Functionalized Carbon Nanostructures Research Articles

Functionalization of Carbon-Based Nanostructures for Environmental Remediation

The rise of environmental exploitation due to human intervention and industrialization is an alarming issue at current times. Carbon-based nanostructures have been in the application of environmental remediation due to their high sorption nature, low toxicity and other beneficial properties. Functionalization of the carbon nanostructures using relevant functional groups improves the performance of the material, which results in the target-specific application. This review focuses on the role of functionalized carbon-based nanostructures in environmental remediation. Methods of functionalization, properties, characterization and applications of those functionalized carbon nanostructures are also discussed.

Functionalized carbon nanostructures as temozolomide carriers; physicochemical and biopharmaceutical characterization

In this study, Temozolomide (TMZ), a drug used in the treatment of anaplastic astrocytoma and glioblastoma multiforme, was incorporated in multiwalled carbon nanotubes (MWCNTs) and hybrid carbon nanotubes with graphene (MWCNTs-G) functionalized by polyethylene glycol (PEG). The aim was to evaluate the potential of these nanocarriers for targeted delivery and sustained release of TMZ in brain tumor cells. Oxidized MWCNTs and MWCNTs-G were noncovalently functionalized with PEGs of different molecular weights and subsequently loaded with TMZ following standard procedures. Thorough physicochemical and biopharmaceutical characterization of the TMZ loaded carbon nanocarriers pointed to high encapsulation efficacy (up to 67%) and drug loading (up to 18% out of 25% theoretical value) and homogeneous particle size distribution, with z-average (160 to 300 nm) and zeta potential (-31 to -21 mV) of the particles adequate for crossing the blood-brain-tumor-barrier (BBTB) and entering into the tumor cells. Successful functionalization and TMZ loading were confirmed by SEM and TEM images, UV-Vis absorption, infrared and Raman spectroscopy and TGA analyses. Sustained release of TMZ from the carbon nanocarriers was observed in vitro. The presented findings form a fundamental platform for further investigation of these formulations against different types of glioma cells and in adequate animal models.

Organic Functionalized Carbon Nanostructures for Solar Energy Conversion.

This review presents an overview of the use of organic functionalized carbon nanostructures (CNSs) in solar energy conversion schemes. Our attention was focused in particular on the contribution of organic chemistry to the development of new hybrid materials that find application in dye-sensitized solar cells (DSSCs), organic photovoltaics (OPVs), and perovskite solar cells (PSCs), as well as in photocatalytic fuel production, focusing in particular on the most recent literature. The request for new materials able to accompany the green energy transition that are abundant, low-cost, low-toxicity, and made from renewable sources has further increased the interest in CNSs that meet all these requirements. The inclusion of an organic molecule, thanks to both covalent and non-covalent interactions, in a CNS leads to the development of a completely new hybrid material able of combining and improving the properties of both starting materials. In addition to the numerical data, which unequivocally state the positive effect of the new hybrid material, we hope that these examples can inspire further research in the field of photoactive materials from an organic point of view.

Chemically modified carbon nanostructures and 2D nanomaterials for fabrics performing under operational tension and extreme environmental conditions.

The extensive research on carbon nanostructures and 2D nanomaterials will come to fruition once these materials steadily join everyday-life applications. Their chemical functionalization unlocks their potential as carriers of customized properties and counterparts to fabric fibers. The scope of the current review covers the chemical modification of carbon nanostructures and 2D nanomaterials for hybrid fabrics with enhanced qualities against critical operational and weather conditions, such as antibacterial, flame retardant, UV resistant, water repellent and high air and water vapor permeability activities.

3D Atomic Understanding of Functionalized Carbon Nanostructures for Energy Applications

Functionalized carbon nanostructures have garnered significant research interest as a class of materials for a myriad of energy applications, including fuel cell catalysts, and batteries. However, ...

Carbon Nanostructure Supported Ion Exchange Platform for Efficient Electrochemical Removal of Cesium from Aqueous System

Recently, electrochemical adsorption through pre-concentration of heavy metals on the modified electrodes has been employed as a potential method for removal of heavy metals from aqueous solutions. With this perspective, a novel electrochemical separation system has been developed based on functionalized carbon nanostructures for removal of heavy metals including radionuclide from wastewater. Various carbon nanostructures were compared for their electrochemical adsorption capacity with respect to heavy metal pollutants encountered in waste water. While multi-walled carbon nanotubes and reduced graphene oxide have been explored immensely for sensing, graphitic carbon nitride is still new in the scenario. It was found to show impressive potential for heavy metal decontamination in the present study. Further, it was functionalized with an ion exchange molecule to explore the synergistic effect. This novel structure is proposed to enhance the conductivity of ion exchange molecule for efficient and speedy heavy metal decontamination with aprreciable reusability. Besides being considerably stable, it also allows electrochemical regeneration of the hybrid for subsequent use. The electrochemical adsorption/desorption system using carbon nanostructure supported ion exchange hybrid is a promising strategy for heavy metal decontamination from waste water. Figure 1

