Determination of the diameter-dependent onset potential for the oxygenation of SWCNTs

The evaluation of the diameter-dependent onset potential for the oxygenation of a SWCNT (single-walled carbon nanotube) is an important issue because its chemical and physical properties, such as chemical reactivity, electronic conductance, and optical characteristics, would be changed. We investigated the diameter-dependent onset potential for the oxygenation of SWCNTs in neutral aqueous solution by using in situ Raman spectroelectrochemical measurements, which was explained quantitatively in terms of the strain energy per carbon atom. These results will be useful for the fabrication of materials in which CNTs are used as a platform for applications such as fuel cells, capacitors, and Li-ion batteries.