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Single-walled carbon nanotubes (SWCNTs) are ideal channel material candidates for energy-efficient nanoscale transistors; however, it is challenging to achieve uniform alignment of semiconducting SWCNTs with homogeneous chirality. Here, we report the proof-of-concept of using organized chirality-sorted SWCNTs via the alignment relay technique (ART), where iptycene molecules order the nanotubes through π–π interactions. Top-gated field-effect transistors (FETs) were fabricated with aligned (10,3) chirality SWCNTs as channels to show an ION of 3.8 μA, an ION/IOFF ratio of 2.9 × 106, and a carrier mobility of 10.08 cm2/(V s), which is enhanced by two magnitudes of order compared with a bundled SWCNT network channel. In addition, the ART was applied to align commercially available semiconducting SWCNTs to fabricate a chemiresistive gas sensor that showed prompt detection of 4 ppm ammonia (NH3) with a sensitivity of 0.43 ± 0.04%/ppm, demonstrating a general approach to align SWCNTs for applications in electronic devices. [ABSTRACT FROM AUTHOR]

The chemical engineering community has shown significant interest in investigating methods to decompose hydrogen sulfide into hydrogen and sulfur. However, there is still a lack of detailed experimental data enabling us to choose the optimal catalyst, reaction, and regeneration conditions, as well as the overall process design. The purpose of this work is to synthesize a series of catalysts and compare their catalytic activity under the same conditions, chosen on the basis of a possible large-scale H2S conversion process. To achieve this, the obtained catalysts were characterized by BET, XRD, SEM, TEM, and XPS before and after the reaction. Decomposition was conducted in a laboratory fixed-bed reactor at a temperature of 500 °C, 10 vol% of H2S in the feed, and a GHSV of 540–1000 h−1. DFT calculations evaluated the H2S bond cleavage on various catalyst surfaces. It was shown that the most promising catalyst was Ni3S2, offering an acceptable H2S conversion of 40%. We also observed that Ni3S2 catalyst regeneration could be conducted at much milder conditions compared to those previously reported in the literature. These results highlight the viability of upscaling the process with the selected catalyst. [ABSTRACT FROM AUTHOR]

The use of hexagonal boron nitride (h-BN) as a material for hydrogen storage is attributed to its ability to accommodate atomic and molecular hydrogen. However, the low diffusion barrier of molecular hydrogen within the h-BN structure does not fully explain the long-term stability of hydrogen bubbles observed in experimental work [L. He, H. Wang, L. Chen, X. Wang, H. Xie, C. Jiang, C. Li, K. Elibol, J. Meyer, K. Watanabe, T. Taniguchi, Z. Wu, W. Wang, Z. Ni, X. Miao, C. Zhang, D. Zhang, H. Wang and X. Xie, Nat. Commun., 2019, 10, 2815, https://doi.org/10.1038/s41467-019-10660-9]. Another unresolved inquiry is the method by which hydrogen infiltrates the h-BN layer in a perpendicular direction. In this study, we conducted a comprehensive examination of several aspects that can impact the permeation of hydrogen in the h-BN structure. We employed DFT within the rPBE (DFT-D3(0)) functional to suggest a process for the penetration of atomic hydrogen through the h-BN sheet along the normal direction by sequential hydrogen passivation. [ABSTRACT FROM AUTHOR]

This investigation looks at the transformative potential of upcycling agricultural waste to make ecologically friendly food packaging. Agricultural wastes, which are frequently ignored, might be valuable resources in reversing the sustainable destiny of the packaging sector. We review recent research on plant-based byproducts, including proteins, polysaccharides, lipids, pigments, and minerals, that are isolated from agricultural waste. Creating edible and (bio)degradable packaging solutions that can include biobased active components, including flavorings, antioxidants, and antimicrobials, can begin with these compounds. Utilizing plant fibers from agricultural waste reduces environmental contamination while increasing packing efficiency. The review concentrates on packaging solutions that are good for the environment, like edible coatings and films with antioxidant and antibacterial qualities and active packaging made of phenolic chemicals. These innovations, derived from various foods and agricultural waste, satisfy customer demand for premium foods with longer shelf lives. A practical way to lessen the excessive use of non-biodegradable plastics is to create edible materials, especially in light of the global push for sustainability. These formulations can enhance food packaging performance since they are made from biowastes and biopolymers. Our comprehensive research synthesizes existing knowledge to shed light on the extraction, processing, and application of agricultural byproducts in packaging materials. The broad spectrum includes regulatory systems, processing techniques, biodegradability parameters, and the properties of various byproducts. By providing an all-encompassing viewpoint, this evaluation draws attention to current achievements and indicates avenues for more research and development. It provides a roadmap for the ecologically friendly upcycling of agricultural waste into sustainable food packaging, which helps to shift the packaging industry's paradigm continuously. [ABSTRACT FROM AUTHOR]

Food packaging is undergoing a revolutionary change because of nanotechnology. This paper examines the influence of nanofillers on improving food packaging materials. Due to their distinctive qualities, nanofillers like nanoparticles and nanocomposites change food product protection, preservation, and appearance. The advantages of nanofillers, which may be controlled in terms of mechanical, barrier, thermal, optical, and surface characteristics, are described in the article along with their definition. Systematic examination exposes the many functions of nanofillers, from maintaining food safety with antibacterial Nano silver to increasing shelf life with better barriers. They also support sustainability and clever packaging. Innovative applications for real-time food monitoring are investigated, along with case examples demonstrating their efficacy, including nanocomposite materials, nanosensors, and nanotags. The use of nanofillers is evaluated concerning safety, compliance, cost-effectiveness, and environmental impact. Future research trends that will influence food packaging are outlined. A critical step toward developing safer, more robust, and environmentally friendly packaging solutions is represented by nanofillers. This review is a valuable tool for anyone involved in food packaging since it provides information on disruptive technology transforming food packaging into an intelligent, environmentally friendly guardian of food quality and safety. [ABSTRACT FROM AUTHOR]

