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The exponential rise in the use of LIBs raises concerns over the supply chain of critical metals, e.g., Li, Co, and Ni, used in their cathodes. Deep Eutectic Solvents (DES) are considered as green lixiviants for hydrometallurgical recycling of cathodes to recover these metals, although their efficiencies are still not at par with conventionally used harsh inorganic solvents. Here it is demonstrated that when assisted by microwave, a choline chloride (ChCl): ethylene glycol (EG) based DES shows ultrafast selective extraction of Li from different commercially used cathode compositions, with a leaching efficiency of >50% in just 30 s and nearly 100% in ≈ 30 min. The ultrafast selective Li leaching can be attributed to microwave irradiation‐induced preferential non‐thermal activation of the polar ChCl in the DES. The rapid microwave approach allows time and energy‐efficient recovery of Li and also prevents the degradation of DES, as is seen in conventional prolonged high‐temperature procedures, and is able to extract Li from high solid/liquid concentrations of LIB cathodes in DES. [ABSTRACT FROM AUTHOR]

Grand challenges facing humanity today are closely linked to the rapid exhaustion of natural resources in conjunction with the massive growth of industrial production that sustains the booming world population. The processing of animal skin waste to create collagen-based materials has the potential to provide an eco-friendly method to develop multifunctional materials such as films, sponges/scaffolds, fibers, gels, etc., that could contribute to technological advancements in different sectors. Hence in this review, we present methods for potential improvements in the development of collagen-based materials from a materials science perspective. We explored different possible approaches for utilizing collagen to generate multifunctional materials that exhibit outstanding properties, in combination with mechanical robustness and chemical stability. In sum, this review will present collagen as an eco-friendly resource that can be used to produce multifunctional, recyclable, biocompatible, and biodegradable materials that are ideal for new technologies in materials science, biomedicine, and environmental remediation. [ABSTRACT FROM AUTHOR]

Layer-by-layer stacking or lateral interfacing of atomic monolayers has opened up unprecedented opportunities to engineer two-dimensional heteromaterials. Fabrication of such artificial heterostructures with atomically clean and sharp interfaces, however, is challenging. Here, we report a one-step growth strategy for the creation of high-quality vertically stacked as well as in-plane interconnected heterostructures of WS2/MoS2 via control of the growth temperature. Vertically stacked bilayers with WS2 epitaxially grown on top of the MoS2 monolayer are formed with preferred stacking order at high temperature. A strong interlayer excitonic transition is observed due to the type II band alignment and to the clean interface of these bilayers. Vapour growth at low temperature, on the other hand, leads to lateral epitaxy of WS2 on MoS2 edges, creating seamless and atomically sharp in-plane heterostructures that generate strong localized photoluminescence enhancement and intrinsic p-n junctions. The fabrication of heterostructures from monolayers, using simple and scalable growth, paves the way for the creation of unprecedented two-dimensional materials with exciting properties. [ABSTRACT FROM AUTHOR]

Inthis work a self-assembly technique is presented, allowing thefast formation of carbon black thin films. It consists in the controlledaddition of a stable carbon material’s dispersion over thewater surface, disturbed by a vortex. The vortex, although not essentialfor the film formation, was found to drastically improve film homogeneity.A physical chemical study concerning how several parameters couldbe used to tune film properties was also conducted. The self-assembledfilms, which can be picked up in any hydrophilic substrate, showeda good electrical conductivity and a high optical transparency. Asan application example, films about 200 nm thick were employed assupercapacitor electrodes. [ABSTRACT FROM AUTHOR]

Carbon nanotube reinforced polymer composites have been extensively researched [Shadler LS, Giannaris SC, Ajayan PM (1998) Appl Phys Lett 73:3842; Ajayan PM, Shadler LS, Giannaris C, Rubio A (2000) Adv Mater 12:750; Wagner HD, Lourie O, Feldman Y, Tenne R (1998) Appl Phys Lett 72:188; Thostenson ET, Chou T-W (2002) J Phys D: Appl Phys 35:L77] for their strength and stiffness properties. The interfaces between nanotubes and polymer matrix can play a critical role in nanocomposites for their mechanical properties, since the interfacial area is order of magnitude more than traditional composites. Unless the interface is carefully engineered, poor load transfer between individual nanotubes (in bundles) and between nanotubes and surrounding polymer chains may result in interfacial slippage [Shadler et al. (1998); Ajayan et al. (2000)] and consequently disappointing mechanical stiffness and strength. Interfacial slippage, while detrimental to high stiffness and strength, could result in very high mechanical damping, which is a hugely important attribute in many commercial applications. In this paper, we show that the mechanical damping is related to frictional energy dissipation during interfacial sliding at the extremely many nanotube-polymer interfaces, and characterize the impact of activation of the frictional sliding on damping behavior. [ABSTRACT FROM AUTHOR]

Over the last few decades, research thrust in the growth and engineering of high quality atomically smooth epitaxial thin films have increased tremendously, displaying unprecedented quantum correlated phenomena and ample potential for oxitronics. Regardless of the significant progress made thus far, the growth of high quality defect-free atomically smooth epitaxial conducting perovskite oxide thin films continues to be a very active area of research, as several intrinsic and/or extrinsic factors affect the film quality and consequent electronic properties. Here, we made efforts to summarize the progress made with focus on the growth of atomically smooth electronic quality epitaxial thin films of several highly conducting ABO3 perovskites with low resistivity (high conductivity). Concomitantly, optimization of growth parameters (kinetics and thermodynamics of the material) and the film–substrate interaction seems to play a crucial role in epitaxy quality. Highly conducting epitaxial oxide thin films are pivotal in bridging the gap between oxides and the practicalities in integrating them for electronics. [ABSTRACT FROM AUTHOR]