Strategies for Tuning Optoelectronic Properties of TiO2 Nanomaterials for Solar Photovoltaic Studies

Third generation solar cells are mainly focusing on the use of nanomaterials as host components for solar-to-electrical conversions. Among the various nanomaterials, TiO2 is one of the most promising candidates used in solar devices due to their remarkable structural and opto-electrical properties. However, bare TiO2 nanomaterials have the various constraints in efficient solar energy conversions. In the present research endeavors, TiO2 nanomaterials have been modified with the different strategies such as dyad anchoring, dye-quantum dot sensitization, composites of carbon nanostructures with sensitizers, metal ion doping with sensitizers so as to tune its optoelectronic properties for efficient solar energy harvesting. In addition, the interconnectivity between the various components and their optoelectronic properties of modified TiO2 for solar energy conversions have been studied in detail. In the dyad system, a supramolecular ruthenium(II)phthalocyanine··peryleneimide (RuPc···PI) has been anchored on the surfaces of TiO2 and thereafter these TiO2-dyad sensitized solar cells have assembled in a bottom-up fashion. Upon photo-irradiation at air-mass (AM) 1.5, the dyad-based solar devices convert solar light to electricity of 2.1%; which is higher than that of individual dyes. In next strategies, the synthesized CdS quantum dots (QDs) have connected electrostatically to the surfaces of TiO2 nanoparticles (NPs) and thereafter, this binary hybrid heterojunction is further self-assembled physically with N719 dye to form ternary TiO2 NPs-CdS QDs-N719 photoelectrodes. These co-sensitization devices reported the solar energy conversion efficiency (η) up to 2.35 %. In addition, anatase TiO2 NPs is anchored on the surface of functionalized carbon nanostructures (MWCNTs or RGO); which is further sensitized with Ru(II) dyes for solar devices having efficiency reached to 6.21%. In another modification, Cr(III) as well as Mo(VI) ions are inserted into TiO2 host lattice and then their composites with CNs are further sensitized for boosting the solar energy conversions and reached up to 7.69 % of efficiency. Figure 1

(Invited) Modification, Activation and Stabilization of Copper(I) Oxide Photocathodes: Competition between Catalytic and Inhibiting Effects during Light-Induced Electoreduction of CO2

Among representative examples of semiconducting materials for the selective reduction of carbon dioxide to desired small organic molecules (fuels, utility chemicals), there are transition metal oxides (p-type semiconductors), in particular Cu-based oxides, such as Cu2O, CuFeO2, CuBi2O4, CuNb2O6, CuO and Cu2O) that are capable of generating electrons with use of solar visible light. Selectivity of the catalytic systems largely depends on the activing adsorptive (CO2) phenomena and the affinity of catalytic centers to the adsorbed carbon monoxide intermediates leading to their protonation or hydrogenation. Here application of aqueous or water-containing electrolytes is generally preferred. Furthermore, a compromise must be reached between the activity of a catalyst toward hydrogen evolution (water reduction) and its ability to promote reductive adsorption of CO2 and to generate moderate coverages of H atoms capable of stabilizing subsequent reduced intermediates. Our interest concentrates on copper(I) oxides but their practical use requires means of stabilization without poisoning or deactivation. To improve stability against photocorrosion, to assure the sufficient electron-hole pair separation, as well as to increase population of electrons in the conduction band, mixed oxide systems combining the p-type semiconductor (e.g. Cu2O) with n-type semiconductors such as TiO2, SrTiO3 or KTaO3 have been proposed. To meet requirements for practical Cu2O-based photocathodes, not only the ability to absorb efficiently visible light and to assure fast interfacial electron transfers but also the stability issue needs to be addressed. Contrary to the poor performance of the pristine (bare) copper(I) oxide photocathode, the visible-light-illuminated photoelectrochemical reduction of carbon dioxide has been successfully performed using the p-type Cu2O-semiconductor (deposited onto the transparent fluorine-doped conducting glass electrode) over-coated with the ultra-thin films of various polymer (poly(4-vinyl pyridine, oligoaniline) or polynuclear type materials (titanium, zirconium and tungsten oxides).. In this respect, ultra-thin films of functionalized carbon nanostructures, supramolecular complexes (with nitrogen containing ligands and certain transition metal sites) or robust bacterial biofilms could also be advantageous. For example, the oligoaniline or tungsten oxide over-layers [1,2] have been generated on copper(I) oxide surfaces. Under such conditions, the copper(I) oxide photoelectrode does not change the oxidation state during photoelectrochemical diagnostic experiments. Thus certain robust (not necessarily thin) could exhibit the effect of stabilization of Cu2O against photocorrosion. Among important issues is the ability of CO2 to undergo adsorption (and activation toward reduction to CO) at both bare and modified surfaces of Cu2O. The proposed bi-layered photocathode has been demonstrated to produce such simple organic fuels as alcohols (mainly methanol and some ethanol). [1] Szaniawska E., Rutkowska I.A., Frik M., Wadas A., Seta E., Krogul-Sobczak A., Rajeshwar K., Kulesza P.J., Electrochim. Acta, 265, 400 (2018). [2] Rutkowska I.A., Szaniawska E., Taniewicz J., Wadas A., Seta E., Kowalski D., Kulesza P.J., J. Electrochem. Soc., 166, H3271 (2019).

