Layered Double Hydroxide Nanosheets: Synthesis Strategies and Applications in the Field of Energy Conversion

In recent years, layered double hydroxides (LDH) nanosheets have garnered substantial attention as intriguing inorganic anionic layered clay materials. These nanosheets have captured the attention of researchers due to their unique physicochemical properties. This review aims to showcase the latest advancements in laboratory research concerning LDH nanosheets, with a specific emphasis on their methods of preparation. This review provides detailed insights into the factors influencing the anionic conductivity of LDH, along with delineating the applications of LDH nanosheets in the realm of energy conversion. Notably, the review highlights the crucial role of LDH nanosheets in the oxygen evolution reaction (OER), a vital process in water splitting and diverse electrochemical applications. The review emphasizes the significant potential of LDH nanosheets in enhancing supercapacitor technology, owing to their high surface area and exceptional charge storage capacity. Additionally, it elucidates the prospective application of LDH nanosheets as anion exchange membranes in anion exchange membrane fuel cells, potentially revolutionizing fuel cell performance through improved efficiency and stability facilitated by enhanced ion transport properties.

Ex Situ Characterization of 1T/2H MoS2 and Their Carbon Composites for Energy Applications, a Review

The growing interest in the development of next-generation net zero energy systems has led to the expansion of molybdenum disulfide (MoS₂) research in this area. This activity has resulted in a wide range of manufacturing/synthesis methods, controllable morphologies, diverse carbonaceous composite structures, a multitude of applicable characterization techniques, and multiple energy applications for MoS₂. To assess the literature trends, 37,347 MoS₂ research articles from Web of Science were text scanned to classify articles according to energy application research and characterization techniques employed. Within the review, characterization techniques are grouped under the following categories: morphology, crystal structure, composition, and chemistry. The most common characterization techniques identified through text scanning are recommended as the base fingerprint for MoS₂ samples. These include: scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Similarly, XPS and Raman spectroscopy are suggested for 2H or 1T MoS₂ phase confirmation. We provide guidance on the collection and presentation of MoS₂ characterization data. This includes how to effectively combine multiple characterization techniques, considering the sample area probed by each technique and their statistical significance, and the benefit of using reference samples. For ease of access for future experimental comparison, key numeric MoS₂ characterization values are tabulated and major literature discrepancies or currently debated characterization disputes are highlighted.

Bimetallic Metal-Organic Frameworks (BMOF) and BMOF- Incorporated Membranes for Energy and Environmental Applications

Bimetallic metal organic frameworks (BMOFs) are a class of crystalline solids and their structure comprises two metal ions in the lattice. BMOFs show a synergistic effect of two metal centres and enhanced properties compared to MOFs. By controlling the composition and relative distribution of two metal ions in the lattice the structure, morphology, and topology of BMOFs could be regulated resulting in an improvement in the tunability of pore structure, activity, and selectivity. Thus, developing BMOFs and BMOF incorporated membranes for applications such as adsorption, separation, catalysis, and sensing is a promising strategy to mitigate environmental pollution and address the looming energy crisis. Herein we present an overview of recent advancements in the area of BMOFs and a comprehensive review of BMOF incorporated membranes reported to date. The scope, challenges as well as future perspectives for BMOFs and BMOF incorporated membranes are presented.

Nata de Cassava Type of Bacterial Cellulose Doped with Phosphoric Acid as a Proton Exchange Membrane

This work aims to encourage the use of natural materials for advanced energy applications, such as proton exchange membranes in fuel cells. Herein, a new conductive membrane produced from cassava liquid waste was used to overcome environmental pollution and the global crisis of energy. The membrane was phosphorylated through a microwave-assisted method with different phosphoric acid, (H₃PO₄) concentrations (10-60 mmol). Scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), dynamic mechanical analysis (DMA), swelling behavior test, and contact angle measurement were carried out on the membrane doped with different H₃PO₄ levels. The phosphorylated NdC (nata de cassava) membrane doped with 20 mmol (NdC20) H₃PO₄ was successfully modified and significantly achieved proton conductivity (maximum conductivity up to 7.9 × 10^-2 S cm^-1 at 80 °C). In addition, the fabricated MEA was assembled using an NdC20 membrane with 60 wt% Pt/C loading of 0.5 mg cm^-2 for the anode and cathode. Results revealed that a high power density of 25 mW cm^-2 was obtained at 40 °C operating temperature for a single-cell performance test. Thus, this membrane has the potential to be used as a proton exchange membrane because it is environment-friendly and inexpensive for fuel cell applications.