High energy density carbon-neutral electrochemical systems are highly sought after for next-generation energy technologies, and lithium-oxygen (Li–O 2) battery occupies a unique position in them. Here, we report the development of a high capacity (9000 mAh g−1), long-term cyclability (>60 cycles), low-cost (iron and carbon) catalyst based non-aqueous Li–O 2 battery and unravel the role of the catalyst's porosity and structure in the battery performance. A scalable catalyst, named FeN x C y (S/S), is shown as the bifunctional catalyst at the cathode of the cell, where FeN x C y (S/S) has a unique structure constituted by nitrogen doped iron carbide nanoparticles decorated graphitic carbon spheres connected via graphitic sheets. The mechanism of the growth of discharged product in correlation with the high surface area and meso-porosity in FeN x C y (S/S) are studied using in situ Raman and ex situ XRD studies. The study shows the potential of Li–O 2 batteries as low-cost energy systems having high energy density (2920 Wh kg Li2O2 −1) and power density (18 mW cm−2) values that are close to their theoretical limits. [Display omitted] [ABSTRACT FROM AUTHOR]

Ternary metal sulfides (TMSs) have garnered significant attention as alternative electrode materials for rechargeable metal‐ion battery anodes and electrodes for electrochemical supercapacitors (SCs). With the escalating costs of lithium, research has shifted toward alternative sources like sodium‐ion batteries (NIBs) and potassium‐ion batteries (KIBs), offering cost‐effectiveness and greater natural abundance globally. However, pursuing suitable electrode materials beyond lithium‐ion batteries (LIBs), such as NIBs, KIBs, and SCs with enhanced energy and power density, remains a formidable challenge. In this context, TMSs demonstrate remarkable reversibility as NIB, KIB, and SC electrode materials, showcasing multi‐electron redox reactions, improved electronic conductivity, and higher theoretical capacities. Numerous research articles have highlighted the promising future of TMSs as electrodes for electrochemical energy conversion and storage (EECS). Nonetheless, practical applications are hindered by limitations, including structural stability during long‐standing cyclability, electronic conductivity, and scalability. This review systematically demonstrates how varying synthesis routes can tailor nanostructures and their influence on electrochemical activity. Additionally, an in‐depth literature survey is provided on the electrochemical performances of TMSs in NIBs, KIBs, and SCs and summarize recent advancements with the best available literature. Moreover, promising prospects and challenges are highlighted, expressing optimism that TMSs will emerge as pivotal electrodes for EECS. [ABSTRACT FROM AUTHOR]

In this work, we synthesized mixed-phase hexagonal-boron nitride (h-BN)/cubic-BN (c-BN) composites with varying ratios and investigated their frequency and temperature-dependent dielectric properties. As the ratio of c-BN increased, we observed a corresponding increase in the dielectric constant of the composites. Furthermore, we used spark-plasma sintering (SPS) to treat the mixed-phase composite, which resulted in a phase transformation from mixed phase to pure h-BN phase. Remarkably, the composite exhibited an increase in dielectric constant after the SPS process, which can be attributed to the densification of the composite and the enhancement in grain size. Our approach presents a promising strategy for effectively modulating the dielectric properties of BN, which is crucial for advanced electronics. [ABSTRACT FROM AUTHOR]

[Display omitted] Two-dimensional (2D) van der Waals (vdW) heterostructures offer new platforms for exploring novel physics and diverse applications ranging from electronics and photonics to optoelectronics at the nanoscale. The studies to date have largely focused on transition-metal dichalcogenides (TMDCs) based samples prepared by mechanical exfoliation method, therefore it is of significant interests to study high-quality vdW heterostructures using novel materials prepared by a versatile method. Here, we report a two-step vapor phase growth process for the creation of high-quality vdW heterostructures based on perovskites and TMDCs, such as 2D Cs 3 Bi 2 I 9 /MoSe 2 , with a large lattice mismatch. Supported by experimental and theoretical investigations, we discover that the Cs 3 Bi 2 I 9 /MoSe 2 vdW heterostructure possesses hybrid band alignments consisting of type-I and type-II heterojunctions because of the existence of defect energy levels in Cs 3 Bi 2 I 9. More importantly, we demonstrate that the type-II heterojunction in the Cs 3 Bi 2 I 9 /MoSe 2 vdW heterostructure not only shows a higher interlayer exciton density, but also exhibits a longer interlayer exciton lifetime than traditional 2D TMDCs based type-II heterostructures. We attribute this phenomenon to the reduced overlap of electron and hole wavefunctions caused by the large lattice mismatch. Our work demonstrates that it is possible to directly grow high-quality vdW heterostructures based on entirely different materials which provide promising platforms for exploring novel physics and cutting-edge applications, such as optoelectronics, valleytronics, and high-temperature superfluidity. [ABSTRACT FROM AUTHOR]

The article discusses how cunning refinements can improve electron transport in polycrystalline graphene by pushing the boundaries and the sizes of the grains. Researchers are facing challenges in the nucleation stage and growth of the material on metal surfaces like copper. Several approaches that affect the creation of large single crystals are also discuss such as using polycrystalline copper, surface energy minimization, and the electronic properties of graphene.

The article presents questions and answers related to carbon nanotube composites. One person asks the composition of carbon nanotubes which makes it special compared with other reinforcing fibres. Another questions the innovations which has been made to enhance the interfacial properties of nanotubes. A reader asks the applications by which nanotube composites could be used.

Optical absorption of thin-film single-walled carbon nanotubes was investigated. The excitation energies were tailored by controlling the film thickness and the average nanotube diameter. The lowest absorption band (S1, peaked at ∼0.68 eV) moves toward higher energy with increasing nanotube film thickness linearly at 5.5 meV/μm, due to the band-gap increase of stretched nanotubes stacked in the film. A subsequent heating of nanotube films at 400°C in air could further shift the S1 band upward for over 35 meV. We created a tandem structure by combining multiple nanotube layers with different diameter distributions in order to define a particular excitation energy. Our nanotube thin films are macrodevices with tunable optical properties in optoelectronic and photonic applications. [ABSTRACT FROM AUTHOR]

