Vertically-aligned sandwich nanowires enhance the photoelectrochemical reduction of hydrogen peroxide: hierarchical formation on carbon nanotubes of cadmium sulfide quantum dots and Prussian blue nanocoatings.

We describe a vertically-aligned array of sandwiched nanowires comprising Prussian blue (PB) nanocoating-carbon nanotube (CNT) core-shell structures with CdS particles positioning at the core/shell interface, viz. PB/CdS/CNT. The PB/CdS/CNT electrode thus constructed are noticeable in synchronically harvesting photon-, ionic-, and chemical-energies, respectively, from visible light radiation, K(+) uptaking and releasing, and the reduction of H2O2.

Heterojunction nanowires having high activity and stability for the reduction of oxygen: formation by self-assembly of iron phthalocyanine with single walled carbon nanotubes (FePc/SWNTs).

A self-assembly approach to preparing iron phthalocyanine/single-walled carbon nanotube (FePc/SWNT) heterojunction nanowires as a new oxygen reduction reaction (ORR) electrocatalyst has been developed by virtue of water-adjusted dispersing in 1-cyclohexyl-pyrrolidone (CHP) of the two components. The FePc/SWNT nanowires have a higher Fermi level compared to pure FePc (d-band center, DFT=-0.69 eV versus -0.

Vertically-aligned Prussian blue/carbon nanotube nanocomposites on a carbon microfiber as a biosensing scaffold for ultrasensitively detecting glucose.

We describe our assembly and the analytical performance of a glucose biosensor consisting of an array of carbon nanotubes (CNTs) that perpendicularly fall on a 7-μm-diameter carbon fiber and are modified by a "dual" enzymatic system-viz. glucose oxidase (GOx) and Prussian blue (PB, an artificial peroxidase). We chose to use the PB-catalyzed reduction reaction of hydrogen peroxide, an end-product of the GOx-catalyzed oxidation of glucose, to "relay" electrons from GOx to the substrate electrode.

Enhanced electrocatalytic performance of processed, ultrathin, supported Pd-Pt core-shell nanowire catalysts for the oxygen reduction reaction.

We report on the synthesis, characterization, and electrochemical performance of novel, ultrathin Pt monolayer shell-Pd nanowire core catalysts. Initially, ultrathin Pd nanowires with diameters of 2.0 ± 0.

Platinum-monolayer shell on AuNi(0.5)Fe nanoparticle core electrocatalyst with high activity and stability for the oxygen reduction reaction.

We describe a simple method for preparing multimetallic nanoparticles by in situ decomposition of the corresponding Prussian blue analogue, which is adsorbed on carbon black. The example involves the AuNi(0.5)Fe core of the Pt(ML)/Au(1)Ni(0.

Nitrogen-doped carbon nanotube arrays with high electrocatalytic activity for oxygen reduction.

The large-scale practical application of fuel cells will be difficult to realize if the expensive platinum-based electrocatalysts for oxygen reduction reactions (ORRs) cannot be replaced by other efficient, low-cost, and stable electrodes. Here, we report that vertically aligned nitrogen-containing carbon nanotubes (VA-NCNTs) can act as a metal-free electrode with a much better electrocatalytic activity, long-term operation stability, and tolerance to crossover effect than platinum for oxygen reduction in alkaline fuel cells. In air-saturated 0.

Electrochemistry and electroanalytical applications of carbon nanotubes: a review.

This review addresses recent developments in electrochemistry and electroanalytical chemistry of carbon nanotubes (CNTs). CNTs have been proved to possess unique electronic, chemical and structural features that make them very attractive for electrochemical studies and electrochemical applications. For example, the structural and electronic properties of the CNTs endow them with distinct electrocatalytic activities and capabilities for facilitating direct electrochemistry of proteins and enzymes from other kinds of carbon materials.

Rational attachment of synthetic triptycene orthoquinone onto carbon nanotubes for electrocatalysis and sensitive detection of thiols.

