Ultrahigh Surface Area Nanoporous Carbons Synthesized via Hypergolic and Activation Reactions for Enhanced CO Capacity and Volumetric Energy Density.

We report a family of carbon sorbents synthesized by integrating hypergolics with activation reactions on a templated substrate. The materials design leads to nanoporous carbons with a BET area of 4800 m g with an impressive total pore volume of 2.7 cm g.

Graphene Nanobeacons with High-Affinity Pockets for Combined, Selective, and Effective Decontamination and Reagentless Detection of Heavy Metals.

Access to clean water for drinking, sanitation, and irrigation is a major sustainable development goal of the United Nations. Thus, technologies for cleaning water and quality-monitoring must become widely accessible and of low-cost, while being effective, selective, sustainable, and eco-friendly. To meet this challenge, hetero-bifunctional nanographene fluorescent beacons with high-affinity pockets for heavy metals are developed, offering top-rated and selective adsorption for cadmium and lead, reaching 870 and 450 mg g , respectively.

Graphene Oxide-Cytochrome c Multilayered Structures for Biocatalytic Applications: Decrypting the Role of Surfactant in Langmuir-Schaefer Layer Deposition.

Graphene, a two-dimensional single-layer carbon allotrope, has attracted tremendous scientific interest due to its outstanding physicochemical properties. Its monatomic thickness, high specific surface area, and chemical stability render it an ideal building block for the development of well-ordered layered nanostructures with tailored properties. Herein, biohybrid graphene-based layer-by-layer structures are prepared by means of conventional and surfactant-assisted Langmuir-Schaefer layer deposition techniques, whereby cytochrome c molecules are accommodated within ordered layers of graphene oxide.

Intracellular Trafficking of Cationic Carbon Dots in Cancer Cell Lines MCF-7 and HeLa-Time Lapse Microscopy, Concentration-Dependent Uptake, Viability, DNA Damage, and Cell Cycle Profile.

Fluorescent carbon dots (CDs) are potential tools for the labeling of cells with many advantages such as photostability, multicolor emission, small size, rapid uptake, biocompatibility, and easy preparation. Affinity towards organelles can be influenced by the surface properties of CDs which affect the interaction with the cell and cytoplasmic distribution. Organelle targeting by carbon dots is promising for anticancer treatment; thus, intracellular trafficking and cytotoxicity of cationic CDs was investigated.

Self-Targeting of Carbon Dots into the Cell Nucleus: Diverse Mechanisms of Toxicity in NIH/3T3 and L929 Cells.

It is important to understand the nanomaterials intracellular trafficking and distribution and investigate their targeting into the nuclear area in the living cells. In our previous study, we firstly observed penetration of nonmodified positively charged carbon dots decorated with quaternary ammonium groups (QCDs) into the nucleus of mouse NIH/3T3 fibroblasts. Thus, in this work, we focused on deeper study of QCDs distribution inside two healthy mouse NIH/3T3 and L929 cell lines by fluorescence microspectroscopy and performed a comprehensive cytotoxic and DNA damage measurements.

Carbon Nanostructures Derived through Hypergolic Reaction of Conductive Polymers with Fuming Nitric Acid at Ambient Conditions.

Hypergolic systems rely on organic fuel and a powerful oxidizer that spontaneously ignites upon contact without any external ignition source. Although their main utilization pertains to rocket fuels and propellants, it is only recently that hypergolics has been established from our group as a new general method for the synthesis of different morphologies of carbon nanostructures depending on the hypergolic pair (organic fuel-oxidizer). In search of new pairs, the hypergolic mixture described here contains polyaniline as the organic source of carbon and fuming nitric acid as strong oxidizer.

Nanocarbon from Rocket Fuel Waste: The Case of Furfuryl Alcohol-Fuming Nitric Acid Hypergolic Pair.

In hypergolics two substances ignite spontaneously upon contact without external aid. Although the concept mostly applies to rocket fuels and propellants, it is only recently that hypergolics has been recognized from our group as a radically new methodology towards carbon materials synthesis. Comparatively to other preparative methods, hypergolics allows the rapid and spontaneous formation of carbon at ambient conditions in an exothermic manner (e.

Advanced Cr(VI) sorption properties of activated carbon produced via pyrolysis of the "Posidonia oceanica" seagrass.