The race to decarbonize our energy systems has led to significant advancement in technologies for harvesting renewable energy, carbon capture and conversion. Future scenarios are being envisioned where CO2 is captured from air and converted to valuable fuels and chemicals, with methanol (MeOH) being the most coveted product. Here we assess transition pathways for the sustainable production of MeOH using CO2via direct air capture (DAC) and hybrid power via renewable photovoltaic (PV) and grid electricity. Specifically, we perform techno-economic and life-cycle analysis on technologically mature 1st generation (water electrolysis coupled to CO2 hydrogenation) and emerging 2nd generation air-to-MeOH (direct CO2-to-MeOH electrolysis) routes. Our results indicate that the two transition pathways would be economically compelling only in jurisdictions where low-cost ($0.02 per kWh) grid electricity is available. Furthermore, the economic feasibility of the 1st generation route will also depend on a drastic reduction in Si-PV ($300 per kW) and DAC ($280 per ton-CO2 per year) capital costs. On the other hand, the 2nd generation route will additionally need drastic performance improvement to be economically competitive, with required CO2 electrolysis current densities >300 mA cm−2, energy efficiency >50% and stack stability >2 years. The envisioned air-to-MeOH routes could lead to zero or negative CO2 emissions in jurisdictions with clean grid electricity (<50 kg-CO2 per MWh). We hope this study will garner key stakeholders to advance discussions about the cost and potential of this envisioned air-to-fuel technology. [ABSTRACT FROM AUTHOR]

Egg waste is a major contributor to global food waste, accounting for 15% of discarded food in the United States. Typically, eggs have a shorter shelf life at room temperature and are preserved in refrigeration from production to consumption. However, maintaining constant refrigeration is energy‐intensive and expensive. Here, a bionanocomposite coating has been developed that incorporates each element of eggs – egg white, yolk, and eggshell – to increase the shelf life of fresh eggs without requiring further refrigeration. The quality of eggs has been successfully preserved for up to three weeks at room temperature. The coated eggs maintain the highest grade (AA) and exhibit improved Haugh Unit (HU), Yolk Index (YI), and pH compared to uncoated eggs. The coating reduces weight loss by ≈37% with an increase in HU (≈12.5%) and YI (≈13.9%). Morphological analysis reveals strong adhesion of the coating to the eggshell surface, showcasing promising barrier properties. The coating demonstrates an optimal combination of oxygen permeability (≈12.2 cm3 µm m−2 d−1 kPa−1) and water vapor transmission (≈31.5 g mm m−2 per day) with excellent antimicrobial properties. Overall, this approach of repurposing eggs into a high‐performance coating shows a promising viable alternative to refrigeration and a solution to combat egg waste. [ABSTRACT FROM AUTHOR]

Many industrial processes such transesterification of fatty acid for biodiesel production, soap manufacturing and biosynthesis of ethanol generate glycerol as a major by‐product that can be used to produce commodity chemicals. Photocatalytic transformation of glycerol is an enticing approach that can exclude the need of harsh oxidants and extraneous thermal energy. However, the product yield and selectivity remain poor due to low absorption and unsymmetrical site distribution on the catalyst surface. Herein, tellurium (Te) nanorods/nanosheets (TeNRs/NSs) wrapped potassium‐doped carbon nitride (KCN) van der Waal (vdW) heterojunction (TeKCN) is designed to enhance charge separation and visible‐NIR absorption. The iridium (Ir) single atom sites decoration on the TeKCN core‐shell structure (TeKCNIr) promotes selective oxidation of glycerol to glyceraldehyde with a conversion of 45.6% and selectivity of 61.6% under AM1.5G irradiation. The catalytic selectivity can reach up to 88% under 450 nm monochromatic light. X‐ray absorption spectroscopy (XAS) demonstrates the presence of undercoordinated IrN2O2 sites which improved catalytic selectivity for glycol oxidation. Band energies and computational calculations reveal faile charge transfer in the TeKCNIr heterostructure. EPR and scavenger tests discern that superoxide (O2•−) and hydroxyl (•OH) radicals are prime components driving glycerol oxidation. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate the high performance of β-Ga2O3 metal–insulator–semiconductor (MIS) diodes. An ultrathin boron nitride (BN) interlayer is directly grown on the Ga2O3 substrate by pulsed laser deposition. X-ray photoelectron spectroscopy, Raman spectroscopy, and high-resolution transmission electron microscopy confirm the existence of a 2.8 nm BN interlayer. Remarkably, with the insertion of the ultrathin BN layer, the breakdown voltage is improved from 732 V for Ga2O3 Schottky barrier diodes to 1035 V for Ga2O3 MIS diodes owing to the passivated surface-related defects and reduced reverse leakage currents. Our approach shows a promising way to improve the breakdown performance of Ga2O3-based devices for next-generation high-power electronics. [ABSTRACT FROM AUTHOR]

Covalent Organic Frameworks (COFs) are crystalline, porous organic materials. Recent studies have demonstrated novel processing strategies for COFs to form adaptable architectures, but these have focused primarily on imine‐linked COFs. This work presents a new synthesis and processing route to produce crystalline hydrazone‐linked COF gels and aerogels with hierarchical porosity. The method was implemented to produce a series of hydrazone‐linked COFs with different alkyl side‐chain substituents, achieving control of the hydrophilicity of the final aerogel. Variation in the length of the alkyl substituents yielded materials with controllable form factors that can preferentially adsorb water or nonpolar organic solvents. Additionally, a method for additive manufacturing of hydrazone‐linked COFs using hydroxymethylcellulose as a sacrificial additive is presented. This work demonstrates an effective and simple approach to the fabrication of hydrazone COF aerogels and additive manufacturing to produce hydrazone COFs of desired shape. [ABSTRACT FROM AUTHOR]

