We investigated the electrochemical lithium-ion storage properties of 9,10-anthraquinone (AQ) and 9,10-phenanthrenequinone (PhQ) molecules encapsulated in inner hollow core single-walled carbon nanotubes (SWCNTs). The structural obtained systems were characterized by electron microscopy, synchrotron powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy Raman spectroscopy. found that almost all quinone SWCNTs can store Li-ions reversibly. Interestingly, undesired...

We demonstrated in the present investigation that, by analyzing small-angle powder XRD pattern, we successfully determined not only pore-to-pore distance but also pore diameter of mesoporous materials having a quasi two-dimensional hexagonal structure. It was found that values this method were good accordance with those derived from nitrogen gas adsorption measurement (Kruk–Jaroniec–Sayari method) for several kinds silicas and carbons. Furthermore, owing to advantage determination it is...

The electrochemical behavior of highly crystallized single-walled carbon nanotubes (SWCNTs), having a small diameter distribution, is investigated by cyclic voltammetry (CV), using triethylmethylammonium tetrafluoroborate in propylene carbonate as an electrolyte. Unlike the CV curves previously observed other researchers and referred to "butterfly" shape, curve present study shows large bulges on both sides rest potential, thereby resembling dumbbell. By comparison electronic density states...

In order to understand the reason why polyiodide ions encapsulated in single-walled carbon nanotubes (SWCNTs) drastically improve electric conductivity and water dispersibility of SWCNTs at low temperature, we performed situ Raman measurements three kinds having different mean tube diameters under temperature down −100 °C. It was found that, for all samples, peak intensities increase G-band position shifts toward higher-wavenumber side with decreasing temperature. means that charge-transfer...

We demonstrate that iodine-doping into single-walled carbon nanotubes (SWCNTs) can be effectively done using an electrochemical method. It is shown by in situ Raman measurements the level easily and finely controlled because de-doping also possible changing polarity. In synchrotron XRD reveal iodine molecules are mainly inserted hollow core of SWCNTs. The dispersion state iodine-doped SWCNTs water as a function temperature investigated. homogeneously dispersed at low (ca. <15 °C).

We have performed Li and Na ion charge–discharge experiments of 9,10-phenanthrene quinone (PhQ) molecules encapsulated in single-walled carbon nanotubes (SWCNTs) with mean tube diameters 1.5 2.5 nm at room temperature also low temperatures. The reversible capacity PhQ the larger diameter SWCNTs, measured a 0 °C, remained as high that (RT), while smaller SWCNTs °C was about half RT. dependence should be attributed to difference interactions between host which revealed by Raman peak profile...

We prepared iodine molecules encapsulated in single-walled carbon nanotubes (I@SWCNTs) by electro-oxidation of iodide ions with empty SWCNT electrode. Li-ion battery electrode properties I@SWCNTs were investigated. It was found that the I@SWCNT sample can catch and release Li reversibly. performed Raman measurements to reveal storage mechanism I@SWCNT. is plausible chemical reactions I2 from/into LiI SWCNTs occur during charging/discharging also CsI@SWCNT verify alkali metal be extracted...

We investigated the physical and chemical stabilities of sulfur phosphorus molecules encapsulated in a mesoporous carbon (MPC) two kinds single-walled nanotubes (SWCNTs) having different cylindrical pore diameters. The sublimation temperatures MPC SWCNTs were measured by thermo-gravimetric measurements. It was found that temperature mean tube diameter 1.5 nm is much higher than any other larger pores. also capacity fading lithium-sulfur battery can be diminished encapsulation SWCNTs....

Structurally designed graphene-layers were synthesized by fusing two kinds of poly-aromatic hydro carbons: coronene and pentacene.

Abstract We describe the synthesis and visible-light CO 2 photoreduction catalytic properties of a three-component composite consisting AgI, AgIO 3 , single-walled carbon nanotubes (SWCNTs). The catalyst is synthesized by immersing SWCNTs encapsulating iodine molecules in AgNO aqueous solution, during which neutral (I ) encapsulated transform disproportionately to I 5+ (AgIO − (AgI), as revealed from characterization Raman spectroscopy, X-ray diffraction, photoelectron spectroscopy. In...

In the present study, ion adsorption on outer and inner surfaces of single-walled carbon nanotubes (SWCNTs) in different aqueous organic electrolytes was analysed. It found that fundamental properties tube size electronic structure, particularly transition between van Hove singularities (the band gap), reflected by shape cyclic voltammogram increase number charge carriers upon doping, apparently provided additional energy for inside open-end SWCNTs. addition, when voltammograms recorded at...

Visible photoluminescence properties of mesoporous nanocomposites carbon and silicon dioxides prepared using the triconstituent co-assembly method is reported. Intense white-light emission from was observed at room temperature, under 370-nm light irradiation after proper desorption by air-oxidation. We that shapes luminescence spectra, especially in green-yellow region, were highly dependent on oxidation condition samples.

We investigated the changes in charge carrier density responsible for dumbbell-like cyclic voltammogram of single-walled carbon nanotubes (SWCNTs) used as electric double layer capacitor electrodes. utilized situ Raman spectroscopy SWCNTs potential range where dumbbell is observed and charging would be dominant mechanism. The study revealed that, unexpectedly, spectroscopic coinciding with steps on occur more sharply metallic tubes, seen from (1) sudden enhancement intensity BWF...

To prepare nanosized graphene-like molecules of a defined structure (defined-width graphene nanoribbons or nanofragments) by simple bottom-up method, thermal polymerization reactions pentacenes were investigated. By optimizing heat treatment temperature and initial precursor weight, long-length fused pentacene successfully obtained at least up to octamer (n = 8). Here, the degree was much larger than that previously known polymerized systems 2, 3). The structural physical properties...

The effects of hydrolysis and polycondensation reactions for synthesizing light-emitting mesoporous carbon–silica (MPCS) nanocomposite on the structure, chemical bonding state, luminescence properties MPCS were investigated by controlling concentration (0.02 to 5 M) HCl, which was used as a catalyst polycondensation. progress provides nanometer-order pore/wall structure results in strong property. obtained using HCl at concentrations 0.2 M higher, but it became disordered with increasing (2...

We investigated the effect of diameter size single-walled carbon nanotubes (SWCNTs), on their high-temperature energy storage behavior in an electric double layer capacitor (EDLC) using ionic liquid triethyl(2-methoxyethyl) phosphonium bis(trifluoromethylsulfonyl)imide (P222(2O1)-TFSI). used four SWCNT samples with sizes ranging from 0.8 to 5 nm, and evaluated electrochemical charge through galvanostatic charge/discharge impedance spectroscopy (EIS). found that for SWCNTs small average 1...