This research deals with the removal of Cr(VI), one of the most toxic heavy metal in biological systems, from wastewater by using activated carbon produced via pyrolysis and chemical activation of "Posidonia oceanica". That is the most important and well-studied seagrass species of the Mediterranean Sea. The as produced activated carbon exhibited high specific surface area up to 1563 m/g and a cumulative pore volume of 0.

Rapid Carbon Formation from Spontaneous Reaction of Ferrocene and Liquid Bromine at Ambient Conditions.

Herein, we present an interesting route to carbon derived from ferrocene without pyrolysis. Specifically, the direct contact of the metallocene with liquid bromine at ambient conditions released rapidly and spontaneously carbon soot, the latter containing dense spheres, nanosheets, and hollow spheres. The derived carbon carried surface C-Br bonds that permitted postfunctionalization of the solid through nucleophilic substitution.

Hypergolics in Carbon Nanomaterials Synthesis: New Paradigms and Perspectives.

Recently we have highlighted the importance of hypergolic reactions in carbon materials synthesis. In an effort to expand this topic with additional new paradigms, herein we present novel preparations of carbon nanomaterials, such-like carbon nanosheets and fullerols (hydroxylated fullerenes), through spontaneous ignition of coffee-sodium peroxide (NaO) and C-NaO hypergolic mixtures, respectively. In these cases, coffee and fullerenes played the role of the combustible fuel, whereas sodium peroxide the role of the strong oxidizer (e.

Functional Carbon Materials Derived through Hypergolic Reactions at Ambient Conditions.

Carbon formation from organic precursors is an energy-consuming process that often requires the heating of a precursor in an oven at elevated temperature. In this paper, we present a conceptually different synthesis pathway for functional carbon materials based on hypergolic mixtures, i.e.

Thiophenol-Modified Fluorographene Derivatives for Nonlinear Optical Applications.

The synthesis and characterization of two thiophenol-modified fluorographene derivatives, namely methoxythiophenol-and dimethylaminothiophenol-modified fluorographenes, are reported, while their third-order nonlinear optical response were thoroughly investigated under both visible (532 nm) and infrared (1064 nm) with 35 ps and 4 ns laser pulses. The graphene derivatives were obtained by partial nucleophilic substitution/reduction of fluorographene by the corresponding organic thiophenols, and were fully characterized by techniques including infrared/Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force spectroscopy, and high-resolution transmission microscopy. This type of modification resulted in graphenic structures where the attached thiol groups, sp domains, and the residual fluorine groups act as donors, π bridges, and acceptors, respectively.

Synthesis of Highly Crystalline Graphite from Spontaneous Ignition of In Situ Derived Acetylene and Chlorine at Ambient Conditions.

We exploited a classic chemistry demonstration experiment based on the reaction of acetylene with chlorine to obtain highly crystalline graphite at ambient conditions. Acetylene and chlorine were generated in-situ by the addition of calcium carbide (CaC) in a concentrated HCl solution, followed by the quick addition of domestic bleach (NaClO). The released gases reacted spontaneously, giving bursts of yellow flame, leaving highly crystalline graphite deposits in the aqueous phase.

Graphene/Carbon Dot Hybrid Thin Films Prepared by a Modified Langmuir-Schaefer Method.

The special electronic, optical, thermal, and mechanical properties of graphene resulting from its 2D nature, as well as the ease of functionalizing it through a simple acid treatment, make graphene an ideal building block for the development of new hybrid nanostructures with well-defined dimensions and behavior. Such hybrids have great potential as active materials in applications such as gas storage, gas/liquid separation, photocatalysis, bioimaging, optoelectronics, and nanosensing. In this study, luminescent carbon dots (C-dots) were sandwiched between oxidized graphene sheets to form novel hybrid multilayer films.

Room temperature organic magnets derived from sp functionalized graphene.

Materials based on metallic elements that have d orbitals and exhibit room temperature magnetism have been known for centuries and applied in a huge range of technologies. Development of room temperature carbon magnets containing exclusively sp orbitals is viewed as great challenge in chemistry, physics, spintronics and materials science. Here we describe a series of room temperature organic magnets prepared by a simple and controllable route based on the substitution of fluorine atoms in fluorographene with hydroxyl groups.

