Improved Mechanical Properties of Graphene/Carbon Fiber Composites via Silanization.

Despite their excellent mechanical performance, carbon fiber-reinforced polymer (CFRP) composites are limited by the interfacial properties due to the inherent nature of laminated structures. One way to modify the interface is by the inclusion of nanomaterials. Here, we use electrochemical exfoliation to produce graphene (EEG) flakes that have hydroxyl and epoxy functional groups.

Synergistic Improvement in the Thermal Conductivity of Hybrid Boron Nitride Nanotube/Nanosheet Epoxy Composites.

Epoxy composites with excellent thermal properties are highly promising for thermal management applications in modern electronic devices. In this work, we report the enhancement of the thermal conductivity of two different nanocomposites, using epoxy resins LY564 (epoxy 1) and LY5052 (epoxy 2), by incorporating multiwalled boron nitride nanotubes (BNNT) and boron nitride nanosheets (BNNS) as fillers. The synergistic interaction between the 1D BNNT and 2D BNNS allows for improved thermal conductivity several different mechanisms.

Measuring the Capacitance of Carbon in Ionic Liquids: From Graphite to Graphene.

The physical electrochemistry of the carbon/ionic liquids interface underpins the processes occurring in a vast range of applications spanning electrochemical energy storage, iontronic devices, and lubrication. Elucidating the charge storage mechanisms at the carbon/electrolyte interface will lead to a better understanding of the operational principles of such systems. Herein, we probe the charge stored at the electrochemical double layer formed between model carbon systems, ranging from single-layer graphene to graphite and the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI).

Simultaneous Electrochemical Exfoliation and Functionalization of 2H-MoS for Supercapacitor Electrodes.

MoS is a promising semiconducting material that has been widely studied for applications in catalysis and energy storage. The covalent chemical functionalization of MoS can be used to tune the optoelectronic and chemical properties of MoS for different applications. However, 2H-MoS is typically chemically inert and difficult to functionalize directly and thus requires pretreatments such as a phase transition to 1T-MoS or argon plasma bombardment to introduce reactive defects.

Dielectric-free electrowetting on graphene.

Electrowetting is a simple way to induce the spreading and retraction of electrolyte droplets. This method is widely used in "device" applications, where a dielectric layer is applied between the electrolyte and the conducting substrate. Recent work, including contributions from our own laboratory, have shown that reversible electrowetting can be achieved directly on conductors.

Tribology of Copper Metal Matrix Composites Reinforced with Fluorinated Graphene Oxide Nanosheets: Implications for Solid Lubricants in Mechanical Switches.

The potential for the use of copper coatings on steel switching mechanisms is abundant owing to the high conductivities and corrosion resistance that they impart on the engineered assemblies. However, applications of these coatings on such moving parts are limited due to their poor tribological properties; tendencies to generate high friction and susceptibility to degradative wear. In this study, we have fabricated a fluorinated graphene oxide-copper metal matrix composite (FGO-CMMC) on an AISI 52100 bearing steel substrate by a simple electrodeposition process in water.

Deformation of and Interfacial Stress Transfer in TiC MXene-Polymer Composites.

Transitional metal carbides and nitrides (MXenes) have promise for incorporation into multifunctional composites due to their high electrical conductivity and excellent mechanical and tribological properties. It is unclear, however, to what extent MXenes are also able to improve the mechanical properties of the composites and, if so, what would be the optimal flake size and morphology. Herein, TiCT MXene is demonstrated to be indeed a good candidate for mechanical reinforcement in polymer matrices.

Investigation of Voltage Range and Self-Discharge in Aqueous Zinc-Ion Hybrid Supercapacitors.

Aqueous zinc-ion hybrid supercapacitors are a promising energy storage technology, owing to their high safety, low cost, and long-term stability. At present, however, there is a lack of understanding of the potential window and self-discharge of this aqueous energy storage technology. This study concerns a systematic investigation of the potential window of this device by cyclic voltammetry and galvanostatic charge-discharge.

Graphene-Enabled Adaptive Infrared Textiles.

Interactive clothing requires sensing and display functionalities to be embedded on textiles. Despite the significant progress of electronic textiles, the integration of optoelectronic materials on fabrics remains as an outstanding challenge. In this Letter, using the electro-optical tunability of graphene, we report adaptive optical textiles with electrically controlled reflectivity and emissivity covering the infrared and near-infrared wavelengths.

Unravelling the Mechanism of Rechargeable Aqueous Zn-MnO Batteries: Implementation of Charging Process by Electrodeposition of MnO.

Poor cycling stability and mechanistic controversies have hindered the wider application of rechargeable aqueous Zn-MnO batteries. Herein, direct evidence was provided of the importance of Mn in this type of battery by using a bespoke cell. Without pre-addition of Mn , the cell exhibited an abnormal discharge-charge profile, meaning it functioned as a primary battery.

Graphene-Based Materials as Strain Sensors in Glass Fiber/Epoxy Model Composites.

The ability of graphene-based materials to act as strain sensors in glass fiber/epoxy model composites by using Raman spectroscopy has been investigated. The strain reporting performance of two types of graphene nanoplatelets (GNPs) was compared with that of graphene produced by chemical vapor deposition (CVD). The strain sensitivity of the thicker GNPs was impeded by their limited aspect ratio and weak interaction between flakes and fibers.

3D Printing of Freestanding MXene Architectures for Current-Collector-Free Supercapacitors.

Additive manufacturing (AM) technologies appear as a paradigm for scalable manufacture of electrochemical energy storage (EES) devices, where complex 3D architectures are typically required but are hard to achieve using conventional techniques. The combination of these technologies and innovative material formulations that maximize surface area accessibility and ion transport within electrodes while minimizing space are of growing interest. Herein, aqueous inks composed of atomically thin (1-3 nm) 2D Ti C T with large lateral size of about 8 µm possessing ideal viscoelastic properties are formulated for extrusion-based 3D printing of freestanding, high specific surface area architectures to determine the viability of manufacturing energy storage devices.