Financial viability of electric vehicle lithium-ion battery recycling

Economically viable electric vehicle lithium-ion battery recycling is increasingly needed; however routes to profitability are still unclear. We present a comprehensive, holistic techno-economic model as a framework to directly compare recycling locations and processes, providing a key tool for recycling cost optimization in an international battery recycling economy. We show that recycling can be economically viable, with cost/profit ranging from (−21.43 - +21.91) $·kWh⁻¹ but strongly depends on transport distances, wages, pack design and recycling method. Comparing commercial battery packs, the Tesla Model S emerges as the most profitable, having low disassembly costs and high revenues for its cobalt. In-country recycling is suggested, to lower emissions and transportation costs and secure the materials supply chain. Our model thus enables identification of strategies for recycling profitability.

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Comprehensive techno-economic cost model for electric vehicle battery recycling

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Net recycling profits for recycling in Asia, Europe, and the US are compared

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Reducing transportation and disassembly costs is crucial for a profitable process

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Economies of scale and battery materials are decisive for recycling profits

Shock Exfoliation of Graphene Fluoride in Microwave

An unprecedented microwave-based strategy is developed to facilitate solid-phase, instantaneous delamination and decomposition of graphite fluoride (GF) into few-layer, partially fluorinated graphene. The shock reaction occurs (and completes in few seconds) under microwave irradiation upon exposing GF to either "microwave-induced plasma" generated in vacuum or "catalyst effect" caused by intense sparking of graphite at ambient conditions. A detailed analysis of the structural and compositional transformations in these processes indicates that the GF experiences considerable exfoliation and defluorination, during which sp² -bonded carbon is partially recovered despite significant structural defects being introduced. The exfoliated fluorinated graphene shows excellent electrochemical performance as anode materials in potassium ion batteries and as catalysts for the conversion of O₂ to H₂ O₂ . This simple and scalable method requires minimal energy input and does not involve the use of other chemicals, which is attractive for extensive research in fluorine-containing graphene and its derivatives in laboratories and industrial applications.

Electrospun Bimetallic NiCr Nanoparticles@Carbon Nanofibers as an Efficient Catalyst for Hydrogen Generation from Ammonia Borane

In this study, we report on the fabrication and utilization of NiCr alloy nanoparticles (NPs)-decorated carbon nanofibers (CNFs) as efficient and competent non-precious catalysts for the hydrolytic dehydrogenation of ammonia borane (AB) at 25 ± 2 °C. The introduced NFs have been fabricated in one step using a high-temperature thermal decomposition of the prepared electrospun nanofiber mats (nickel acetate tetrahydrate, chromium acetate dimer, and polyvinyl alcohol) in an inert atmosphere. The chemical composition of the NFs with different proportions of Ni_1−xCr_x (x = 0.0, 0.1, 0.15, 0.2, 0.25, 0.3) was established via standard characterization techniques. These techniques proved the formation of disorder Cr₂Ni₃ alloy and carbon for all the formulations. The as-synthesized composite NFs exhibited a higher catalytic performance for AB dehydrogenation than that of Cr-free Ni–CNFs. Among all the formulations, the sample composed of 15% Cr shows the best catalytic performance, as more H₂ was released in less time. Furthermore, it shows good stability, as it is recyclable with little decline in the catalytic activity after six cycles. It also demonstrates the activation energy, entropy (ΔS), and enthalpy (ΔH) with 37.6 kJ/mole, 0.094 kJ/mole, and 35.03 kJ/mole, respectively. Accordingly, the introduced catalyst has a lower price with higher performance encouraging a practical sustainable H₂ energy application from the chemical hydrogen storage materials.