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Recent advances in two-dimensional (2D) materials have led to the renewed interest in intercalation as a powerful fabrication and processing tool. Intercalation is an effective method of modifying the interlayer interactions, doping 2D materials, modifying their electronic structure or even converting them into starkly different new structures or phases. Herein, we discuss different methods of intercalation and provide a comprehensive review of various roles and applications of intercalation in next‐generation energy storage, optoelectronics, thermoelectrics, catalysis, etc. The recent progress in intercalation effects on crystal structure and structural phase transitions, including the emergence of quantum phases are also reviewed.

Since its first fabrication by exfoliation in 2014, phosphorene has been the focus of rapidly expanding research activities. The number of phosphorene publications has been increasing at a rate exceeding that of other two-dimensional materials. This tremendous level of excitement arises from the unique properties of phosphorene, including its puckered layer structure. With its widely tunable band gap, strong in-plane anisotropy, and high carrier mobility, phosphorene is at the center of numerous fundamental studies and applications spanning from electronic, optoelectronic, and spintronic devices to sensors, actuators, and thermoelectrics to energy conversion, and storage devices. Here, we review the most significant recent studies in the field of phosphorene research and technology. Our focus is on the synthesis and layer number determination, anisotropic properties, tuning of the band gap and related properties, strain engineering, and applications in electronics, thermoelectrics, and energy storage. The current needs and likely future research directions for phosphorene are also discussed.

In this study, we present a detailed investigation of the structural evolution of NMC111 (LiNi1/3Mn1/3Co1/3O2) cathode material during cycling over an extended potential window, using a combination of in situ and ex situ Raman spectroscopy, ex situ X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HR-TEM). The in situ Raman spectroscopy enabled real-time monitoring of structural changes under operating conditions, while ex situ Raman provided a more detailed post-mortem analysis. We revealed an energy-dependent Raman response that offered further insights into the electronic band structure and phase transitions within the material. We also observed a significant surface layer reconstruction at high potentials, where the NMC111 layered structure transitions into a cubic phase. This surface layer transformation is reversible during the initial stages of cycling but contributes to irreversible degradation with extended cycling, especially at elevated voltages. Ex situ XRD was employed to study the bulk structural evolution of NMC111, confirming that conventional XRD effectively captures large-scale structural changes during cycling, including significant volume variations. Additionally, TEM imaging revealed stress fringes in relithiated grains, indicating cycling-induced stress accumulation from unit cell changes and revealing particle cracking mechanism due to repeated volume fluctuations. This complete analysis provided a complementary view of both surface and bulk modifications, illustrating the advantages of integrating multiple characterization techniques. It offers valuable insights into the mechanisms behind the capacity fading, cracking of the material, and performance loss observed in lithium-ion batteries with NMC cathodes. This comprehensive understanding is essential for improving the design and performance of such batteries, particularly for high-voltage operation.

Background When a fluorophore is placed in the vicinity of a metal nanoparticle possessing a strong plasmon field, its fluorescence emission may change extensively. Our study is to better understand this phenomenon and predict the extent of quenching and/or enhancement of fluorescence, to beneficially utilize it in molecular sensing/imaging. Results Plasmon field intensities on/around gold nanoparticles (GNPs) with various diameters were theoretically computed with respect to the distance from the GNP surface. The field intensity decreased rapidly with the distance from the surface and the rate of decrease was greater for the particle with a smaller diameter. Using the plasmon field strength obtained, the level of fluorescence alternation by the field was theoretically estimated. For experimental studies, 10 nm GNPs were coated with polymer layer(s) of known thicknesses. Cypate, a near infrared fluorophore, was placed on the outermost layer of the polymer coated GNPs, artificially separated from the GNP at known distances, and its fluorescence levels were observed. The fluorescence of Cypate on the particle surface was quenched almost completely and, at approximately 5 nm from the surface, it was enhanced ~17 times. The level decreased thereafter. Theoretically computed fluorescence levels of the Cypate placed at various distances from a 10 nm GNP were compared with the experimental data. The trend of the resulting fluorescence was similar. The experimental results, however, showed greater enhancement than the theoretical estimates, in general. The distance from the GNP surface that showed the maximum enhancement in the experiment was greater than the one theoretically predicted, probably due to the difference in the two systems. Conclusions Factors affecting the fluorescence of a fluorophore placed near a GNP are the GNP size, coating material on GNP, wavelengths of the incident light and emitted light and intrinsic quantum yield of the fluorophore. Experimentally, we were able to quench and enhance the fluorescence of Cypate, by changing the distance between the fluorophore and GNP. This ability of artificially controlling fluorescence can be beneficially used in developing contrast agents for highly sensitive and specific optical sensing and imaging.

