Nanotubes electrochemically synthesized

Kouzoudis D, Grimes CA (2006) Electrochemically synthesized CdS nanoparticle-modified Ti02 nanotube-array photoelectrodes Preparation, characterization, and... 

It occurs catalytically on the surface of Fe nanoparticles grown from Fe(CO)5. Also, the conventional synthesis of nanotubes by catalytic CVD from acetylene or methane can be formally considered as redox reaction. Nevertheless, the electrochemical model of carbonization (Sections 4.1.1 and 4.1.2) is hardly applicable for CVD and HiPco, since the nanotubes grow on the catalyst particle by apposition from the gas phase, and not from the barrier film (Figure 4.1). The yield and quality of electrochemically made nanotubes are usually not competitive to those of catalytic processes in carbon arc, laser ablation, CVD and HiPco. However, this methodology demonstrated that nanotubes (and also fullerenes and onions (Section 4.3)) can be prepared by soft chemistry" at room or sub-room temperatures [4,5,101]. Secondly, some electrochemical syntheses of nanotubes do not require a catalyst [4,5,95-98,100,101]. This might be attractive if high-purity, metal-free tubes are required. 

PPy nanotubes and nanowires can be also electrochemically synthesized through nanoporous AAO template in ionic liquids... 

Similar to PANI, the carbon-related materials, activated carbon, carbon nanotube, and GO, were also doped with PPy to fabricate PPy/carbon-related material composites for wastewater treatment. PPy/impregnated porous carbon was prepared by vapor infiltration polymerization technique to obtain a mesoporous structure [72], The as-prepared composite exhibited an improved adsorption ability to remove heavy metal ions, such as Hg(II), Pb(II), and Ag(I) due to amino groups of PPy. PPy/carbon nanotube composites can be prepared by grafting from technique either chemically or electrochemically. The chemical fabricated PPy/carbon nanotube composite can effectively remove heavy metals, anions and chemical oxygen demand from paper mill waste [73]. The electrochemical synthesized PPy/carbon nanotube provided a simple and highly effective method for ClO removal via electrically switched ion exchange technique (Figure 11.15) [74]. 

TouriUon, G. Pontonnier, L. Levy, J. P Langlais, V. Electrochemically synthesized Co and Fe nanowires and nanotubes. Electrochem. Solid State Lett. 2000, 3, 20-23. 

The synthesis of Pt metal nanowires and nanotubes electrochemically deposited through nanoporous membranes was reported by Ichikawa (2000). Palladium deposits with high specific surface areas, up to 50 m g", have been synthesized by Tsirlina et al. (2002) from palladium chloride solutions with additions of polyethylene glycol and polyvinyl pyrrolidone. Details of the globular structine of the deposits depend on the polymer additives. A comparison with electrochemically determined true surface areas demonstrates the coalescence of nanoparticles. Wang et al. (2003) electrochemically synthesized thin films composed of ordered arrays of palladium nanowires using silica mesoporous channels. Mesoporous channels were deposited on a conductive glass substrate. In this method, nanowires with face-centered cubic crystal structure are continuously deposited from the conductive substrate upward until the mesoporous channels are filled. 

In addition to spherical particle nanocomposites, the preparation of nanotubes and nanowires composites with both magnetic and electrical properties is of great interest due to the enhancement of the conductivity. In general, the room temperature conductivity increases when the diameter decreases [79]. Conducting polymer nanotubes can be chemically or electrochemically synthesized by hard and soft template or template-free method in the presence of magnetic nanoparticles [8, 23, 27]. 

The double layers of vanadium oxide found in the xerogel have been described in a number of other vanadium oxides by Galy ° and Oka ° they also form the double sheets described above for VeOis. These oxides, in which the vanadium is found in distorted VOe octahedra, show particularly attractive electrochemical capacities " exceeding 200 mAh/g in some cases, as shown in Figure 9. However, at the present time their rate capability appears somewhat limited. More recently vanadium oxide nanotubes have been synthesized, first by Spahr et these compounds also contain double sheets of vanadium oxide and again have interesting but complex... 

Owens and Iqbal [146] succeeded in an electrochemical hydrogenation of open-ended SWCNTs synthesized by CVD. Sheets of SWCNT bucky paper were used as the negative electrode in an electrochemical cell containing aqueous KOH solution as electrolyte. The authors claimed to have incorporated up to 6 wt. % of hydrogen into the tubes, determined by laser Raman IR spectroscopy and hydrogen release by thermolysis at 135 °C under TGA conditions [146], However, the stability of exohydrogenated carbon nanotubes and the low temperature of hydrogen release at 135 °C [146] is contradictory with the 400-500 °C reported elsewhere [79a, 145],... 

Ahmad S, Singh S (2008) Electrochromic device based on carbon nanotubes functionalized poly(methyl pyrrole) synthesized in hydrophobic ionic liquid medium. Electrochem Commun 10 895-898... 

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