Cyanographene and Graphene Acid: Emerging Derivatives Enabling High-Yield and Selective Functionalization of Graphene.

Efficient and selective methods for covalent derivatization of graphene are needed because they enable tuning of graphene's surface and electronic properties, thus expanding its application potential. However, existing approaches based mainly on chemistry of graphene and graphene oxide achieve only limited level of functionalization due to chemical inertness of the surface and nonselective simultaneous attachment of different functional groups, respectively. Here we present a conceptually different route based on synthesis of cyanographene via the controllable substitution and defluorination of fluorographene.

Noncovalent Functionalization of Graphene and Graphene Oxide for Energy Materials, Biosensing, Catalytic, and Biomedical Applications.

This Review focuses on noncovalent functionalization of graphene and graphene oxide with various species involving biomolecules, polymers, drugs, metals and metal oxide-based nanoparticles, quantum dots, magnetic nanostructures, other carbon allotropes (fullerenes, nanodiamonds, and carbon nanotubes), and graphene analogues (MoS2, WS2). A brief description of π-π interactions, van der Waals forces, ionic interactions, and hydrogen bonding allowing noncovalent modification of graphene and graphene oxide is first given. The main part of this Review is devoted to tailored functionalization for applications in drug delivery, energy materials, solar cells, water splitting, biosensing, bioimaging, environmental, catalytic, photocatalytic, and biomedical technologies.

Thiofluorographene-hydrophilic graphene derivative with semiconducting and genosensing properties.

We present the first example of covalent chemistry on fluorographene, enabling the attachment of -SH groups through nucleophilic substitution of fluorine in a polar solvent. The resulting thiographene-like, 2D derivative is hydrophilic with semiconducting properties and bandgap between 1 and 2 eV depending on F/SH ratio. Thiofluorographene is applied in DNA biosensing by electrochemical impedance spectroscopy.

Third-order nonlinear optical response and optical limiting of colloidal carbon dots.

In this work, the nonlinear optical response of some organophilic and hydrophilic carbon dots derived from gallate precursors is studied under 4 ns and 35 ps, visible (532 nm) and infrared (1064 nm) laser excitation conditions by the Z-scan technique. The prepared carbon dots were found to exhibit considerable nonlinear optical response in the visible, the organophilic ones exhibiting stronger response in the infrared and, in general, significantly larger response than their hydrophilic counterparts. In all cases, the corresponding nonlinear optical parameters have been determined.

A functionalized phosphonate-rich organosilica layered hybrid material (PSLM) fabricated through a mild process for heavy metal uptake.

A phosphonate-rich organosilica layered hybrid material (PSLM) made of 3-(trihydroxysilyl)propyl methylphosphonate, monosodium salt, as the single silica source, has been obtained from its aqueous solution through a xerogel process and mild thermal aging. The method is simple, affording bulk quantities of powdered PSLM in a single-step. The hybrid is stable in water and possesses a high content of phosphonate groups fixed on the solid matrix.

Tuning the dispersibility of carbon nanostructures from organophilic to hydrophilic: towards the preparation of new multipurpose carbon-based hybrids.

The hydroxyphenyl derivatives of carbon nanostructures (graphene and carbon nanotubes) can be easily transformed into highly organophilic or hydrophilic derivatives by using the ionic interactions between the phenolic groups and oleylamine or tetramethylammonium hydroxide, respectively. The products were finely dispersed in homo-polymers or block co-polymers to create homogeneous carbon-based nanocomposites and were used as nanocarriers for the dispersion and protection of strongly hydrophobic compounds, such as large aromatic chromophores or anticancer drugs in aqueous solutions.

Graphene fluoride: a stable stoichiometric graphene derivative and its chemical conversion to graphene.

Stoichoimetric graphene fluoride monolayers are obtained in a single step by the liquid-phase exfoliation of graphite fluoride with sulfolane. Comparative quantum-mechanical calculations reveal that graphene fluoride is the most thermodynamically stable of five studied hypothetical graphene derivatives; graphane, graphene fluoride, bromide, chloride, and iodide. The graphene fluoride is transformed into graphene via graphene iodide, a spontaneously decomposing intermediate.

Fullerol ionic fluids.

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol).