Application Of 2D Nanomaterials Research Articles

Mechanical, thermal, and electrical properties of 2D nanomaterials for advanced applications

The rapid development of two-dimensional (2D) Nanomaterials, primarily graphene-based nanoplates or nanosheets, hexagonal boron nitride (hBN), dichalcogenides of transition metals (TMDs), MXenes, metal-/covalent- organic frameworks, (MOFs/COFs) over the last decade has been driven by the great success of graphene. Despite their high similarity in lattice structure, the uniqueness of their specific atomic arrangement gives rise to phenomenal properties such as electrical, mechanical, and thermal, and thus finds a broad array of applications in electronics, optoelectronics, energy storage devices, solar cells, composites, manufacturing, and so on. This paper majorly focuses on the various properties of 2D Nanomaterials including electrical, mechanical, and thermal properties. Due to the promising properties of 2D Nanomaterials, various applications of 2D Nanomaterials are highlighted. The future outlook of 2D Nanomaterials has also been discussed.

MoS2 Quantum Dots-based Low-cost and Disposable Electrochemical Sensor for the Detection of Lead (II) Ions

After the discovery of graphene, two-dimensional (2D) nanomaterials have received great attention due to their excellent physico-chemical properties. Application of 2D-nanomaterials as receptors of a sensor can achieve high sensitivity and specificity as every atom of the material directly interacts with the analyte. In the present work, MoS2 quantum dots (MSQD) for the ultrasensitive electrochemical detection of lead (Pb2+) ions. MSQDs were prepared by mechanical shear exfoliation method. Size of the QDs and inter planar distance of the crystalline QDs were studied using transmission electron microscope (TEM). The prepared quantum dots were drop casted on a shiny surface of well-polished pencil graphite electrode (PGE). In order to obtain the highest sensitivity for Pb2+-ion sensing, anodic stripping DPV (ASDPV) was employed and consequently, the effect of pH, deposition potential and time were optimized. The sensor shows a linear range from 5.66 10−9 M to 491.93 10−9 M with a calculated detection limit 1.96 10−9 M for the detection of Pb2+-ion. The sensor’s response for Pb2+-ion was unaffected in the presence of any other metal ions. A remarkable average recovery percentage around 99.50% from the Pb2+-ion spiked agriculture soil and ground water samples proves the practical applicability of the sensor.

Exploring 2D Energy Storage Materials: Advances in Structure, Synthesis, Optimization Strategies, and Applications for Monovalent and Multivalent Metal-Ion Hybrid Capacitors.

The design and development of advanced energy storage devices with good energy/power densities and remarkable cycle life has long been a research hotspot. Metal-ion hybrid capacitors (MHCs) are considered as emerging and highly prospective candidates deriving from the integrated merits of metal-ion batteries with high energy density and supercapacitors with excellent power output and cycling stability. The realization of high-performance MHCs needs to conquer the inevitable imbalance in reaction kinetics between anode and cathode with different energy storage mechanisms. Featured by large specific surface area, short ion diffusion distance, ameliorated in-plane charge transport kinetics, and tunable surface and/or interlayer structures, 2D nanomaterials provide a promising platform for manufacturing battery-type electrodes with improved rate capability and capacitor-type electrodes with high capacity. In this article, the fundamental science of 2D nanomaterials and MHCs is first presented in detail, and then the performance optimization strategies from electrodes and electrolytes of MHCs are summarized. Next, the most recent progress in the application of 2D nanomaterials in monovalent and multivalent MHCs is dealt with. Furthermore, the energy storage mechanism of 2D electrode materials is deeply explored by advanced characterization techniques. Finally, the opportunities and challenges of 2D nanomaterials-based MHCs are prospected.

Deep Learning-Based Layer Identification of 2D Nanomaterials

Two-dimensional (2D) nanomaterials exhibit unique properties due to their low dimensionality, which has led to great potential for applications in biopharmaceuticals, aerospace, energy storage, mobile communications and other fields. Today, 2D nanomaterials are often prepared and exfoliated by a combination of mechanical and manual methods, which makes the production of 2D nanomaterials inefficient and prevents standardized and industrialized manufacturing. Recent breakthroughs in semantic segmentation techniques based on deep learning have enabled the accurate identification and segmentation of atomic layers of 2D nanomaterials using optical microscopy. In this study, we analyzed in detail sixteen semantic segmentation models that perform well on public datasets and apply them to the layer identification and segmentation of graphene and molybdenum disulfide. Furthermore, we improved the U2-Net† model to obtain the best overall performance, namely 2DU2-Net†. The accuracy of the 2DU2-Net† model was 99.03%, the kappa coefficient was 95.72%, the dice coefficient was 96.97%, and the average cross–merge ratio was 94.18%. Meanwhile, it also had good performance in terms of computation, number of parameters, inference speed and generalization ability. The results show that deep learning-based semantic segmentation methods can greatly improve efficiency and replace most manual operations, and different types of semantic segmentation methods can be adapted to different properties of 2D nanomaterials, thus promoting the research and application of 2D nanomaterials.

The physio-chemical properties and applications of 2D nanomaterials in agricultural and environmental sustainability.

