Plasmon resonance is expected to occur in metallic and doped semiconducting carbon nanotubes in the terahertz frequency range, but its convincing identification has so far been elusive. The origin of the terahertz conductivity peak commonly observed for carbon nanotube ensembles remains controversial. Here we present results of optical, terahertz, and direct current (DC) transport measurements ...

We present first-principles density-functional calculations for the structural, electronic, and magnetic properties of substitutional 3d transition metal (TM) impurities in two-dimensional black and blue phosphorenes. We find that the magnetic properties of such substitutional impurities can be understood in terms of a simple model based on the Hund's rule. The TM-doped black phosphorenes with ...

The location and nature of the doped elements strongly affect the structural, electronic and optical properties of TiO₂. To tailor the band structure and modify the photoelectrochemical properties of TiO₂, a pair of dopants is selected. Fe and N atoms are inserted in the TiO₂ network at substitutional and interstitial sites with different relative distances. The main objective behind the differ...

in this paper, we propose and evaluate a novel design of a lightly doped drain and source carbon nanotube field effect transistor (ldds-cntfet) with a negative differential resistance (ndr) characteristic, called negative differential resistance ldds-cntfet (ndr-ldds-cntfet). the device was simulated by using a non equilibrium green’s function method. to achieve this phenomenon, we have created...

the aim of this research is studying the effects of ge-doped on co adsorption on the outer and inner surfaces of (6, 0) zigzag model of boron nitride nanotube (bnnts) by using dft theory. for this purpose, eight models of co adsorption on the surfaces of bnnts are considered. at first step, all structures were optimized at b3lyp and 6-31g (d) standard base set and then the electronic structure,...

Regularly spaced TiO2 nanotubes were prepared by anodizing a titanium substrate in triethylene glycol electrolyte at elevated temperature. In comparison to conventional TiO2 nanotubes, spaced nanotubes possess an adjustable spacing between the individual nanotubes; this allows for controlled buildup of a hierarchical nanoparticle-on-nanotube structure. Here, we use this principle for layer-by-l...

Analogous to multiwalled carbon nanotubes, nitrogen-doped carbon nanotube cups (NCNCs) have been synthesized with defined volumetric parameters (diameter and segment lengths) by controlling the catalyst particle size and the concentration of nitrogen precursor utilized in the chemical vapor deposition (CVD) reaction, allowing for tailored interior cavity space of cross-linked NCNCs, i.e. nanoca...

We have examined the time-dependent effect of the titanium oxide photocatalysis on N-methyl-2-pyrrolidone individually dispersed single walled carbon nanotube (SWNT) suspensions. From optical spectroscopic studies, we found a selective decoration of the semiconducting tubes. Such selectivity is attributed to the preferential attack of the photogenerated active species on the hole-doped semicond...

An activated carbon nanofiber (CNF) is prepared with incorporated Fe-N-doped graphene nanoplatelets (Fe@NGnPs), via a novel and simple synthesis approach. The activated CNF-Fe@NGnP catalysts exhibit substantially improved activity for the oxygen reduction reaction compared to those of commercial carbon blacks and Pt/carbon catalysts.

We report a high performance oxygen reduction reaction (ORR) catalyst based on vertically aligned, nitrogen-doped carbon nanotube (VA-NCNT) arrays. Characterization in conditions analogous to the operation of a polymer electrolyte membrane fuel cell show ORR taking place on the catalyst at a favorable reduction potential with a superior current density and greater rate constant.