In this paper, the application of a microsphere-based fiber-optic sensor with a 200 nm zinc oxide (ZnO) coating, deposited by the Atomic Layer Deposition (ALD) method, for temperature measurements between 100 and 300 °C, is presented. The main advantage of integrating a fiber-optic microsphere with a sensing device is the possibility of monitoring the integrity of the sensor head in real-time, which allows for higher accuracy during measurements. The study has demonstrated that ZnO ALD-coated microsphere-based sensors can be successfully used for temperature measurements. The sensitivity of the tested device was found to be 103.5 nW/°C when the sensor was coupled with a light source of 1300 nm central wavelength. The measured coefficient R2 of the sensor head was over 0.99, indicating a good fit of the theoretical linear model to the measured experimental data.

Photocatalytic polymers offer an alternative to prevailing organometallics and nanomaterials, and they may benefit from polymer-mediated catalytic and material enhancements. MPC-1 , a polymer photoredox catalyst reported herein, exhibits enhanced catalytic activity arising from charge transfer states (CTSs) between its two chromophores. Oligomeric and polymeric MPC-1 preparations both promote efficient hydrodehalogenation of α -halocarbonyl compounds while exhibiting different solubility properties. The polymer is readily recovered by filtration. MPC-1 -coated vessels enable batch and flow photocatalysis, even with opaque reaction mixtures, via “backside irradiation.” Ultrafast transient absorption spectroscopy indicates a fast charge-transfer process within 20 ps of photoexcitation. Time-resolved photoluminescence measurements reveal an approximate 10 ns lifetime for bright valence states. Ultrafast measurements suggest a long CTS lifetime. Empirical catalytic activities of small-molecule models of MPC-1 subunits support the CTS hypothesis. Density functional theory (DFT) and time-dependent DFT calculations are in good agreement with experimental spectra, spectral peak assignment, and proposed underlying energetics. While photoredox catalysis offers a new dimension to chemical synthesis, there are few heterogeneous organocatalysts for metal-free transformations. Here, authors prepare and perform in-depth studies on polymeric photocatalyst scaffolds for organic chemistry transformations.

Graphite’s capacity of intercalating lithium in rechargeable batteries is limited (theoretically, 372 mAh g −1 ) due to low diffusion within commensurately-stacked graphene layers. Graphene foam with highly enriched incommensurately-stacked layers was grown and applied as an active electrode in rechargeable batteries. A 93% incommensurate graphene foam demonstrated a reversible specific capacity of 1,540 mAh g −1 with a 75% coulombic efficiency, and an 86% incommensurate sample achieves above 99% coulombic efficiency exhibiting 930 mAh g −1 specific capacity. The structural and binding analysis of graphene show that lithium atoms highly intercalate within weakly interacting incommensurately-stacked graphene network, followed by a further flexible rearrangement of layers for a long-term stable cycling. We consider lithium intercalation model for multilayer graphene where capacity varies with N number of layers resulting Li N+1 C 2N stoichiometry. The effective capacity of commonly used carbon-based rechargeable batteries can be significantly improved using incommensurate graphene as an anode material.