Due to their unique properties and potential uses in many fields, composite materials have attracted much attention and been extensively investigated. We have investigated the mechanical and dielectric properties of single-walled carbon nanotubes (SWCNTs)–reinforced poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite films. Composite films were prepared with SWCNTs concentrations ranging from 0.2 to 1.0% using a solution casting technique. Impedance spectroscopy was used to investigate the composite dielectric behavior, and tensile testing was performed to examine their mechanical properties. Field emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used for morphological analyses, and an X-ray diffractometer was used to determine the crystalline phase. The results showed that adding SWCNTs improved mechanical properties, including ultimate tensile strength (UTS) and elastic modulus (E). It also increased the dielectric constant. However, the dielectric loss also increased slightly. These enhancements can be attributed to the unique characteristics of the SWCNTs, such as their high aspect ratio and surface area. This research demonstrates the potential of PVDF-HFP/SWCNTs composites in various applications such as electronic devices, sensors, and capacitors. This study offers valuable insights for developing and designing composite films with improved properties for various applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Vacancy engineering of 2H-transition metal dichalcogenides (2H-TMDs) has recently attracted great attention due to its potential to fine-tune the phonon and opto-electric properties of these materials. From a mechanical perspective, this symmetry-breaking process typically reduces the overall crack resistance of the material and adversely affects its reliability. However, vacancies can trigger the formation of heterogeneous phases that synergistically improve fracture properties. In this study, using MoSe 2 as an example, we characterize the types and density of vacancies that can emerge under electron irradiation and quantify their effect on fracture. Molecular dynamic (MD) simulations, employing a re-parameterized Tersoff potential capable of accurately capturing bond dissociation and structural phase changes, reveal that isolated transition metal monovacancies or chalcogenide divacancies tend to arrest the crack tip and hence enhance the monolayer toughness. In contrast, isolated chalcogenide monovacancies do not significantly affect toughness. The investigation further reveals that selenium vacancy lines, formed by high electron dose rates, alter the crack propagating direction and lead to multiple crack kinking. Using atomic displacements and virial stresses together with a continuum mapping, displacement, strain, and stress fields are computed to extract mechanistic information, e.g., conditions for crack kinking and size effects in fracture events. The study also reveals the potential of specific defect patterns, "vacancy engineering," to improve the toughness of 2H-TMDs materials. [ABSTRACT FROM AUTHOR]

Using a tight-binding model and the Landauer–Büttiker formalism, we have calculated the current–voltage characteristics of a semiconducting single-walled carbon nanotube and that of a fullerene (C[sub 60])-doped carbon nanotube (peapod) structure. Our calculation shows that fullerene encapsulation in a semiconducting nanotube enhances the electrical conductivity of the nanotube, which is consistent with recent experimental measurements. We explain the increased electronic conduction in the semiconducting nanopeapod structure by analyzing the density of states of both pristine and C[sub 60]-doped nanotubes. A first-principles density functional calculation shows a significant amount of charge transfer (0.62e[sup -]) from the nanotube to C[sub 60], suggesting that holes are the primary charge carriers in the peapod. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The article reports the work of Je-Luen Li and others which explains how oxygen attacks carbon bonds to break up the atomic structure of graphite. They explain how the stress generated by the epoxy bridges, leads to unravelling of the graphite lattice. and how the oxygen atom acts as a minuscule wedge, mechanically pushing the carbon-carbon bond. Their extensive works bank on density functional theory and reportedly aids in understanding the mechanisms of oxidation at an atomic level.

Using the large maximal current density and the small diameter of carbon nanotubes, a flash memory arrangement is proposed. It makes use of the spin sensitive transport through hybrid conductor junctions. This memory contains no moving mechanical part and a single layer’s theoretical information density can reach beyond 40 Gbit/cm2. It is easy to build a three-dimensional memory structure. Then, the theoretical capacity can reach beyond 1015 bit/cm3 (1000 Terrabit/cm3), which means that a memory with 1 cm area and 1 mm thickness could have about 10 TerraByte capacity. [ABSTRACT FROM AUTHOR]

Reports on the failure of decades of research to decipher the atomic-scale mechanism by which carbon nanofibers grow out vapor. Determination of the growth of filamentous carbon in a vapor phase; Presentation of the long-awaited solutions to the mystery of nanofibre growth; Growth of the nanoscale carbon fibers through the interaction of metal-catalyst nanoparticles with hydrocarbon vapor at high temperature.

The distinguished properties of hexagonal boron nitride (h -BN), specifically its atomically smooth surface, large critical electric field, and large electronic bandgap, make it ideal for thin film microelectronics and as an ultrawide bandgap semiconductor. Owing to weak van der Waals interactions between layers, h -BN exhibits a significant degree of anisotropic thermal conductivity. The in-plane thermal conductivity of h -BN has extensively been studied, yet the only measured data of cross-plane thermal conductivity ( k ⊥ ) are for exfoliated h -BN films. Exfoliation from bulk crystals is not a sustainable method for scalable production of h -BN due to its low repeatability, low yield, poor control of sample thickness, and limitation to small areas. Thus, it is necessary to investigate the thickness-dependence of k ⊥ for thin films grown by a practical growth method, such as pulsed laser deposition (PLD), which enables the production of reliable and large-area h -BN films with a control of film thickness. We grew h -BN using PLD at 750 °C and observed a decreasing trend of k ⊥ as thickness increases from 30 to 300 nm, varying from ∼1.5 to ∼0.2 W/(m K). We observed a relatively high k ⊥ value for h -BN at a thickness of 30 nm, providing insight into the k ⊥ of PLD-grown films suitable for electronics applications. [ABSTRACT FROM AUTHOR]

Li-S batteries still suffer from two of the major challenges: polysulfide shuttle and low inherent conductivity of sulfur. Here, we report a facile way to develop a bifunctional separator coated with fluorinated multiwalled carbon nanotubes. Mild fluorination does not affect the inherent graphitic structure of carbon nanotubes as shown by transmission electron microscopy. Fluorinated carbon nanotubes show an improved capacity retention by trapping/repelling lithium polysulfides at the cathode, while simultaneously acting as the "second current collector". Moreover, reduced charge-transfer resistance and enhanced electrochemical performance at the cathode-separator interface result in a high gravimetric capacity of around 670 mAh g−1 at 4C. Unique chemical interactions between fluorine and carbon at the separator and the polysulfides, studied using DFT calculations, establish a new direction of utilizing highly electronegative fluorine moieties and absorption-based porous carbons for mitigation of polysulfide shuttle in Li-S batteries. [ABSTRACT FROM AUTHOR]

Review: 182 refs. [ABSTRACT FROM AUTHOR]

