bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Soluble, Sometimes Liquid, Electron-Donating Phenothiazines for Batteries with Non-Aqueous Electrolytes
Authors: Odom Susan A , Casselman Matthew D , Kaur Aman Preet , Elliott Corrine F , Chapman Steven , Zhang Peter , Risko Chad 
Published: February 2020

Phenothiazines have seen widespread use as stable electron-donating organic compounds with generally stable oxidized states, making them an amenable core for functionalization toward electrochemical energy storage applications. With phenothiazine itself as a starting material, functionalization of the 3, 7, and 10 positions is facile, providing options to modify redox potentials and improve stability in both the neutral and singly oxidized (radical cation) states. In one to three steps, we can create highly soluble, stable derivatives that are suitable for applications requiring the donation of one or two electrons. We have observed thousands of hours of overcharge protection in lithium-ion batteries and more recently have moved into testing these species as the electro-active materials for non-aqueous redox flow batteries. This presentation will focus on the synthesis and characterization of new derivatives, highlighting new results in which we found that a liquid phenothiazine that can be prepared in one step from commercially-available starting materials can serve as an electron donor and solvent, dissolving some lithium salts to concentrations of at least 1 M.
Incorporation of Pyridinium Axial Ligands for Fe Phthalocyanines Anchorage on Carbon Nanotubes Electrodes for Biomimetic Oxygen Reduction
Authors: Oyarzun Maria Paz , Silva Nataly , Silva Juan Francisco , Ramirez Sara , Zagal Jose H 
Published: February 2020

Metallo phthalocyanines confined on electrode surfaces such as graphite and carbon materials have been used extensively as active molecular catalysts for a variety of reactions1. When anchored on carbon nanotubes the activity of these catalysts increases by almost 2 orders of magnitude in part due to an increase in effective area. Recently, Cao et al. have shown that anchoring FePc to carbon nanutubes using an axial ligand produces very active materiales for the reduction of O2 in alkaline media, mimicking in this fashion the function of cytochrome c in the catalytic reduction of O2 in living systems. In this work we have used iron phthalocyanines (FePcs) for O2 reduction in basic medium incorporated single wall carbon nanotubes (SWCNTs) modified with pyridiniums axial ligands (py) obtained by reacting diazonium salts. The two phthalocyanines used correspond to the unsubstituted iron phthalocyanine FePc and perchlorinated iron phthalocyanine (16(Cl)FePc)).
Our results show that for ORR:
(i) As expected, carbon nanotubes produce a pronounced increase in electrode surface area, favoring the incorporation of more active sites of the molecular catalysts studied.
(ii) The incorporation of the axial ligand causes an increase in the rate of ORR, resulting in the onset for ORR to more positive values compared to the response of electrodes having FePcs without the axial ligand..
(iii) Of the studied phthalocyanines, 16(Cl)FePc exhibits the highest catalytic activity (Fig.1) due to the synergistic effect of Cl electron withdrawing substituents and the electron withdrawing pyridinium axial ligand.

Acknowledgment:
Fondecyt Nº
1140192 and postdoctoral proyect Nº 3150271.

1. Zagal, J. H., Griveau, S., Silva, J. F., Nyokong, T. & Bedioui, F. Metallophthalocyanine-based molecular materials as catalysts for electrochemical reactions. Coord. Chem. Rev.
254,2755–2791 (2010).
2. Cao, R. et al. Promotion of oxygen reduction by a bio-inspired tethered iron phthalocyanine carbon nanotube-based catalyst. Nat. Commun.
4, 2076 (2013).

Figure 1
(Invited) Carbon Nanotube/Polymer Hole Transporting Layers Bring Enhanced Performance to Perovskite, Quantum Dot and Organic Photovoltaic Devices
Authors: Nicholas Robin john , Habisreutinger Severin , Snaith Henry , Watt Andrew , Sharkey J. Joseph 
Published: February 2020

