The adsorption of simple benzene derivatives composed of a benzene ring with NO2, CH3, or NH2 functional groups on a semiconducting single-wall carbon nanotube is studied using the density-functional theory within the local-density approximation. The effects of molecular relaxation in the adsorption process are obtained, as well as the adsorption energies and equilibrium distances for several m...

Carbon nanotubes are a new allotrope of carbon which emerged from the fullerene family [1]. Carbon nanotubes have been discovered by high resolution transmission electron microscopy (HRTEM) in 1991 by Iijima [2]. A single wall carbon nanotube is constituted of one atomic plane with a graphite-like arrangement of C atoms – called a graphene sheet – which is perfectly rolled into a cylinder (Fig....

Adsorption of hydrogen molecules on platinum-doped single-walled zigzag (8,0) boron nitride (BN) nanotube is investigated using the density-functional theory. The Pt atom tends to occupy the axial bridge site of the BN tube with the highest binding energy of -0.91 eV. Upon Pt doping, several occupied and unoccupied impurity states are induced, which reduces the band gap of the pristine BN nanot...

The synthesis of water-soluble nitrogen-doped carbon dots has received great attention, due to their wide applications in oxygen reduction reaction, cell imaging, sensors, and drug delivery. Herein, nitrogen-doped, carbon-rich, highly photoluminescent carbon dots have been synthesized for the first time from ammonium citrate under hydrothermal conditions. The obtained nitrogen-doped carbon dots...

We consider the effects of Coulomb interactions on single-wall carbon nanotubes using an on-site Hubbard interaction, u . For the ~N ,N! armchair tubes the low-energy theory is shown to be identical to a two-chain Hubbard model at half-filling, with an effective interaction uN5u/N . Umklapp scattering leads to gaps in the spectrum of charge and spin excitations which are exponentially small for...

Current carbon nanotube (CNT) synthesis methods include the production of ordered, free-standing vertically aligned arrays, the properties of which are partially governed by interactions between adjacent tubes. Using material parameters determined by atomistic methods, here we represent individual CNTs by a simple single degree of freedom (SDOF) “lollipop” model to investigate the formation, me...

An in situ composite synthesis technique has been developed by grafting polystyrene chains onto single-wall carbon nanotubes (SWNTs) via a single-step debundling/polymerization scheme. The method, based on established anionic polymerization techniques, eliminates the need for nanotube pretreatment prior to functionalization and allows attachment of polymer molecules to pristine tubes without al...

We report in situ measurements of four-probe dc resistance ~R! and thermopower ~S! of Csand K-doped single-wall carbon nanotube ~SWNT! mats as a function of a doping and temperature ~T!. With increasing dopant exposure, the mat resistance has been found to first decrease and then increase, exhibiting a minimum for optimal Cs doping. In contrast, for K doping, the mat resistance decreased monoto...

We demonstrate that nitrogen doped, multi-walled carbon nanotubes (CN(x)-MWNT) result in photo-ablative destruction of kidney cancer cells when excited by near infrared (NIR) irradiation. Further, we show that effective heat transduction and cellular cytotoxicity depends on nanotube length: effective NIR coupling occurs at nanotube lengths that exceed half the wavelength of the stimulating radi...