Global hunger and nutritional deficiency demand the advancement of existing and conventional approaches to food production. The application of nanoenabled strategies in agriculture has opened up new avenues for enhancing crop yield and productivity. Recently, two-dimensional (2D) nanomaterials (NMs) have manifested new possibilities for increasing food production and nutrition. Graphene nanosheets, the 2D form of graphene has been exemplary in enhancing the loading capacity of agro-active ingredients, their target-specific delivery, bioavailability, and controlled release with slow degradation, resulting in the increased shelf-life/active time of the agro-active components. Also, the development of novel formulations/composites of MXenes and Transition Metal Dichalcogenides (TMDs) can foster plant growth, metabolism, crop production, protection and improvement of soil quality. Additionally, the 2D NM-based biosensors can monitor the nutrient levels and other parameters affecting agronomical traits in plants. This review provides an insight into the details of 2D NM synthesis and functionalization methods. Notably, the review highlights the broad-range of 2D NM applications and their suitability in the development of nanotechnology-based agriformulations. The 2D NM-based derivatives have shown immense potential in enhancing the pedologic parameters, crop productivity, pest-protection and nutritional value. Thus, assisting in achieving food and environmental sustainability goals.

Zirconium-Based Metal–Organic Framework and Ti3C2Tx Nanosheet-Based Faraday Cage-Type Electrochemical Aptasensor for Escherichia coli Detection

A Faraday-cage-type electrochemical aptasensor based on two-dimensional (2D) nanomaterials was developed for the sensitive detection of Escherichia coli O157:H7. In this electrochemical aptasensor, 2D titanium carbide (Ti3C2Tx) MXene was used for electrode modification. 2D Ti3C2Tx could immobilize aptamers via chelation between titanium and phosphate groups and provide a large electroactive surface for signal transduction. Another 2D zirconium ferrocene-based metal–organic framework (Zr-Fc MOF) combined with gold nanoparticles (AuNPs) and 4-mercaptophenylboronic acid (4-MPBA) (Zr-Fc MOF/AuNPs/4-MPBA) was used as an electrochemical signal label, in which Fc was a signal molecule and AuNPs could improve the electroactivity and combine with 4-MPBA via Au–S bonds. 4-MPBA could bind with E. coli O157:H7 via covalent bonding between boronic acid and the cis-diol of lipopolysaccharides on bacteria cell walls. So, the signal labels could immobilize on the electrode to form a Faraday-cage-type structure owing to the large surface area of Zr-Fc MOF. In this structure, electrons flowed directly between the electrode and ferrocene, and the electrochemical signal could be amplified. When the application of 2D nanomaterials and the Faraday-cage strategy were combined, E. coli O157:H7 was sensitively detected with a detection limit of 3 CFU·mL–1. The aptasensor was applied for milk sample detection. This aptasensor has practical application potential because of its properties of satisfactory sensitivity, specificity, and stability.

Advances and Prospects of Self-Assembly of Nanomaterials in 1D to 4D via Electrospinning

Self-assembly is a ubiquitous process in the natural environment, and electrospinning is a simple and convenient method to fabricate nanofibers. The self-assembly of electrospun nanofibers can produce nanomaterials in one-dimension (1D), two-dimension (2D), three-dimension (3D), and even four-dimension (4D). Techniques to fabricate 1D nanomaterials have been reviewed in this paper, especially for nanofiber and nanotube. The mechanism of the fabrication of 2D nanomaterials has been also introduced which is a specific arrangement of 1D nanostructures. The applications of 2D nanomaterials have been reviewed concerning energy devices, electronic devices, and biomedicine. Additionally, 3D nanomaterials, as more complex materials, are mainly utilized in tissue engineering and some in other fields. The advantages have been highlighted to suggest the development and prospect of 4D nanomaterials. Although 4D printing technologies still remain intractable, some aspects of improvement through electrospinning are possible in terms of responsive materials and self-growth materials.

Recent Progress on Two-dimensional Electrocatalysis

Due to their unique electronic and structural properties triggered by high atomic utilization and easy surface modification, two-dimensional(2D) materials have prodigious potential in electrocatalysis for energy conversion technology in recent years. In this review, we discuss the recent progress on two-dimensional nanomaterials for electrocatalysis. Five categories including metals, transition metal compounds, non-metal, metal-organic framework and other emerging 2D nanomaterials are successively introduced. Finally, the challenges and future development directions of 2D materials for electrocatalysis are also prospected. We hope this review may be helpful for guiding the design and application of 2D nanomaterials in energy conversion technologies.

Solution‐Processed Silicane Field‐Effect Transistor: Operation Due to Stacking Defects on the Channel

Abstract2D silicon nanomaterials have unique potential for use in applications owing to their many different exotic electronic properties. Field‐effect transistors are fabricated based on free‐standing silicanes through a solution process. Owing to the sensitive surface and the nanometer thickness, the devices require the use of fabrication conditions similar to those of lithium‐ion batteries to prevent oxidation of the sheets. Reliable transistor performance is observed at room temperature in a channel thinner than 3 nm, as drain voltage dependent transfer curves current modulation, depending on the edge effect of the silicane, although the transistor property is modest (hole mobility of 1.8 cm2 V−1 s−1). The results suggest the feasibility of other air‐sensitive 2D nanomaterials for applications in nanoelectronic devices.

Recent Advances of 2D Nanomaterials in the Electrode Materials of Lithium-Ion Batteries

The upcoming energy crisis and the increasing power requirements of electronic devices have drawn enormous attention to research in the field of energy storage. Owing to compelling electrochemical and mechanical properties, two-dimensional nanomaterials can be used as electrodes on lithium-ion batteries to obtain high capacity and long cycle life. This review summarized the recent advances in the application of 2D nanomaterials on the electrode materials of lithium-ion batteries.