Novel materials for solar cells have been developing very rapidly, for example perovskite based solar cells have recently experienced an unprecedented increase in efficiency to values exceeding 20% within just two years. An important part of the performance of these cells are issues such as stability, cost and manufacturability. In this presentation we demonstrate that the hole transporting layer in such cells can be replaced with polymer-functionalized single-walled carbon nanotubes (SWNTs) embedded in an insulating polymer matrix. With such a composite structure a power conversion efficiency of up to 15.3% is achieved. This layer shows a much improved moisture resistance and at the same time has a thermal stability significantly superior to other hole-transporting materials employed in high-performance perovskite solar cells. This is likely to be a critical development for enhancing the long-term stability of high-efficiency perovskite solar cells.
In addition the same type of SWNT/polymer hole transporting layer can be employed in both conventional organic PhotoVoltaic devices and devices made using colloidal quantum dots, both of which show efficiencies close to 10%. This type of novel hole transporting layer made from carbon nanotube may well have a very extensive range of applications based on its combination of selective conduction and robust performances
Electrosynthesised Metal (Ni, Fe, Co) Oxide Films on Single-Walled Carbon Nanotube Platforms and Their Supercapacitance in Acidic and Neutral pH Media
Authors: Adekunle Abolanle Saheed , Ozoemena Kenneth I. , Ebenso Eno E 
Published: February 2020

The need for alternative energy sources has led to renewed research interests in electrochemical energy storage systems, especially supercapacitors [1]. Carbon materials such as carbon blacks, carbon fibres, cloths and nanotubes [2], have been used as electrode supports in supercapacitors. Carbon nanotubes (CNTs) have attracted attention due to their unique properties such as high surface area and high porosity that lead to high power densities of supercapacitors [2]. In the quest for an alternative sources, researchers have explored the charge storage properties of different metal oxide systems such as anhydrous Co-Ni oxides in alkaline medium, MnO2 in neutral and acidic conditions, NiO in an acidic conditions [3], Co3O4 in an alkaline medium [4], and Fe3O4 in neutral solution (Na2SO4) and in both neutral and alkaline media [5], as an inexpensive alternatives to RuO2. In addition to good supercapacitive behaviour, metal oxides also have the advantage that they can be readily made into thin films.
Although, supercapacitive properties of metal oxides on different substrates have been reported, this work represents the first time a comparative study of the supercapacitive properties of three metal (Ni, Fe, Co) oxide nanoparticles electrochemically deposited onto SWCNTs was carried out. In this work, Supercapacitive properties of single-walled carbon nanotubes/metal oxides nanocomposites (SWCNT-MO where M=Ni, Fe, Co) is described. The SWCNT-MO nanocomposites were confirmed with SEM, EDX and XPS techniques. Supercapacitive properties of the modified electrodes in H2SO4 and Na2SO4 electrolytes was investigated using cyclic voltammetry (CV), galvanostatic constant current charge-discharge (CD) and the electrochemical impedance spectroscopy (EIS) techniques. Electrodecorating acid-functionalised SWCNTs with metal (Ni, Fe, Co) oxide nanoparticles leads to significant enhancements on the supercapacitive properties of these materials in acidic and neutral media compared to many other literature reports. SWCNT-NiO nanocomposite modified electrodes gave better supercapacitive performance with a specific capacitance of 186 mFcm-2 (or 928 Fg-1). This value compared quite favourably and even higher than values hitherto reported in several literature.

References

1. M. Winter, R. J. Brodd, Chem. Rev. 2004, 104, 4245.
2. A. T. Chidembo, K. I. Ozoemena, B. O. Agboola, V. Gupta, G. G. Wildgoose, R. G. Compton, Energy Environ. Sci. 2010, 3, 228.
3. Q. Wang, Z. Wen, J. Li, Adv. Funct. Mater. 2006, 16, 2141.
4. L. Cao, M. Lu, H. L. Li, J. Electrochem. Soc. 2005, 152, A871.
5. S. Y. Wang, K. C. Ho, S. L. Kuo, N. L. Wu, J. Electrochem. Soc. 2006, 153, A75.
Preparations of Turpentine Based Carbon Nanospheres As Anode Materials for Lithium Ion Batteries
Authors: Arie Arenst Andreas , Devina Konstantia Inez , Halim Martin , Lee Joong-Kee 
Published: February 2020

