SnO2 nanotubes are synthesized via an oxalate-assisted "redox etching and precipitating" route between MnOOH nanowires and Sn2+ ions. The addition of oxalate is found to be crucial to guide the formation of uniform SnO2 nanotubes. To further improve the conductivity and stability, the as-obtained SnO2 nanotubes are coated with a thin carbon layer. The resulting carbon-confined SnO2 nanotubes po...

Low-frequency dielectric responses of carbon nanotubes are important for their manipulation, separation, and electronic applications. Here we report the first experimental measurement of near-dc polarization of individual carbon nanotubes by using modified scanning force microscopy techniques. The transverse polarizability of carbon nanotubes is equivalent to solid cylindrical media with a diel...

choline oxidase (chox) was chosen as a model enzyme for evaluating the performance of cnts’ functional groups for development of enzyme electrodes. cnts were functionalized with carboxylic acid, amine or amide groups. carboxylic acid, amine and amide functionalized cnts were obtained by acid treatment, ethylenediamine or tetraethylenepentamine chemically modification and ammonia plasma treatmen...

the electrocatalytic oxidation of captopril (cap) was studied by modified carbon nanotubes paste electrode in the presence of isoproterenol (ispt) using cyclic voltammetry (cv), chronoamperometry and square wave voltammetry (swv). also, the values of catalytic rate constant (k), and electron transfer coefficient (α) for cap were calculated. the mechanism of ca electrochemical behavior at the mo...

the electrochemical oxidation and determination of tryptophan (trp) and glutathione (gsh) in the presence of catechol as a homogeneous redox in the aqueous medium were investigated at the surface of a carbon paste electrode modified with multi-walled carbon nanotube (mwcnt-cpe) using cyclic voltammetry (cv), double step potential chronoamperometry and differential pulse voltammetry (dpv) techni...

the effects of electronic properties of inner and outer surfaces of carbon nano tubes (cnts) on the deactivation of cobalt fischer-tropsch (ft) catalysts were studied. the comparative characterization of the fresh and used catalysts by tem, xrd, tpr, bet and h2 chemisorption showed that cobalt re-oxidation, cobalt-support interactions and sintering are the main sources of catalyst deactivation....

Nanoscale transistors employing an individual semiconducting carbon nanotube as the channel hold great potential for logic circuits with large integration densities that can be manufactured on glass or plastic substrates. Carbon nanotubes are usually produced as a mixture of semiconducting and metallic nanotubes. Since only semiconducting nanotubes yield transistors, the metallic nanotubes are ...

We present an improvement in the electrical properties of silica nanotubes by coating metal nanoparticles on their surfaces. The silica nanotubes are formed from bacterial flagella bio-templates having a tubular structure. Successive depositions of metal nanoparticles on the silica nanotubes are performed through easily functionalized silica surfaces. The results show uniform metal nanoparticle...

A room-temperature, open-air method is devised to selectively intercalate relatively low-molecular-weight polymers (approximately 10-100 kDa) from dilute, volatile solutions into open-end, as-grown, wettable carbon nanotubes with 50-100 nm diameters. The method relies on a novel self-sustained diffusion mechanism driving polymers from dilute volatile solutions into carbon nanotubes and concentr...

Aligned carbon nanotubes have great potential for advanced nanotube transistors and integrated circuits. In this article, we studied the carbon nanotube alignment mechanism using a chemical vapor deposition growth on a-plane sapphire substrates. We synthesized carbon nanotubes of different diameters by controlling the catalyst size and observed that nanotubes of smaller diameters had a higher d...