Rapid production of nanoscale carbon-based designs with complex 3D geometry has been recently enabled by nano-3D printing via two-photon polymerization (2PP) combined with post-pyrolysis of the printed polymer. Upon pyrolysis, the design is converted to predominantly carbon, but it remains critical to select the appropriate 2PP printing parameters to produce a high stiffness and strength carbon material. Herein, we evaluate the mechanical performance under both tension and compression of 2PP-derived pyrolyzed carbon designed with modified printing parameters and provide the structural insight toward creating a robust and reliable pyrolyzed carbon material. The 2PP printing parameters are found to influence the Young's modulus of the pyrolyzed carbon by the degree of graphitic sp2 bonding in the carbon while the yield strength is dictated by the degree of porosity which influences crack initiation. These mechanisms are dissimilar to the precursor polymer indicating specific design requirements for the pyrolyzed carbon. Additionally, the surface roughness of the pyrolyzed carbon is uniform and ultra-smooth regardless of the precursor polymer conditions. This article thereby provides a template and structural insight towards the creation of a reliable and robust pyrolyzed carbon material that is suitable for the wide range of nano and microscale designs enabled by this technology. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to the strong in-plane but weak out-of-plane bonding, it is relatively easy to separate nanosheets of two-dimensional (2D) materials from their respective bulk crystals. This exfoliation of 2D materials can yield large 2D nanosheets, hundreds of micrometers wide, that can be as thin as one or a few atomic layers thick. However, the underlying physical mechanisms unique to each exfoliation technique can produce a wide distribution of defects, yields, functionalization, lateral sizes, and thicknesses, which can be appropriate for specific end applications. The five most commonly used exfoliation techniques include micromechanical cleavage, ultrasonication, shear exfoliation, ball milling, and electrochemical exfoliation. In this review, we present an overview of the field of 2D material exfoliation and the underlying physical mechanisms with emphasis on progress over the last decade. The beneficial characteristics and shortcomings of each exfoliation process are discussed in the context of their functional properties to guide the selection of the best technique for a given application. Furthermore, an analysis of standard applications of exfoliated 2D nanosheets is presented including their use in energy storage, electronics, lubrication, composite, and structural applications. By providing detailed insight into the underlying exfoliation mechanisms along with the advantages and disadvantages of each technique, this review intends to guide the reader toward the appropriate batch-scale exfoliation techniques for a wide variety of industrial applications. [ABSTRACT FROM AUTHOR]

Quantifying the intrinsic mechanical properties of two-dimensional (2D) materials is essential to predict the long-term reliability of materials and systems in emerging applications ranging from energy to health to next-generation sensors and electronics. Currently, measurements of fracture toughness and identification of associated atomistic mechanisms remain challenging. Herein, we report an integrated experimental–computational framework in which in-situ high-resolution transmission electron microscopy (HRTEM) measurements of the intrinsic fracture energy of monolayer MoS2 and MoSe2 are in good agreement with atomistic model predictions based on an accurately parameterized interatomic potential. Changes in crystalline structures at the crack tip and crack edges, as observed in in-situ HRTEM crack extension tests, are properly predicted. Such a good agreement is the result of including large deformation pathways and phase transitions in the parameterization of the inter-atomic potential. The established framework emerges as a robust approach to determine the predictive capabilities of molecular dynamics models employed in the screening of 2D materials, in the spirit of the materials genome initiative. Moreover, it enables device-level predictions with superior accuracy (e.g., fatigue lifetime predictions of electro- and opto-electronic nanodevices). [ABSTRACT FROM AUTHOR]

Different aspects of CO 2 capture addressed in this review. [Display omitted] The separation and sequestration of anthropogenic CO 2 is one of the most effective steps to counter global warming by curtailing the excess CO 2 levels in the atmosphere. However, to achieve the global climate change targets, in addition to the capture of CO 2 from the point sources, complementary carbon-negative technologies that capture CO 2 directly from the atmosphere are also necessary. The most crucial aspect of any CO 2 capture technology is the selection of a suitable sorbent, which is the most efficient in a specific temperature, pressure, and moisture range. The urgent nature of the CO 2 crisis has led to overwhelming contributions from researchers globally in terms of different sorbents, measurement techniques, reactors, and processes. Additionally, to develop a commercially viable CO 2 capture technology, a detailed and holistic techno-economic analysis is also vital. In this review, we have documented the recent progress on CO 2 capture studies using different solid sorbents under various operational conditions, along with the methodologies and reactors used for these studies. Furthermore, this review presents a detailed account of the industrial status of various existing CO 2 capture technologies, including direct air capture and its techno-economic prospects. This review aims to provide a bird's eye view of the status of CO 2 capture research with a particular emphasis on the most recent developments in this field. [ABSTRACT FROM AUTHOR]

High surface area porous carbons derived from sustainable biomass wastes are excellent functional materials for energy storage and gas sorption applications. Tasmanian Blue Gum (TBG) tree bark is selected as the raw material for preparing activated porous carbon (AC), using a simple KOH activation and carbonization method. The as-prepared AC-TBG sample possesses a hierarchically connected mesoporous structure having a surface area of 971 m2 g−1 with an average pore size of 2.2 nm. AC-TBG exhibits high electrochemical storage capacity as fabricated symmetric supercapacitor, with excellent specific capacitances of 212 F g−1 at 1 A g−1 current density retaining 90% of its capacitance after 5000 cycles. An outstanding maximum power density of 4.9 kW kg−1 was obtained for the EDLC in 1 M KOH at a maximum energy density of 18.84 Wh kg−1, which is among the highest values reported in this class of materials. Furthermore, exploiting the multiscale porosity and oxygen/hydroxyl functionalities on the surface, AC-TBG was deployed for CO 2 capture from concentrated source as well as dilute 4% CO 2 simulated flue stream. AC-TBG showed an excellent uptake of 4.5 mmol/g of CO 2 at 1 bar and 0 °C for pure CO 2 and a working capacity of 1.6 mmol/g at 40 °C in 4% CO 2. This work provides a simple, and feasible strategy for converting sustainable waste biomass to value-added activated carbon with potential applications in high-performance energy storage and greenhouse gas capture. Activated carbon derived from bark of Tasmanian Blue Gum tree shows high CO 2 uptake capacity and excellent activity and cycle life as a fabricated symmetric supercapacitor. [Display omitted] [ABSTRACT FROM AUTHOR]