Nanocarbon such as carbon nanotubes (CNTs) and carbon nanospheres (CNSs) have excellent electrical properties so that they can be used to substitute graphite as anode material for lithium-ion battery. The use of nanocarbon as anode material provides a short path for the ion and electron movement in electrodes. Therefore, the energy density of the battery can be improved. In this research, the production of CNT and CNS was carried out through spray nebulization at 650, 700, and 750oC with 15, 30, and 45 min reaction time in the presence of ferrocene as catalyst with the concentration of 0.015; 0.02; 0.025 g/ml of hydrocarbon. Turpentine oil, an environmentally friendly precursor, was used as carbon source. The materials obtained was physically characterized by SEM, TEM, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Meanwhile, the electrochemical properties will be analized by plotting charge-discharge capacity vs cycle number and electrochemical impedance spectroscopy.
Photoluminescent Carbon Nanotubes Interrogate the Permeability of Multicellular Tumor Spheroids
Authors: Shamay Yosef , Jena Prakrit Vaibhav , Shah Janki , Roxbury Daniel , Paknejad Navid , Heller Daniel A 
Published: February 2020

The near-infrared photoluminescence from non-covalently dispersed single-walled carbon nanotubes (SWCNT) is optimally suited to probe distinct classes of biological environments. With aspect ratios of >100:1, nanotubes present an opportunity to observe atypical interactions between linear filamentous particles and three-dimensional biological environments. A pressing concern in therapeutic biomedicine is the inability of drug-carrying nanoparticles that function well in two dimensional cell cultures, to show efficacy in vivo. The inability of spherical nanoparticles to penetrate dense three-dimensional structures in a well defined point of failure. By exploiting the ability to image single carbon nanotubes via widefield fluorescence microscopy, we quantified the relative permeability of multi cellular tumor spheroids to a linear nanoparticle1. The results indicate the ability of nanoparticles to penetrate tumor spheroids depends strongly on the nanoparticle shape. Additionally, this platform portends a new approach to characterize the permeability of living multicellular environments.
References:

Photoluminescent carbon nanotubes interrogate the permeability of multicellular tumor spheroids, Yosef Shamay*, Prakit V. Jena*, et al, Carbon 97 (2016) 99-109
Carbon Nanotubes for Theranostics
Authors: Gajewska Agnieszka , Gonzalez Dominguez Jose Miguel , DaRos Tatiana 
Published: February 2020

The current technological development and application of Carbon Nanotubes (CNTs) unfailingly require the use of chemical tools. Pristine CNTs often need to be chemically processed or functionalized in order to exhibit the most suitable features and to optimize their handling in specific applications. Chemical functionalization stands therefore as a universal means to overcome CNTs insolubility in water, by rendering their surface hydrophilic, a necessary step towards promising biomedical outcomes.[1]

As a matter of fact, water-dispersible CNTs may not trigger immunitary responses, and also may present high cell uptake along with very low cytotoxicity as compared to their not functionalized counterparts,[2]stressing out the crucial role of the affinity and stability of CNTs in aqueous media.
Our recent efforts in the functionalization of carbon nanotubes are focused on the condition optimization to achieve a fast and versatile derivatization by introduction of appendages apt to increase dispersibility of the starting materials in polar solvent. The so obtained derivatives may be used as theranostic platform.
[1] N. Saito, H. Haniu, Y. Usui, K. Aoki, K. Hara, S. Takanashi, M. Shimizu, N. Narita, M. Okamoto, S. Kobayashi, H. Nomura, H. Kato, N. Nishimura, S. Taruta, M. Endo, Chem. Rev.
2013, 11, 6040-6079.
[2] S. Chen, S. Hu, E. F. Smith, P. Ruenraroengsak, A. J. Thorley, R. Menzel, A. E. Goode, M. P. Ryan, T. D. Tetley, A. E. Porter, M. S. P. Shaffer, Biomaterials
2014, 35, 4729-4862.
Targeting Type-I Eicosacationic [70]Fullerene-(Light Harvesting Antenna) PDI Agents for Efficient Photokilling of Multiantibiotics-Resistant Bacteria
Authors: Wang Min , Huang Yingying , Hamblin Michael , Chiang Long 
Published: February 2020

We are particularly interested in mediating broad-spectrum killing of pathogenic Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria targets. Systematic evaluation was taken to evaluate a structure–function relationship of fullerene-(light harvesting antenna) conjugative diads and triads on the influence of their biological activity, aiming to achieve the optimized photodynamic inactivation (PDI) efficiency against multiantibiotics-resistant bacteria.
Accordingly, we found a rational design of effective fullerene-based nano-photosensitizers by chemical modification of the carbon cage with two cell-targeting moieties each with a well-defined high number of cationic charges that allowed us to demonstrate the feasibility of these compounds giving cytotoxicity toward both Gram-positive and Gram-negative species. We also uncovered the large enhancement of PDI efficiency in photokilling of infectious bacteria by replacing the C60 cage with a C70 leading to novel type-I eicosacationic [70]fullerenes as potential nano-PDI agents.
Synthesis of Red Fluorescent Graphene Quantum Dots for the Bioimaging Platform
Authors: Fan Louzhen 
Published: February 2020

