Conventional Multi-walled Carbon Nanotubes Research Articles

Boron-Filled Hybrid Carbon Nanotubes.

A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs.

Enzyme-less and low-potential sensing of glucose using a glassy carbon electrode modified with palladium nanoparticles deposited on graphene-wrapped carbon nanotubes

The article describes an amperometric sensor for enzyme-less detection of glucose based on homogeneously anchored Pd nanoparticles (Pd-NPs) on graphene - wrapped carbon nanotubes (Pd-GWCNTs) as sensing matrix. The unique features of GWCNTs (such as the highly protruded outer graphene layer and an inner tubular morphology) result in enhanced electrochemical performance compared to the use of conventional multi walled carbon nanotubes (MWCNTs). Glucose electro-oxidation occurs at a rather low working potential (+50 mV vs Ag/AgCl), and glucose can be continuously sensed in 0.1 M NaOH solution in concentrations of up to 19.5 mM. The sensor possesses good reproducibility, a fast response time, stable amperometric response and a lower detection limit. Due to its low working potential, it is not interfered by dopamine, uric acid, ascorbic acid, sucrose, fructose and lactose. We presume that these beneficial properties are a result of the synergetic advantages of using catalytic Pd NPs and graphene wrapped CNTs, both of which facilitate low-potential electrooxidation of glucose.

Self-catalytic synthesis, structure and properties of ultra-fine luminescent ZnOnanostructures for field emission applications

A facile method to produce high-quality ZnO nanostructures; either tetrapod (TP),nanotetraneedle (NTN) or multipod (MP) with a high degree of homogeneity foradvanced field emission (FE) applications is presented. Among these nanostructures,NTN has been successfully employed to demonstrate enhanced current densities(2.6 mA cm − 2), turn-onfield (1.5 V µm − 1) and field-enhancement factors (6930) over conventional multiwalled carbon nanotubes(MWCNTs), TP, MP and ZnO-spheroids. A comparative study of FE from various ZnOnanostructures, morphologies and site densities has lead to the conclusion that diameter ofthe tip is one of the vital parameters in enhancing the overall FE properties.