The transition to neuromorphic devices is relevant to the development of materials capable of providing electronic switching in response to external stimuli. In the present work, the Hf2CO2/MoS2 heterostructure under biaxial strain, interlayer coupling, and an electric field was investigated by first-principles calculations based on density functional theory. We have shown that the influence of lateral deformation as well as the perpendicular external electric field is more significant compared to the influence of external vertical pressure on changes in the heterojunction type of heterostructure. The lateral stretching leads to a type-I and lateral compression results in a type-II heterojunction, and an external electric field also has an effect on heterojunction type. The combination of these impacts can tune the Hf2CO2/MoS2 heterostructure. The current work suggests a compelling way to make type-I and type-II heterostructure types consisting of Hf2CO2 and MoS2 monolayers for new nanodevices in fields like photonics, electronics, optoelectronic and neuromorphic applications. [ABSTRACT FROM AUTHOR]

Here, we demonstrate an improvement in sensitivity toward the NO2 analyte by varying the width ratio of adjacent graphene oxide (GO) and reduced graphene oxide (rGO) layers using the GO laser reduction technique. We evaluated changes brought by laser reduction in material morphology, structure, electrical characteristics, and sensing performance depending on the GO/rGO ratio, which we supported by density functional theory calculations. Our results indicate that the reduction of GO yields the appearance of a chemiresistive response to NO2. An optimum GO/rGO width ratio ensures high conductivity paired with good sorption capacity, allowing to achieve chemiresistive response of 18.1% toward 100 ppm of NO2 at 25 ± 1 °C and a limit of detection of 230 ppb. The improved chemiresistive response of GO/rGO sensors upon NO2 physisorption is due to an increase in sorption energy and improved charge transfer in the presence of NO2 at the sites corresponding to the individual epoxy and hydroxyl groups at the GO/rGO interface area when compared to fully reduced GO. [ABSTRACT FROM AUTHOR]

Iron phthalocyanine-coated hexagonal boron nitride (FePc/h-BN) nanoparticles, obtained by FePcCl adsorption on the h-BN surface from a dimethylformamide solution, were subjected to heat treatment in order to form single atom Fe1/h-BN catalysts. Samples were characterized by means of X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy, and temperature-programmed oxidation/reduction/desorption. The FePc deposition process was optimized to avoid the formation of nanoparticles. FePc exhibits high thermal stability in a hydrogen atmosphere and decomposes into a single iron atom when oxidizing in an O2 flow at 350 °C (sample Fe1-ox/h-BN). Subsequent reductive heat treatment in hydrogen (sample Fe1-red/h-BN) results in the formation of Fe-based nanoparticles due to Fe1 diffusion and association, resulting in a decrease in catalytic activity. Hydrogenation proceeds according to the Eley–Rideal mechanism with CO2 chemisorption on the Fe1 surface species (Fe1-ox/h-BN) and is changed to the Langmuir–Hinshelwood mechanism (Fe1-red/h-BN). Selectivity for hydrocarbons increases after reduction of the Fe1-ox/h-BN sample. Our results open up new possibilities for using metal phthalocyanine as a precursor for cheap, reproducible, and efficient single atom catalysts for CO2 hydrogenation. [ABSTRACT FROM AUTHOR]

The growing family of two-dimensional crystals has been recognized as a promising platform for investigation of rich low-dimension physics and production of a variety of devices. Of particular interest are recently reported atomic sheets of non-van der Waals materials, which reshape our understanding of chemical bonds and enable heterostructures with novel functionality. Here, we study the structural and optical properties of ultrathin non-van der Waals InGaS3 sheets produced by standard mechanical cleavage. Our ab initio calculations reveal weak out-of-plane covalent bonds, responsible for the layered structure of the material. The energy required for isolation of a single layer is as low as ~50 meVÅ–2, which is comparable with the conventional van der Waals material's monolayer isolation energies of 20–60 meVÅ–2. A comprehensive study of the structural, vibrational, and optical properties of the material reveals its wide bandgap (2.73 eV), high refractive index (>2.5) and negligible losses in the visible and infrared spectral ranges. These properties make it a perfect candidate for visible-range all-dielectric nanophotonics. [ABSTRACT FROM AUTHOR]

Novel magnetic gas sensors are characterized by extremely high efficiency and low energy consumption, therefore, a search for a two-dimensional material suitable for room temperature magnetic gas sensors is a critical task for modern materials scientists. Here, we computationally discovered a novel ultrathin two-dimensional antiferromagnet V3S4, which, in addition to stability and remarkable electronic properties, demonstrates a great potential to be applied in magnetic gas sensing devices. Quantum-mechanical calculations within the DFT + U approach show the antiferromagnetic ground state of V3S4, which exhibits semiconducting electronic properties with a band gap of 0.36 eV. A study of electronic and magnetic response to the adsorption of various gas agents showed pronounced changes in properties with respect to the adsorption of NH3, NO2, O2, and NO molecules on the surface. The calculated energies of adsorption of these molecules were −1.25, −0.91, −0.59, and −0.93 eV, respectively. Obtained results showed the prospective for V3S4 to be used as effective sensing materials to detect NO2 and NO, for their capture, and for catalytic applications in which it is required to lower the dissociation energy of O2, for example, in oxygen reduction reactions. The sensing and reducing of NO2 and NO have great importance for improving environmental protection and sustainable development. [ABSTRACT FROM AUTHOR]