overall, the present work paves the way for the generation of unique CD composites for environmental remediation.

Dielectric ceramic capacitors have garnered extensive attention due to their fast charge–discharge speed, high power density, and thermal stability. This paper investigates Nd₂Ti₂O₇ ceramics, which are characterized by a monoclinic layered perovskite structure exhibiting a relatively uniform charge distribution. This structure can have a quick response to external electric fields. It can lead to an intrinsic energy storage efficiency of 85.6%. Furthermore, the uniform and compact microstructure of the ceramics minimizes internal defects, thereby preventing heat buildup during charging and discharging processes. This characteristic contributes to achieving a high breakdown electric field (∼1.4 MV cm⁻¹). The effective energy-storage density of the Nd₂Ti₂O₇ ceramics was determined to be 6.56 J cm⁻³, and through variations in frequency and temperature during testing, excellent frequency and temperature stability were observed. Meanwhile, the dielectric constant of Nd₂Ti₂O₇ ceramics is approximately 38 at room temperature, and the forbidden bandwidth is estimated to be approximately 3.76 eV through spectroscopic techniques. Further, the average density of the samples was able to reach ∼6.073 g cm⁻³. The perovskite-type Nd₂Ti₂O₇ ceramics present favorable prospects for applications in the development of pulse dielectric capacitors.

Flexible mechano-optical sensors (FMOS) achieve quantitative sensing of mechanical stimuli by monitoring changes in optical response, and due to the incorporation of a polymeric matrix/substrate, they exhibit high flexibility, elasticity, and biocompatibility. This wireless and visualized sensing capability offers potential for both in situ and in vivo applications. In this review, we delve into the mechanisms and developments of two types of FMOS: “active” mechanoluminescence (ML) and “passive” mechanoplasmonics (MP). The focus is on how ML particles and polymers can be combined in various configurations (such as bulk, laminar, and woven blending systems) to yield robust, multifunctional, and hybrid optical/electrical properties, exploring their potentials in engineering, information, and wearable/implantable applications. Additionally, the tunability of ML intensity and emission color under mechanical and various environmental stimuli is summarized, leading to a discussion on the versatile MP nanostructures. With their sophisticated artificial design, MP demonstrates promise for both small-scale sensing and high-level control over spectral wavelength and intensity. Lastly, based on current research on ML and MP, challenges and prospects for combining these two technologies to advance the field of FMOS are proposed.

With the rapid advancements of communication technology, developing multifunctional thermally conductive materials is crucial to addressing future heat management challenges. In this study, highly thermally conductive PPENK/PVP modified BN (PPENK/MBN) multilayer nanocomposite films inspired by wafer biscuits were constructed through a simple and efficient strategy. Verified by X-ray microscopy (XRM), the designed wafer biscuit-like structure provided abundant internal heat conduction pathways. As a result, the PPENK/MBN nanocomposite films with 39.2 wt% MBN content exhibited in-plane and out-of-plane thermal conductivities of 9.66 W m⁻¹ K⁻¹ and 1.13 W m⁻¹ K⁻¹, respectively, as well as excellent dielectric properties with a dielectric constant of 3.51 and a dielectric loss value as low as 0.010@15 GHz. Furthermore, the composites demonstrated a high thermal decomposition temperature of 511.3 °C. This study lays a foundation for the preparation of high thermal conductivity nanocomposites and provides possible applications in thermal management.

The emerging two-dimensional (2D) material tellurium (Te) is a promising material for polarization-sensitive photodetectors (PDs) due to its narrow bandgap and inherent in-plane anisotropic crystal structure. However, the shortened photocarrier lifetime and large dark current due to the ultra-narrow bandgap and intrinsically high conductivity of Te limit the performance of photodetectors and hinder their further application in photodetection. In this paper, a Te/MXene structure was prepared by spin coating of 2D Ti₃C₂–MXene on the 2D Te nanosheets (NTs) via a hydrothermal method. The Te/MXene Schottky junction PD enables polarization-sensitive, self-powered and broadband photodetection and imaging. The device exhibits a self-powered optical response from 368 nm to 1006 nm, a maximum responsivity and a specific detectivity of 1.84 A W⁻¹ and 4.83 × 10¹² jones, respectively, a switching ratio of 2163, and a fast rise/decay time of 12.2/26.5 ms under 806 nm. The anisotropy ratio of the Te/MXene PD is increased to 4 in comparison to 1.8 of the Te PD, suggesting a notable 2222% improvement in polarization sensitivity features. Due to the in-plane low-symmetry atomic structure of the Te NTs and high absorption capacity of MXene, the fabricated high Te/MXene Schottky junction fast separates the electronic carriers to show excellent properties and polarization sensitivity. The process of creating this novel photodetector may offer a viable way to expand the use of polarization-sensitive photoelectric devices in the future.