Graphene quantum dots (GQDs) have attracted much recent attention due to their ultrafine dimensions, tunable surface functionalities and economical synthetic routes. The stable photoluminescence (PL) and low toxicity make them outstanding as an alternative to organic dyes and inorganic quantum dots (QDs) in biological applications.1 On the other hand, due to the auto-fluorescence and light scattering background of biological specimens in the short-wavelength region, fluorescent materials of choice are expected to emit in the long-wavelength region in order to provide a deeper light penetration into the specimens, resulting in a higher imaging contrast. To date, most of the reported GQDs emit the blue to green fluorescence, which usually exhibits excitation wavelength dependence2. Herein, we report the facile electrochemical exfoliation of graphite in K2S2O8 solution for the synthesis of uniform small-sized red fluorescent GQDs (RF-GQDs) without any chemical modification, which has been used for cellular imaging.2

Acknowledgement: This work is supported by NSFC (21073018), the Major Research Plan of NSFC (21233003), the Fundamental Research Funds for the Central Universities.
Reference:

(a) S. N. Baker, G. A.Baker, Angew
.
Chem
.
Int
.
Ed
.
2010,
49, 6726-6744; (b) J. Shen, Y. Zhu, C. Chen, X. Yang, C. Li, Chem
.
Commun
.
2011,
47, 2580; (c) K. Habiba, V. I. Makarov, J. Avalos, M. J. F. Guinel, B. R. Weiner, G. Morell, Carbon 2013,
64, 341.

(a) Z. Fan, Y. Li, X. Li, L. Fan, S. Zhou, D. Fang, S. Yang, Carbon 2014, 70, 149; (b) M. Zhang, L. Bai, W. Shang, W. Xie, H. Ma, D. Fang, H. Sun, L. Fan, L.; Han, M.; Liu, C.; Yang, S., J
.
Mate
r.
Chem
.

2012, 22, 7461.
(Invited) Revisited Roles of Bimetallic Catalysts for Controlled CVD Growth of Single-Walled Carbon Nanotubes
Authors: Maruyama Shigeo , Xiang Rong , An Hua , Qian Yang , Cui Kehang , Kumamoto Akihito , Inoue Taiki , Chiashi Shohei , Ikuhara Yuichi 
Published: February 2020

Bimetallic catalysts such as Co-Mo have been used for efficient growth of vertically aligned single-walled carbon nanotube (SWNTs) for a decade [1]. Recently, different kinds of bimetallic catalyst such as Co-W [2] or Co-Cu [3] are employed for structure controlled growth of SWNTs. Different roles of bimetallic catalysts are revisited by newly proposed in-plane transmission electron microscopy (TEM) technique, which enables a direct TEM characterization of catalysts and CVD grown nanotubes on SiO2 TEM grid. Sputtered and dip-coated cobalt-based catalysts, i.e., Co, Co-Mo, Co-Cu, Co-W are used in alcohol catalytic CVD (ACCVD).
We found the Co oxide catalysts can efficiently grow narrower diameter and smaller average diameter SWNTs compared with pre-reduced Co catalysts. The in-plane TEM and X-ray photoelectron spectroscopy (XPS) reveal that Co catalysts are transformed to Co3O4 after reduction-calcination process and then decompose to CoO before growth at a typical growth temperature (800 ºC) in Ar atmosphere. We conclude that an in-situ reduction process occurred on low-mobility CoO after the introduction of ethanol is essential to activate small metallic Co catalysts. The in-plane TEM studies confirmed that Co-Mo bimetallic catalysts have the same mechanism as oxidized Co system, i.e. low mobility oxides and reduced metal, consistent with our previous report [1].
By using Co-Cu catalysts, we can synthesize vertically aligned SWNTs with subnanometer diameters on quartz (and SiO2/Si) substrates [3]. Scanning transmission electron microscopic energy-dispersive X-ray spectroscopy (EDS-STEM) and high angle annular dark field (HAADF-STEM) imaging of the Co/Cu bimetallic catalyst system showed that Co catalysts were captured and anchored by adjacent Cu nanoparticles, and thus were prevented from coalescing into larger size, which contributed to the small diameter of SWNTs.
High-melting point W6Co7 alloy is reported to grow a single chirality, (12,6) with over 90 % abundance through high-temperature (1030 ºC) reduction and growth [2]. Here, we show that a sputtered Co-W catalyst can selectively grow (12,6) SWNTs by CVD at lower temperatures. Statistical Raman mapping analysis and optical absorption spectrum of the as-grown SWNTs reveal that the abundance of (12,6) is over 50%. The morphology and structure of catalyst is investigated by the in-plane TEM, which discloses the complicated structure changes before and after growth.
References:
[1] M. Hu, Y. Murakami, M. Ogura, S. Maruyama, T. Okubo, J. Catalysis, 225 (2004) 230.
[2] F. Yang et al., Nature 510 (2014) 522.
[3] K. Cui, A. Kumamoto, R. Xiang, H. An, B. Wang, T. Inoue, S. Chiashi, Y. Ikuhara, S. Maruyama, Nanoscale, (2015) [DOI: 10.1039/C5NR06007A].
Raman Spectroscopic Evidence of the Selective Extraction of Metallic SWNTs By Polymethyl(1-undecylic acidyl)Silane
Authors: Gao Jinling , Huang Yao , Lian Yongfu 
Published: February 2020