Realizing solution-processed heterostructures is a long-enduring challenge in halide perovskites because of solvent incompatibilities that disrupt the underlying layer. By leveraging the solvent dielectric constant and Gutmann donor number, we could grow phase-pure two-dimensional (2D) halide perovskite stacks of the desired composition, thickness, and bandgap onto 3D perovskites without dissolving the underlying substrate. Characterization reveals a 3D-2D transition region of 20 nanometers mainly determined by the roughness of the bottom 3D layer. Thickness dependence of the 2D perovskite layer reveals the anticipated trends for n-i-p and p-i-n architectures, which is consistent with band alignment and carrier transport limits for 2D perovskites. We measured a photovoltaic efficiency of 24.5%, with exceptional stability of T99 (time required to preserve 99% of initial photovoltaic efficiency) of >2000 hours, implying that the 3D/2D bilayer inherits the intrinsic durability of 2D perovskite without compromising efficiency. [ABSTRACT FROM AUTHOR]

We have developed a continuously tunable, broadband terahertz attenuator with a transmission tuning range greater than 10³. Attenuation tuning is achieved electrically, by simply changing the DC voltage applied to a heating wire attached to a bulk silicon wafer, which controls its temperature between room temperature and ~550 K, with the corresponding free-carrier density adjusted between ~1011 cm-3 and ~ 1017cm-3 . This "hot-silicon"-based terahertz attenuator works most effectively at 450-550 K (corresponding to a DC voltage variation of only ~7 V) and completely shields terahertz radiation above 550 K in a frequency range of 0.1-2.5 THz. Both intrinsic and doped silicon wafers were tested and demonstrated to work well as a continuously tunable attenuator. All behaviors can be understood quantitatively via the free-carrier Drude model taking into account thermally activated intrinsic carriers. [ABSTRACT FROM AUTHOR]

Petroleum asphaltenes, a by-product of crude oil extraction, are a promising feedstock for the development of high-value carbonaceous materials because of their high carbon content and aromaticity. In this work, we have studied the efficacy of low-value petroleum asphaltenes as raw materials in producing carbon fibers. We present a facile, yet effective, method to produce carbon fibers without the need of expensive pre-treatment processing. To do this, extensive physicochemical characterizations were carried out to evaluate asphaltene properties throughout the entire process. Continuous spinning of green fibers with different diameters (∼10–200 μm) was optimized according to the rheological characteristics of asphaltenes. We originally developed a multi-step stabilization process to cross-link the asphaltene-derived green fibers. This was followed by carbonization of the fibers resulting in fibers with mechanical strength of ∼400 MPa and Young's modulus of ∼70 GPa. These are relatively high values obtained without any pretreatment or high temperature carbonization/graphitization. This study presents a previously unexplored avenue to develop low-cost carbon fibers from low-value petroleum asphaltenes. [Display omitted] [ABSTRACT FROM AUTHOR]

Efficient electrocatalysts are highly desirable for promising electrochemical reactions that are likely to mitigate the long‐standing energy and environment problems mainly resulting from human activities. However, most of them are partly composed by scarce and precious metals, thus hampering their large‐scale utilization. In this regard, developing efficient electrocatalysts with reduced noble metals loading or without noble metals is highly desirable. In the past decade, carbon nanotubes (CNTs)‐based electrocatalysts have proven to be efficient in many typical electrocatalytic reactions, and its strong structure operability and easy accessibility enable the utilization of related electrocatalysts to be sustainable. This review is aimed to summarize the research progress in CNTs‐based electrocatalysts, which are widely used in various electrochemical reactions. The major structure regulation approaches toward CNTs‐based electrocatalysts are highlighted. The primary functions of CNTs‐based electrocatalysts in electrochemical reactions are also highlighted here, together with the discussions on the support effect related to CNTs. Synchrotron‐based spectroscopies which can explore the intrinsic structure details that contribute to the performance enhancement and the electrochemical structure evolution of electrocatalysts under working conditions are also discussed. Finally, the challenges for shedding light on the very essence of the activity and the research perspectives are suggested. [ABSTRACT FROM AUTHOR]

Functionalized fullerene nanostructures are a distinct class of materials that exhibit the combined properties of both fullerene and nanostructures including excellent optoelectronic features, modified band edges, high electron affinity, fast charge transfer capabilities, and tunable structural and textural properties. These fascinating properties allow for their utilization in many applications such as polymer solar cells, photovoltaics, photocatalysis, photodynamic therapy, electrocatalysis, environmental remediation, and drug and gene delivery. Numerous synthesis methods and anchoring groups are employed for functionalized fullerenes with nanostructures by using convergent bottom‐up and top‐down strategies. The supramolecular self‐assembly and functionalization of fullerenes through robust chemistry approaches such as surface oxidation, grafting, polymer coating, doping of metals/nonmetal heteroatoms, noncovalent modification with 2D materials and nanoparticle attachment result in achieving fine control over its surface and bulk properties, including increased solubility, wettability, electron transport, acid–base properties, adsorption, electronic conductivity, and light absorption. This review analyzes the salient developments in the fabrication of nanostructured fullerenes and their functionalized derivatives for many applications including adsorption, catalysis, sensors, energy storage, solar cells, drug delivery, magnetic and superconducting devices. The contents of this review will allow the readers to cherish exciting possibilities and opportunities in field of functionalized nanofullerenes. [ABSTRACT FROM AUTHOR]

