Redox-active nickel in carbon nanotubes and its direct determination

The presence of residual metal-catalyst impurities in carbon nanotubes is responsible for their toxicity. It is important to differentiate between the total amount of impurities and the redox-active (bioavailable) amount of such impurities because only the bioavailable impurities exhibit toxic effec...

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Bibliographic Details
Main Authors: Ambrosi, Adriano, Pumera, Martin
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2013
Online Access:https://hdl.handle.net/10356/99147
http://hdl.handle.net/10220/12937
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Institution: Nanyang Technological University
Language: English
Description
Summary:The presence of residual metal-catalyst impurities in carbon nanotubes is responsible for their toxicity. It is important to differentiate between the total amount of impurities and the redox-active (bioavailable) amount of such impurities because only the bioavailable impurities exhibit toxic effects. Herein, we report a simple and specific method for quantifying the amount of redox-active Ni present in various commercial samples of CNTs. It is based on the electrochemical oxidation of Ni(OH)2 that is formed in alkaline solutions when Ni impurities are opened to the surrounding environment. Metallic Ni impurities play an extremely active role in toxicological assays as well as in undesired catalytic processes, and thus a method to rapidly quantify the amount of redox-active Ni is of great importance.