Water soluble polymethyl(1-undecylic acidyl)silane was synthesized by the hydrosilylation of 10-undecylenic acid with polymethylsilane catalyzed by 2,20-azobisisbutyronitrile. The arc-discharged SWNTs were ultrasonically dispersed in an aqueous solution of polymethyl(1-undecylic acidyl)silane and then subjected to ultracentrifugation. Raman spectroscopic characterization confirmed that the supernatant is enriched in the metallic SWNTs, especially those with chiral indexes of (14,2), (15,0), (13,1), (12,3) and (19,1) metallic SWNTs. In this work, the SWNTs of larger diameters and smaller chiral angles than those reported previously were selectively extracted. Moreover, FT-IR spectroscopy and Raman scattering evidence the charge transfer between polymethyl(1-undecylic acidyl)silane and SWNTs. It is assumed that polymethyl(1-undecylic acidyl) silane could wrap chiral-index-selectively onto SWNTs through a fairly weak CH–p interaction, and that the stiffness and length of main chains and side chains as well as the charge state of the polymethylsilane derivative play vital roles in the selective extraction of metallic SWNTs.
(Invited) Porphyrin/Carbon Nanotube Supramolecular Self-Assembly : A Thermodynamical Approach
Authors: Delport Géraud , Vialla Fabien , Campidelli Stephane , Voisin Christophe , Lauret Jean-Sébastien 
Published: February 2020

Non covalent interactions through pi-stacking between carbon aromatic cores appear as an essential building block to engender the structural stability and electronic coupling of organic and biologic supramolecular assemblies (DNA, proteins, photosynthetic reaction center...). Interestingly pi-stacking functionalization has emerged as a rich and powerful way to synthesize hybrid compounds made from carbon nanotubes with organic molecules adsorbed on their sidewall. This scheme opens avenues for various applications including photo-voltaics, photo-detection, bio-sensing or imaging. In this context, we recently demonstrated that the decoration of nanotubes with dye molecules (porphyrins) brings remarkable properties including an efficient and ultrafast photo-induced energy transfer as well as good stability [1-3].
In the present work, we unveil through a thermodynamics study an original diameter dependence of the interaction between nanotubes and porphyrin monomers, which favors the larger diameters. We extract parameters such as the reaction time constant and the Gibbs energy of the reaction, which can be described by the classical cooperative adsorption Hill model. Moreover, the evolution of the Gibbs energy as a function of the nanotube diameter is studied for 16 nanotube chiral species [4], and compared with DFT calculations [5].
Finally, we show how tiny changes in the molecules structure influence their self assembly around the nanotube.
References
[1] C. Roquelet, et al, ChemPhysChem 2010, 11, 1667
[2] G. Clave, G. Delport et al, Chem. Mat. 2013, 25, 2700
[3] C. Roquelet, et al, Appl. Phys. Lett. 2010, 97,141918
[4] F. Vialla, G. Delport et al, Nanoscale, accepted
[5] W. Orellana et al, J. Mater Sci 2015, 50, 898