Background: A label-free immunosensor from as-grown double wall carbon nanotubes (DW) bundles was developed for detecting Salmonella typhimurium. The immunosensor was fabricated by using the as-grown DW bundles as an electrode material with an anti-Salmonella impregnated on the surface. The immunosensor was electrochemically characterized by cyclic voltammetry. The working potential (100, 200, 300 and 400 mV vs. Ag/AgCl) and the anti-Salmonella concentration (10, 25, 50, 75, and 100 μg/mL) at the electrode were subsequently optimized. Then, chronoamperometry was used with the optimum potential of 100 mV vs. Ag/AgCl) and the optimum impregnated anti-Salmonella of 10 μg/mL to detect S. typhimurium cells (0-109 CFU/mL). Results: The DW immunosensor exhibited a detection range of 102 to 107 CFU/mL for the bacteria with a limit of detection of 8.9 CFU/mL according to the IUPAC recommendation. The electrode also showed specificity to S. typhimurium but no current response to Escherichia coli. Conclusions: These findings suggest that the use of a label-free DW immunosensor is promising for detecting S. typhimurium. [ABSTRACT FROM AUTHOR]

[Display omitted] Reliable transfer processes that enable manipulation of two-dimensional (2D) materials, e.g., transition metal dichalcogenides (TMDCs) and MXenes, from one substrate to another has been a necessity for successful device fabrication. With both mechanical exfoliation and chemical vapor deposition (CVD) widely used, a versatile, clean, deterministic, and yet simple transfer technique is highly needed. To address such need, we developed a transfer method that takes advantage of wettability contrast between interfaces without the use of sacrificial layers or chemical processes. More importantly, a setup was developed to carry out this transfer method with high sample selectivity and fine control of the position and orientation of transferred TMDC crystals, a feature required for fabrication of the devices based on vertical 2D heterostructures. Using both exfoliated and CVD grown materials and subsequent atomic force microscopy (AFM), photoluminescence (PL), confocal Raman and tip enhanced Raman spectroscopy (TERS) characterization, we ascertained the quality of interfaces resulting from the transfer process while preserving excellent 2D material integrity. PL and TERS maps revealed nanometer-scale heterogeneities in the interfaces of fabricated heterostructures, which should enable further perfection of the transfer technique. TERS/TEPL information were employed to identify areas suitable for nanodevice fabrication, making the reported transfer and characterization methods ideal for making high quality assembly of 2D heterostructure more accessible, which should facilitate exploration of vertical 2D heterostructures for applications in electronics, batteries, solar cells, and twistronics. [ABSTRACT FROM AUTHOR]

[Display omitted] Two-dimensional (2D) materials are at the forefront of current materials research due to their exciting and unique properties. 2D tellurides are emerging materials which are yet to be fully explored. To provide an overview of this emergent field, in this review, we discuss the structure, properties, synthesis methods, and applications of selected 2D tellurides, with stoichiometry of M x Te y , and M x N y Te z , (M, N are metal atoms). We present a summary of the latest advances in modeling, experimental synthesis, and characterization of 2D tellurides. Additionally, stress and strain-induced tunability of the physical properties have been reviewed, with a focus on the application of 2D tellurides in electronic, optoelectronic, and magnetic devices. We have discussed many emergent quantum properties of these materials. Finally, we conclude with a perspective on the future of 2D metal tellurides. [ABSTRACT FROM AUTHOR]

The article offers information about the two-dimensional (2D) materials, known to have low-friction interfaces by reducing the energy dissipated by sliding contacts. It demonstrate the low-friction behavior of magnetene, a non-vdW 2D material obtained via the exfoliation of magnetite, showing statistically similar friction to benchmark vdW 2D materials.

• The critical role of carbons, including biomass-based carbon materials and their importance, highlighted. • Role of carbons and their function in batteries, supercapacitor, and Fuel cells were described. • Various strategies for boosting energy devices' performance via conductive materials are reviewed. • Several commercially available carbon-based energy systems were presented. • The current challenges and future possibilities are discussed. In recent years, several innovations and studies have been remarked to develop carbon-based nanocomposites and their applications. Carbon-based materials have received increased attention in every category, including the energy sector, water purification, and biomedical. Besides, carbon and its derivatives are well-known for their remarkable features such as high conductivity, surface area, excellent chemical, and mechanical stability. On the other hand, transitional metal oxides (TMO) and conducting polymers (CPs) are renowned for their docility, low price, and reliable performance. In general, the carbon electrodes functioning was reported to improve considerably by homogeneous blending of TMO and CPs. This approach results in developing excellent electrode material that can deliver high-performance functional composites for electrochemical energy storage systems. In this review, we discussed the synergistic effect and the resulting performance of functional carbons considering features like morphology, surface area, and other parameters that influence the activity of functional carbons and their electrochemical studies. [Display omitted] [ABSTRACT FROM AUTHOR]

Developing bactericidal coatings using simple green chemical methods could be a promising route to potential environmentally friendly applications. Here, we describe an environmentally friendly chemistry approach to synthesize metal-nanoparticle (MNP)-embedded paint, in a single step, from common household paint. The naturally occurring oxidative drying process in oils, involving free-radical exchange, was used as the fundamental mechanism for reducing metal salts and dispersing MNPs in the oil media, without the use of any external reducing or stabilizing agents. These well-dispersed MNP-in-oil dispersions can be used directly, akin to commercially available paints, on nearly all kinds of surface such as wood, glass, steel and different polymers. The surfaces coated with silver-nanoparticle paint showed excellent antimicrobial properties by killing both Gram-positive human pathogens (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The process we have developed here is quite general and can be applied in the synthesis of a variety of MNP-in-oil systems. [ABSTRACT FROM AUTHOR]

Single-slit laser diffractography was used to image the growth of carbon nanotubes. A silicon dioxide slit with a minimum width of 150 μm was prepared and positioned inside a chemical vapor deposition (CVD) reactor in alignment with a laser source. Carbon nanotubes were grown inside the slit width, producing corresponding changes in the diffraction pattern due to the optical opacity of these structures and to their high density and alignment. Changes in the diffraction pattern were recorded and used for the direct measurement of nanotube growth. The results show an exponential increase of length vs time for 45 min experiments, best fit with a double exponential function, which is interpreted in terms of the concurrence of base-growth and tip-growth modes for successive catalyst particles. Scanning electron microscopy confirms the diffractographic data at a high level of precision. The innovation brought by this in situ method to the kinetic study of nanotube synthesis is discussed and compared to a posteriori studies based solely on microscopy for a range of different nanotube lengths. [ABSTRACT FROM AUTHOR]