This study demonstrates a novel electrochemical method for sensitive determination of biological thiols including homocysteine, cysteine, and glutathione based on rational functionalization of single-walled carbon nanotubes (SWNTs) with synthetic triptycene orthoquinone (TOQ). Unlike previous strategies used for the functionalization of the carbon nanotubes to fabricate new kind of electrochemically functional nanostructures, the method demonstrated here is essentially based on understanding of the redox properties inherent in the SWNTs themselves. It is demonstrated that the electrochemical oxidation of the thiols at the SWNT-modified electrode is redox-mediated by the quinone-like functional groups at the tube ends and that the low density of such functional groups leads to a follow-up oxidation of the thiols at a more positive potential at the electrode.

Continuous on-line monitoring of extracellular ascorbate depletion in the rat striatum induced by global ischemia with carbon nanotube-modified glassy carbon electrode integrated into a thin-layer radial flow cell.

This study describes a novel analytical system integrating in vivo microdialysis sampling with a radial thin-layer flow cell with a single-walled carbon nanotube (SWNT)-modified glassy carbon electrode as working electrode for continuous and on-line monitoring of ascorbate depletion in the rat striatum induced by global ischemia. The SWNTs, especially those after vacuum heat treatment at 500 degrees C, are found to be able to enhance the electron-transfer kinetics of ascorbate oxidation at a low potential (ca. -50 mV) and possess a strong ability against electrode fouling.

Layer-by-layer assembled carbon nanotubes for selective determination of dopamine in the presence of ascorbic acid.

Multilayer films of shortened multi-walled carbon nanotubes (MWNTs) are homogeneously and stably assembled on glassy carbon (GC) electrodes using layer-by-layer (LBL) method based on electrostatic interaction of positively charged poly(diallyldimethylammonium chloride) (PDDA) and negatively charged shortened MWNTs. The assembled MWNT multilayer films were studied with respect to the electrocatalytic activity toward ascorbic acid (AA) and dopamine (DA) and were further applied for selective determination of DA in the presence of AA. Scanning electron microscopy (SEM) used for characterization of MWNT films indicates that the assembled MWNTs are almost in a form of small bundles or single nanotubes on the electrodes.

Sol-gel-derived ceramic-carbon nanotube nanocomposite electrodes: tunable electrode dimension and potential electrochemical applications.

Nanocomposite electrodes made of sol-gel-derived ceramic-carbon nanotube are fabricated by doping mutliwalled carbon nanotubes (MWNTs) into a silicate gel matrix. The electrochemical behavior and potential electrochemical applications of the ceramic-carbon nanotube nanocomposite electrodes (CCNNEs) are also studied. The as-prepared CCNNEs exhibit a tunable dimension ranging from conventional electrode to nanoelectrode ensemble (NEE), depending on the amount of the MWNT dispersed in the silica sol and finally doped within the gel matrix.

Electrostatic layer-by-layer assembled carbon nanotube multilayer film and its electrocatalytic activity for O2 reduction.

Multilayer films of shortened multiwalled carbon nanotubes (MWNTs) are homogeneously and stably assembled on glassy carbon electrodes with the layer-by-layer (LBL) method, based on electrostatic interaction of positively charged poly(diallyldimethylammonium chloride) and negatively charged and shortened MWNTs. The film assembly and electrochemical property as well as the electrocatalytic activity toward O2 reduction of the MWNT multilayer film are studied. Scanning electron microscopy, the quartz crystal microbalance technique, ultraviolet-visible-near-infrared spectroscopy, and cyclic voltammetry are used for characterization of film assembly.

Novel electrochemical method for sensitive determination of homocysteine with carbon nanotube-based electrodes.

An electrochemical method has been successfully demonstrated for sensitive determination of homocysteine (HcySH) with carbon nanotube (CNT)-modified glassy carbon (GC) electrodes. Cyclic voltammetric results clearly show that carbon nanotubes, especially those pretreated with nitric acid, possess an excellent electrocatalytic activity toward the oxidation of HcySH at a low potential (0.0 V versus Ag/AgCl).