Probing Electronic Doping in CVD Graphene Crystals Treated by HNO Vapors.

In this work, we present a comprehensive protocol for achieving hole doping in graphene through exposure to nitric acid (HNO) vapors. We demonstrate gradual p-type surface doping of CVD-grown graphene on a Si/SiO substrate by thermally depositing nitric acid molecules to form self-assembled charge transfer complexes. Detailed analysis of charge carrier concentration and Fermi energy shifts was conducted using Raman, X-ray and ultraviolet photoelectron spectroscopies (XPS/UPS).

Composition-Regulated Photocatalytic Activity of ZnInS@CdS Hybrids for Efficient Dye Degradation and HO Evolution.

Heterostructures of visible light-absorbing semiconductors were prepared through the growth of ZnInS crystallites in the presence of CdS nanostructures. A variety of hybrid compositions was synthesized. Both reference samples and heterostructured materials were characterized in detail, regarding their morphology, crystalline character, chemical speciation, as well as vibrational properties.

Highly Efficient Simulated Solar Light-Driven Photocatalytic Degradation of 4-Nitrophenol over CdS/Carbon/MoS Hybrids.

Among the various organic pollutants and industrial chemicals, 4-nitrophenol has been one of the most monitored substances in aqueous environments, due to its enhanced solubility in such systems. This research reports for the first time the microwave-assisted synthesis of CdS/carbon/MoS hybrids and the subsequent utilization of such systems as photocatalysts for 4-nitrophenol degradation. The hybrids demonstrated a variable photocatalytic activity, by using a variety of organic substances as precursors for the solvothermal carbonization step.

Mechanical, Electrical, and Thermal Properties of Carbon Nanotube Buckypapers/Epoxy Nanocomposites Produced by Oxidized and Epoxidized Nanotubes.

High volume fraction carbon nanotube (CNT) composites (7.5-16% vol.) were fabricated by the impregnation of CNT buckypapers into epoxy resin.

Rapid Microwave-Assisted Synthesis of CdS/Graphene/MoS Tunable Heterojunctions and Their Application in Photocatalysis.

Nanoscale two-dimensional nanostructures have shown great potential as functional components in photocatalysis. Here, investigations on the synthesis of heterostructured hybrids, comprised of 0D CdS nanoparticles as semiconductor and 2D/2D graphene/MoS as co-catalyst, are reported. The approach involves a rapid microwave-assisted reaction in autoclave conditions, by adopting either a one-step or a two-step protocol.

Template synthesis of defect-rich MoS-based assemblies as electrocatalytic platforms for hydrogen evolution reaction.

Defect-rich MoS2 nanostructures were synthesized in solution by a microwave-assisted process, employing either a sacrificial soft template (CaCO3) or a non-sacrificial hard template (graphene oxide) and the electrocatalytic performance towards the hydrogen evolution reaction was found to be superior for the latter.

Ionizable Star Copolymer-Assisted Graphene Phase Transfer between Immiscible Liquids: Organic Solvent/Water/Ionic Liquid.

The present study reports on the development of a simple two-step process toward the isolation of nearly defect-free mono- and few-layer graphenes in various media. This was achieved by liquid phase pre-exfoliation of pristine graphite in the presence of an ionizable PSP2VP heteroarm star copolymer in an organic solvent and subsequent graphene shuttle between immiscible media, that is, organic solvent/water and water/ionic liquid. This polymer-assisted phase transfer of graphene sheets gave rise to enrichment of suspended nanostructures in monolayers, especially in an aqueous environment.

Structural Properties of Chemically Functionalized Carbon Nanotube Thin Films.

Buckypapers are thin sheets of randomly entangled carbon nanotubes, which are highly porous networks. They are strong candidates for a number of applications, such as reinforcing materials for composites. In this work, buckypapers were produced from multiwall carbon nanotubes, pre-treated by two different chemical processes, either an oxidation or an epoxidation reaction.

Diameter-selective solubilization of carbon nanotubes by lipid micelles.

The one-step dispersion of HiPco single-walled carbon nanotubes in aqueous media with the use of a synthetic lyso-phosphatidylcholine was studied. Solubilization occurs through wrapping of lipid molecules around the circumference of the tubes, yielding lipid monolayers on the graphitic sidewalls as evidenced by atomic force microscopy imaging and dynamic light scattering measurements. Raman spectroscopy showed that the dispersion and centrifugation process leads to an effective enrichment of the stable aqueous suspension in carbon nanostructures with smaller diameters.

Colloidal stability of carbon nanotubes in an aqueous dispersion of phospholipid.

Within the family of nanomaterials, carbon nanotubes (CNTs) have emerged as a new efficient scaffold for studying molecular interactions at interfaces. Poor dispersability of CNTs in any solvent presents a considerable drawback for the development of novel functional composite structures. Previous studies have demonstrated that the solubility of CNTs can be greatly enhanced by employing appropriate surfactants, some of them being biological molecules.

Anion recognition by functionalized single wall carbon nanotubes.

Amidoferrocenyl-functionalised single wall carbon nanotubes (Fc-SWNT) are efficient exoreceptors for the redox recognition of H2PO4-.

Soluble carbon nanotubes.

Carbon nanotubes have attracted great interdisciplinary interest because of their unique structure and properties. However, carbon-nanotube research is challenged by several problems, such as: i) mass production of material, ii) control of length, diameter, and chirality, and iii) manipulation for use in diverse technological fields. Issues regarding the synthesis and purification as well as the functionalization and solubilization of carbon nanotubes are relevant topics in this rapidly growing field.