It is known that surface terminations contribute significantly to diamond properties. As one of the most commonly studied types, oxygen-terminated diamond surface possesses a positive electron affinity (PEA) and hydrophilicity, making it suitable for electronic device fabrication and bioapplications. Various oxidation methods have been reported on diamond, but a systematic comparison is still lacking. Herein, we present a comparative study on the oxidation of microcrystalline diamond powder (DP) and polycrystalline diamond film (PCD) by wet chemical treatments, including various acid mixtures, as well as by dry processes, including O 2 plasma and UV ozone. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) results reveal that H 2 SO 4 /HNO 3 5:1 at 360 °C demonstrates the best oxidation performance on DP and PCD compared to other wet chemical methods, while the PCD treated by O 2 plasma exhibits the highest oxygen content among all the treated samples. Besides, the concentration of carbon-oxygen groups on diamond surfaces is found largely determined by oxidation methods. These experimental results can be attributed to the corresponding oxidation mechanism of different treatments and agree well with theoretical simulations. Finally, we investigated the sp2 bonded carbon concentration and surface roughness of oxidized PCD, suggesting the optimized diamond surface cleaning conditions. [Display omitted] • This work provides a comprehensive and comparative analysis of diamond surface oxidation by various wet and dry methods. • Various oxidation treatments produce different degrees of oxidation as well as distinct proportions of oxygenated groups. • The influence of oxidation treatment on graphitization degree and surface morphology of diamond has been compared. • The experimental results can be well explained by molecular mechanical (MM) simulations. [ABSTRACT FROM AUTHOR]

Graphite, with many industrial applications, is one of the widely sought-after allotropes of carbon. Although the geometric design of the graphite in many of the applications could dictate its precision performance, conventional synthesis methods for formulating complex geometric graphite shapes are limited due to the intrinsic brittleness and difficulties of high-temperature processing. Here, we report the development of colloidal ink from commercial graphite powders that allows the fabrication of any complex architectures with tunable geometry and directionality via 3D printing at room temperature. The method is enabled via using very small amounts of clay as an additive, allowing the proper design of the graphite-based ink and subsequent binding of graphite platelets during printing. Sheared layers of clay are easily able to flow, adapt, and interface with graphite layers forming strong binding between the layers that make the larger structures. The direct ink writing of complex graphitic architectures without further heat treatments could lead to easy shape engineering and related applications of graphite at various length scales. The printed structures exhibit excellent thermal, electrical, and mechanical properties, and the clay additive does not seem to alter these properties due to the excellent inter-layer dispersion and mixing within the graphite material. [Display omitted] [ABSTRACT FROM AUTHOR]

Specific targeting of cell organelles is indispensable for bioimaging and diagnostics but remains a challenge due to the limitation of highly selective fluorescent targeting probes. Herein, we successfully designed a molecular fusion route to controllably synthesize bright orange fluorescent graphene quantum dots (GQDs). The relative nitrogen doping level of the GQDs reached 18.88 at%. The GQDs exhibited long-wavelength excitation fluorescence and photoluminescence (PL) stability. Femtosecond transient absorption spectroscopy elucidated that the sp2 cluster and the surface state's synergistic effect contributed to the PL. Furthermore, the most alluring discovery was that the GQDs had good biocompatibility and an unprecedented targeting capability for superselective nucleus imaging without staining cell organelles. Molecular dynamics simulations revealed that once the GQDs were transported across the plasma membrane, the higher the N-doping ratio of the GQDs was, and the easier the GQDs penetrated the membrane. The reason may stem from the compatibility of –NH 2 with lipid molecules, which is higher than that of –OH. Enriched nitrogen doping in GQDs is beneficial for crossing the cell membrane to the target nucleus. Our findings could provide scientific theory and a technical basis to design nucleus-targeting probes in the future. Enriched nitrogen-doping in graphene quantum dots enables a high-selective fluorescent probe for nucleus-targeting imaging. [Display omitted] • Bright orange fluorescent GQDs are controllably synthesized by a molecular fusion route. • The GQDs exhibited long-wavelength excitation fluorescence and PL stability. • The sp2 cluster and the surface state's synergistic effect contributed to the PL. • The GQDs had good biocompatibility and an unprecedented targeting capability for superselective nucleus imaging. • Enriched nitrogen doping up to 18.88 at% in GQDs is beneficial for crossing the cell membrane to the target nucleus. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have emerged as an exciting new class of porous materials constructed by organic building blocks via dynamic covalent bonds. They have been extensively explored as potentially superior candidates for electrode materials, electrolytes, and separators, due to their tunable chemistry, tailorable structures, and well‐defined pores. These features enable rational design of targeted functionalities, facilitate the penetration of electrolytes, and enhance ion transport. This review provides an in‐depth summary of the recent progress in the development of COFs for diverse battery applications, including lithium‐ion, lithium–sulfur, sodium‐ion, potassium‐ion, lithium–CO2, zinc‐ion, zinc–air batteries, etc. This comprehensive synopsis pays particular attention to the structure and chemistry of COFs and novel strategies that have been implemented to improve battery performance. Additionally, current challenges, possible solutions, and potential future research directions on COFs for batteries are discussed, laying the groundwork for future advances for this exciting class of material. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotube thin films were fabricated using catalytic chemical vapor deposition of xylene–ferrocene mixture precursor. The nanotube films were employed as inter-layers within composite systems to reinforce the interfaces between composite plies, enhancing laminate stiffness as well as structural damping. Experiments conducted using a piezo-silica composite beam with an embedded nano-film sub-layer indicated up to 200% increase in the inherent damping level and 30% increase in the baseline bending stiffness with minimal increase in structural weight. Scanning Electron Microscopy (SEM) characterization of the nano-film was also conducted to investigate the mechanics of stiffness and damping augmentation. The study revealed a fascinating network of densely packed, highly interlinked multiwalled nanotubes (MWNTs). This inter-tube connectivity resulted in strong interactions between adjacent nanotube clusters as they shear relative to each other causing energy dissipation within the nano-film. The cross-links between nanotubes also served to improve load transfer within the network resulting in improved stiffness properties. [Copyright &y& Elsevier]