Oxygen carbon nanotubes

Metal-Free Catalysis by Oxygen-Containing Carbon Nanotubes... 

AlexeyevaN, Laaksonen T. 2006. Oxygen reduction on gold nanoparticle/multi-walled carbon nanotubes modified glassy carbon electrodes in acid solution. Electrochem Commun 8 1475-1480. 

Pulskamp, K., Diabate, S., and Krug, H.F. (2007) Carbon nanotubes show no sign of acute toxidty but induce intracellular reactive oxygen spedes in dependence on contaminants. Toxicology Letters, 168 (1), 58-74. 

Due to their moderate specific surface area, carbon nanotubes alone demonstrate small capacitance values. However, the presence of heteroatoms can be a source of pseudocapacitance effects. It has been already proven that oxygenated functional groups can significantly enhance the capacitance values through redox reactions [11]. Lately, it was discovered that nitrogen, which is present in carbon affects also the capacitance properties [12]. 

J. Qu, Y. Shen, X. Qu, and S. Dong, Preparation of hybrid thin film modified carbon nanotubes on glassy carbon electrode and its electrocatalysis for oxygen reduction. Chem. Commun. 1, 34—35... 

Collins, P. G., Bradley, K., Ishigami, M., and Zettl, A. 2000. Extreme oxygen sensitivity of electronic properties of carbon nanotubes. Science 287 1801-1804. 

Some of the currently used therapeutics, and pitfalls associated with them, have been outlined above. Carbon nanomaterials may be beneficial in oncology to deliver chemotherapeutic agents or begin cascades of damaging molecules like radical oxygen species. Although C60 fullerenes and carbon nanotubes are closely related, they have very different pathways as potential therapeutics in oncology. 

P. M. Ajayan, T. W. Ebbesen, Ichihashi, S. Ijima, K. Tanigaki, H. Hiura, Opening carbon nanotubes with oxygen and implications for filling, Nature, vol. 362, pp. 522-525,1993. 

Yang, W., et al., Carbon nanotubes decorated with PtnNanocubes by a noncovalent functionalization method and their role in oxygen reduction. Advanced Materials, 2008. 20(13) p. 2579-2587. 

Wang, Z., et al., The synthesis of ionic-liquid-functionalized multiwalled carbon nanotubes decorated with highly dispersedAu nanoparticles and their use in oxygen reduction by electrocatalysis. Carbon, 2008. 46(13) p. 1687-1692. 

Liang, Y., et al., Oxygen reduction electrocatalyst based on strongly coupled cobalt oxide nanocrystals and carbon nanotubes. Journal of the American Chemical Society, 2012.134(38) p. 15849-15857. 

Sheng, W., et al., Synthesis, activity and durability ofPt nanoparticles supported on multi-walled carbon nanotubes for oxygen reduction. Journal of The Electrochemical Society, 2011. 158(11) p. B1398-B1404. 

Carbon is unique among chemical elements since it exists in different forms and microtextures transforming it into a very attractive material that is widely used in a broad range of electrochemical applications. Carbon exists in various allotropic forms due to its valency, with the most well-known being carbon black, diamond, fullerenes, graphene and carbon nanotubes. This review is divided into four sections. In the first two sections the structure, electronic and electrochemical properties of carbon are presented along with their applications. The last two sections deal with the use of carbon in polymer electrolyte fuel cells (PEFCs) as catalyst support and oxygen reduction reaction (ORR) electrocatalyst. 

Xia, W. Wang, Y. Bergstrafier, R. Kundu, S. Muhler, M., Surface characterization of oxygen-functionalized multi-walled carbon nanotubes by high-resolution X-ray photoelectron spectroscopy and temperature-programmed desorption. Appt. Surface Science 2007,254 247-250. 

To summarize, one can say that the electrochemical performance of CNT electrodes is correlated to the DOS of the CNT electrode with energies close to the redox formal potential of the solution species. The electron transfer and adsorption reactivity of CNT electrodes is remarkably dependent on the density of edge sites/defects that are the more reactive sites for that process, increasing considerably the electron-transfer rate. Additionally, surface oxygen functionalities can exert a big influence on the electrode kinetics. However, not all redox systems respond in the same way to the surface characteristics or can have electrocatalytical activity. This is very dependent on their own redox mechanism. Moreover, the high surface area and the nanometer size are the key factors in the electrochemical performance of the carbon nanotubes. 

In other publications single-walled carbon nanotubes were shown to promote neoplasm formation in kidneys [22, 23], Contrary to [20], other authors found that carbon nanostructures were capable of inducing reactive oxygen species (oxygen radicals) that could damage cellular structures [24-26],... 

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