In this study, we investigate the influence of cold-plasma-induced enhanced performance and efficiency of SAPO-34 membranes in the separation of CO2 and CH4 mixtures. Placing the herein presented research in a broader context, we aim to address the question of whether cold plasma can significantly impact the membrane performance. We subjected SAPO-34 membranes to plasma mild disturbances and analyzed their performance in separating CO2 and CH4. Our findings reveal a notable enhancement in membrane efficiency and sustained performance when exposed to cold plasma. The pulsed plasma separation displayed improved structural integrity, and the experimental results indicated that the linear structure of CO₂ facilitates the distortion of electron clouds in response to the electric field, a property known as polarizability, which aids in effective separation. Plausible mechanistic insight indicated that the intermolecular forces facilitated an integral role in SAPO-34 membranes exhibiting strong electrostatic interactions. In conclusion, our research highlights the potential of cold plasma as a promising technique for improving the performance of SAPO-34 membranes in gas mixtures at atmospheric pressures, providing valuable insights for optimizing membrane technology in carbon capture and gas separation applications.

Phosphorene nanoribbons (PNRs) have inspired strong research interests to explore their exciting properties that are associated with the unique two‐dimensional (2D) structure of phosphorene as well as the additional quantum confinement of the nanoribbon morphology, providing new materials strategy for electronic and optoelectronic applications. Despite several important properties of PNRs, the production of these structures with narrow widths is still a great challenge. Here, a facile and straightforward approach to synthesize PNRs via an electrochemical process that utilize the anisotropic Na+ diffusion barrier in black phosphorus (BP) along the [001] zigzag direction against the [100] armchair direction, is reported. The produced PNRs display widths of good uniformity (10.3 ± 3.8 nm) observed by high‐resolution transmission electron microscopy, and the suppressed B2g vibrational mode from Raman spectroscopy results. More interestingly, when used in field‐effect transistors, synthesized bundles exhibit the n‐type behavior, which is dramatically different from bulk BP flakes which are p‐type. This work provides insights into a new synthesis approach of PNRs with confined widths, paving the way toward the development of phosphorene and other highly anisotropic nanoribbon materials for high‐quality electronic applications. Black phosphorous (BP) flakes are nanostructured via electrochemical intercalation of Na+ ions into bundles of phosphorene nanoribbons (PNRs). The large diffusion barrier of Na+ ions along the armchair direction leads to a well‐defined columnar intercalation of Na+ ions in BP, resulting in zigzag‐oriented columns of disordered material and PNRs in‐between. The sonication is then used to separate the PNRs.

Van der Waals layered magnetic materials have recently received significant attention for their ability to exhibit antiferromagnetic or ferromagnetic (FM) properties, even at the few-layer or monolayer scale. Among them, Fe3GeTe2 is one of the most extensively studied systems, crystallizing in a hexagonal structure as an itinerant FM with a Curie temperature (TC) of ∼220 K in bulk form and strong magnetic anisotropy. In this study, temperature and magnetic field dependence of the four-probe resistance ( Rxx),  thermopower (TEP) (S), and Hall resistance ( Rxy) were investigated in thick Fe3GeTe2 flakes with different thicknesses to understand electron and spin transport, as well as spin and magnetic states. Rxx decreased with decreasing temperature, confirming metallic behavior, consistent with the observed reduction in the magnitude of the negative TEP. Negative magnetoresistance (MR) with the magnetic field normal to the sample plane exhibited a quadratic field dependence below TC. An anomalous Hall effect was observed below TC, where Rxy(B ) showed a linear field dependence at low fields and saturation at higher fields. The anomalous Hall resistance ( RxyA) followed a dependence of αRxx+βRxx2. A positive in-plane MR was observed when the current was perpendicular to the magnetic field, attributed to increased scattering from the enhanced Lorentz force and related orbital effects. Additionally, a hysteresis behavior was observed when cycling the in-plane magnetic field, likely due to the delay in domain alignment in response to the changing field.