Nanofilter based on functionalized carbon nanostructures for the adsorption of pentachlorophenol molecules

Increased consumption of industrialized products, medicines, and the mechanization of agribusiness have introduced new contaminants into aquatic systems. Pentachlorophenol (PCP) is a fungicide, insecticide, and bactericide that presents high human toxicity. This paper discusses the use of carbon nanostructures (CNS), such as fullerene, carbon nanotubes and graphene, as possible nanofilter platforms for PCP adsorption. The study shows electronic and structural effects of the PCP interaction on CNS through ab initio calculations. The results show that the most stable configurations of the PCP interaction with CNS exhibited a binding energy less of than 0.95 eV; the minimum distance between the atoms of the CNS and PCP was in the range of 1.7 Å; small charge transfer and negligible modifications on the electronic character of the CNS, characteristic of a physical adsorption regime. These results are very promising because they indicate the capacity for CNS to serve as a nanofilter platform.

Effect of different functionalized carbon nanostructures as fillers on the physical properties of biocompatible poly(l-lactic acid) composites

Composites of carbon nanostructures (CNSs) and biocompatible polymers are promising materials for a series of advanced technological applications, ranging from biomedicine and bioelectronics to smart packaging and soft robotics. In this work, we present three types of organic-functionalized CNSs, namely p-methoxyphenyl functionalized multi-walled carbon nanotubes, carbon nanohorns and reduced graphene oxide, used as nanofillers for the preparation of homogeneous and well-dispersed composites of poly(l-lactic acid), a biocompatible and biodegradable FDA-approved polymer. A thorough characterization of the composites is given in terms of calorimetric response, electrical and mechanical properties. Significant differences are observed among the different types of CNS nanofillers, underlying the key role played by the nanoscale shape and distribution of the components in driving the macroscopic behavior of the composite material. Surface properties are probed through advanced atomic force microscopy techniques, on both flat substrates (films) and confined systems (nanofibers). All these composites proved to be biocompatible and to support as scaffolds the proliferation of human neuronal precursor cell line SH-SY5Y, opening the route to a future comparative analysis on their ability to boost neuronal differentiation.

Synthesis, Properties, and Applications of Functionalized Carbon Nanostructures

Synthesis, Properties, and Applications of Functionalized Carbon Nanostructures

ChemInform Abstract: Metal—Organic Hybrid Architectures Built from Functionalized Fullerenes and Metal Ions or Clusters

AbstractReview: 71 refs.

Boosting Perovskite Solar Cells Performance and Stability through Doping a Poly‐3(hexylthiophene) Hole Transporting Material with Organic Functionalized Carbon Nanostructures

Perovskite solar cells (PSCs) are demonstrating great potential to compete with second generation photovoltaics. Nevertheless, the key issue hindering PSCs full exploitation relies on their stability. Among the strategies devised to overcome this problem, the use of carbon nanostructures (CNSs) as hole transporting materials (HTMs) has given impressive results in terms of solar cells stability to moisture, air oxygen, and heat. Here, the use of a HTM based on a poly(3‐hexylthiophene) (P3HT) matrix doped with organic functionalized single walled carbon nanotubes (SWCNTs) and reduced graphene oxide in PSCs is proposed to achieve higher power conversion efficiencies (η = 11% and 7.3%, respectively) and prolonged shelf‐life stabilities (480 h) in comparison with a benchmark PSC fabricated with a bare P3HT HTM (η = 4.3% at 480 h). Further endurance test, i.e., up to 3240 h, has shown the failure of all the PSCs based on undoped P3HT, while, on the contrary, a η of ≈8.7% is still detected from devices containing 2 wt% SWCNT‐doped P3HT as HTM. The increase in photovoltaic performances and stabilities of the P3HT‐CNS‐based solar cell, with respect to the standard P3HT‐based one, is attributed to the improved interfacial contacts between the doped HTM and the adjacent layers.