Correction: Synthetic 2-D lead tin sulfide nanosheets with tuneable optoelectronic properties from a potentially scalable reaction pathway.

[This corrects the article DOI: 10.1039/C8SC04018D.].

Synthetic 2-D lead tin sulfide nanosheets with tuneable optoelectronic properties from a potentially scalable reaction pathway.

Solventless thermolysis of molecular precursors followed by liquid phase exfoliation allows access to two-dimensional IV-VI semiconductor nanomaterials hitherto unreachable by a scalable processing pathway. Firstly, the use of metal dithiocarbamate precursors to produce bulk alloys in the series Pb Sn S (0 ≤ ≤ 1) by thermolysis is demonstrated. The bulk powders are characterised by powder X-ray diffraction (pXRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy.

Capacitance of Basal Plane and Edge-Oriented Highly Ordered Pyrolytic Graphite: Specific Ion Effects.

Carbon materials are ubiquitous in energy storage; however, many of the fundamental electrochemical properties of carbons are still not fully understood. In this work, we studied the capacitance of highly ordered pyrolytic graphite (HOPG), with the aim of investigating specific ion effects seen in the capacitance of the basal plane and edge-oriented planes of the material. A series of alkali metal cations, from Li, Na, K, Rb, and Cs with chloride as the counterion, were used at a fixed electrolyte concentration.

Long-range oriented graphene-like nanosheets with corrugated structure.

A facile molten-salt (MS) route for the scalable synthesis of free-standing, long-range oriented and corrugated graphene-like sheets from a copper phthalocyanine (CuPc) precursor is reported. Their unique arrangement and transformation behavior in molten potassium chloride (KCl) play a key role in promoting the successful synthesis of the anisotropic nanostructure.

Black phosphorus with near-superhydrophobic properties and long-term stability in aqueous media.

Black phosphorus is a two-dimensional material that has potential applications in energy storage, high frequency electronics and sensing, yet it suffers from instability in oxygenated and/or aqueous systems. Here we present the use of a polymeric stabilizer which prevents the degradation of nearly 68% of the material in aqueous media over the course of ca. 1 month.

Desalination and Nanofiltration through Functionalized Laminar MoS Membranes.

Laminar membranes of two-dimensional materials are excellent candidates for applications in water filtration due to the formation of nanocapillaries between individual crystals that can exhibit a molecular and ionic sieving effect, while allowing high water flux. This approach has been exemplified previously with graphene oxide, however these membranes suffer from swelling when exposed to liquid water, leading to low salt rejection and reducing their applicability for desalination applications. Here, we demonstrate that by producing thin (∼5 μm) laminar membranes of exfoliated molybdenum disulfide (MoS) in a straightforward and scalable process, followed by a simple chemical functionalization step, we can efficiently reject ∼99% of the ions commonly found in seawater, while maintaining water fluxes significantly higher (∼5 times) than those reported for graphene oxide membranes.

Synthesis, structure and applications of graphene-based 2D heterostructures.

With the profuse amount of two-dimensional (2D) materials discovered and the improvements in their synthesis and handling, the field of 2D heterostructures has gained increased interest in recent years. Such heterostructures not only overcome the inherent limitations of each of the materials, but also allow the realization of novel properties by their proper combination. The physical and mechanical properties of graphene mean it has a prominent place in the area of 2D heterostructures.

Enhanced Photoluminescence of Solution-Exfoliated Transition Metal Dichalcogenides by Laser Etching.

Using a conventional Raman experimental apparatus, we demonstrate that the photoluminescent (PL) yield from ultrasonication-exfoliated transition metal dichalcogenides (TMDs) (MoS and WS) can be increased by up to 8-fold by means of a laser etching procedure. This laser etching process allows us to controllably pattern and reduce the number of layers of the solution-exfoliated material, overcoming the key drawback to solvent-based exfoliation of two-dimensional (2D) semiconducting materials for applications in optoelectronics. The successful laser thinning of the exfoliated 2D crystals was investigated systematically by changes in both Raman and PL spectra.

Asymmetric MoS /Graphene/Metal Sandwiches: Preparation, Characterization, and Application.

The polarizable organic/water interface is used to construct MoS /graphene nanocomposites, and various asymmetrically dual-decorated graphene sandwiches are synthesized. High-resolution transmission electron microscopy and 3D electron tomography confirm their structure. These dual-decorated graphene-based hybrids show excellent hydrogen evolution activity and promising capacitance performance.

Photoelectrochemistry of Pristine Mono- and Few-Layer MoS2.

Two-dimensional crystals are promising building blocks for the new generation of energy materials due to their low volume, high surface area, and high transparency. Electrochemical behavior of these crystals determines their performance in applications such as energy storage/conversion, sensing, and catalysis. Nevertheless, the electrochemistry of an isolated monolayer of molybdenum disulfide, which is one of the most promising semiconducting crystals, has not been achieved to date.

Characterization of MoS2-Graphene Composites for High-Performance Coin Cell Supercapacitors.

Two-dimensional materials, such as graphene and molybdenum disulfide (MoS2), can greatly increase the performance of electrochemical energy storage devices because of the combination of high surface area and electrical conductivity. Here, we have investigated the performance of solution exfoliated MoS2 thin flexible membranes as supercapacitor electrodes in a symmetrical coin cell arrangement using an aqueous electrolyte (Na2SO4). By adding highly conductive graphene to form nanocomposite membranes, it was possible to increase the specific capacitance by reducing the resistivity of the electrode and altering the morphology of the membrane.