Magnetism has been recently considered to be of great significance in boosting the hydrogen evolution reaction (HER) activity. In order to investigate the catalytic role of magnetism in the HER, numerous efforts mostly focus on doping magnetic elements in catalysts. However, some interfering factors such as strain and hybridization inevitably appear in this approach, which is not conducive to the study of the intrinsic relationship between magnetism and the HER. In this work, we propose a Pd thin film with thickness-dependent magnetism to explore the magnetism–activity correlation for the HER, significantly avoiding the interference of other factors. Our first-principles results show only the ferromagnetic 4 and 9 (monolayer) ML Pd films exhibit better HER activity than the nonmagnetic films with adjacent thickness, with a ΔG_H* value of −0.108 eV and −0.132 eV, respectively. The results revealed that it is the ferromagnetism of the Pd active site that weakens the strength of hydrogen adsorption and improves the amount of electron transfer, thereby resulting in enhanced magnetic HER activity. Hence, our work provides direct evidence for magnetism-improved HER activity, opening up new possibilities for the rational design and modulation of high-performance catalysts for the HER.

The quest for lead-free materials capable of emitting white light has been a focal point in the realm of luminescent materials due to their potential applications in lighting and display technologies. This study presents a novel approach to achieving broadband white-light emission through the doping of Ag⁺ in the zero-dimensional (0D) lead-free inorganic metal halide Cs₂InCl₅·H₂O (CICH), and the strategic addition of H₃PO₂ (HPA) to facilitate the substitution of Ag⁺ for In³⁺. The PL spectra revealed that the emission intensity and the corresponding lifetime of the Ag⁺-doped CICH samples increased with Ag⁺ concentration, reaching a maximum at 7% Ag⁺ doping. This enhancement is attributed to the suppression of non-radiative recombination and the enhancement of self-trapped exciton (STE) emission, which is a direct result of the structural deformation induced by Ag⁺ substitution for In³⁺. The large Stokes shift of 255 nm and the long luminescence lifetime of 20.56 μs observed in the optimized sample S7-CICH:Ag⁺ underscore the high quality of the STE emission. The significance of this research lies in the development of a new class of lead-free luminescent materials that combine high efficiency, broad emission, and thermal stability.

Carbon-based materials, known for their green sustainability and high specific surface area, have long been favored as electrode materials with commercial prospects. However, they often fall short of delivering the expected performance in areas such as electrical conductivity and cycle stability. This paper reports a porous carbon material formed by combining NaCl crystals and citric acid. Relying on the hard template configuration, the molten pore-forming of NaCl crystals causes the citric acid base material to produce disordered porous carbon. Structural characterization and performance testing reveal that after high-temperature carbonization, the material generates numerous mesopores due to the evaporation etching of NaCl and has amorphous carbon with a highly disordered and dense structure. The resulting high specific surface area and abundant defects endow it with highly efficient electrochemical performance. Moreover, an enhanced specific capacitance of 81 F g⁻¹ at a current density of 0.5 A g⁻¹ and high capacitance retention rate of 98% after 60 000 cycles of the synthesized supercapacitor were obtained. This research offers a new avenue for the development of green energy and the design of electrode materials with commercial potential.

Controlling the morphology of bulk heterojunction (BHJ) films, which are the optoelectrical active layer, in all-polymer solar cells (all-PSCs) is both delicate and challenging in the pursuit of high-performance organic solar cells. In this study, we achieved improvement in the efficiency of all-PSCs by integrating two straightforward processes. First, we induced appropriate pre-aggregation by adding a polar solvent additive to a polymer solution. Subsequently, an external electric field was applied to the polymer film to promote crystal expansion. This combination approach differs from the previously reported BHJ film morphology control processes by leveraging the polarity differences between the donor and acceptor materials to selectively enhance crystallinity. The active materials used were PTB7-Th as the donor and P(NDI2OD-T2) as the acceptor, and acetonitrile (ACN) was applied as a polar solvent additive. As a result, suitable aggregation differences led to an interpenetrated structure, forming a well-defined fibrillar morphology. This structure facilitated the creation of an efficient charge transport pathway, resulting in increased short-circuit current (J_SC) and fill factor (FF). Consequently, a 35.7% increase in power conversion efficiency (PCE) was achieved. This study is significant as it demonstrates the effective control of the morphology of BHJ films through the application of a novel combination of two processes.