Carbon Nanostructures: Interactions with Biological Systems

The interest on functionalized carbon nanostructures in the nanomedicine field is constantly increasing and many different approaches have been used to study the interactions and the effects of these nanomaterials on cells.In this contribution we will mainly focus our attention on the analysis of genome expression of a cell line, comparing the results obtain before and after the treatment with two compounds, and taking into account the in vitro results obtained previously using traditional cytotoxicity test.

Non-covalently functionalized carbon nanostructures for synthesizing carbon-based hybrid nanomaterials.

Carbon nanostructures (CNSs) such as carbon nanotubes, graphene sheets, and nanodiamonds provide an important type of substrate for constructing a variety of hybrid nanomaterials. However, their intrinsic chemistry-inert surfaces make it indispensable to pre-functionalize them prior to immobilizing additional components onto their surfaces. Currently developed strategies for functionalizing CNSs include covalent and non-covalent approaches. Conventional covalent treatments often damage the structure integrity of carbon surfaces and adversely affect their physical properties. In contrast, the non-covalent approach offers a non-destructive way to modify CNSs with desired functional surfaces, while reserving their intrinsic properties. Thus far, a number of surface modifiers including aromatic compounds, small-molecular surfactants, amphiphilic polymers, and biomacromolecules have been developed to non-covalently functionalize CNS surfaces. Mediated by these surface modifiers, various functional components such as organic species and inorganic nanoparticles were further decorated onto their surfaces, resulting in versatile carbon-based hybrid nanomaterials with broad applications in chemical engineering and biomedical areas. In this review, the recent advances in the generation of such hybrid nanostructures based on non-covalently functionalized CNSs will be reviewed.

(Invited) Functionalized Carbon Nanostructures for Materials Science Applications: Opportunities Enabled by Flow Chemistry

not Available.

Redox‐enzymes, cells and micro‐organisms acting on carbon nanostructures transformation: A mini‐review

Carbon nanotubes, graphene and fullerenes are actual nanomaterials with many applications in different industrial areas, with increasing potentialities in the field of nanomedicine. Recently, different proactive approaches on toxicology and safety management have become the focus of intense interest once the industrial production of these materials had a significant growth in the last years, even though their short- and long-term behaviors are not yet fully understood. The most important concerns involving these carbon-based nanomaterials are their stability and potential effects of their life cycles on animals, humans, and environment. In this context, this mini review discuss the biodegradability of these materials, particularly through redox-enzymes, micro-organisms and cells, to contribute toward the design of biocompatible and biodegradable functionalized carbon nanostructures, in order to use these materials safely and with minimum impact on the environment.

Functionalization of graphane with alkali and alkaline-earth metals: An insulator-to-metallic transition

In view of interest in functionalized carbon nanostructures due to their potential applications in nanotechnology and nanoelectronics, we have performed a systematic and thorough density functional theory (DFT) study on the interaction of the elements in the first two groups of the periodic table with graphane (hydrogenated graphene) sheet. GGA approximation as employed in DFT has been used to study in detail the binding configuration, bond length, charge transfer and band gap of each of these adatoms doped graphane (CH) systems. To have a better understanding of the adatoms-CH interaction, different doping concentrations varying from 3.125% to 50% have been considered. A certain trend in binding strength, bond length and charge transfer has been found in the case of both alkali metal and alkaline-earth metal adatoms. In the case of alkali-metal adatoms at the low doping concentration of 3.125%, semiconductor behavior was found, whereas at doping higher than this the compound showed metallic behavior. In contrast, alkaline-earth metal-doped CH exhibited metallic behavior at all the doping concentrations.

Preparation and Characterization of Composites that Contain Small Carbon Nano‐Onions and Conducting Polyaniline

Small multilayer fullerenes, also known as carbon nano-onions (CNOs; 5-6 nm in diameter, 6-8 shells), show higher reactivity than other larger carbon nanostructures. Here we report the first example of an in situ polymerization of aniline on phenyleneamine-terminated CNO surfaces. The green, protonated, conducting emeraldine polyaniline (PANI) was directly synthesized on the surface of the CNO. The functionalized and soluble CNO/PANI composites were characterized by TEM, SEM, DSC, Raman, and infrared spectroscopy. The electrochemical properties of the conducting CNO/PANI films were also investigated. In comparison with pristine CNOs, functionalized carbon nanostructures show dramatically improved solubility in protic solvents, thus enabling their easy processing for coatings, nanocomposites, and biomedical applications.

High-Throughput Fabrication of Functionalized Carbon Nanostructures for DNA Detection

not Available.