In situ Raman spectroelectrochemistry of SWCNT bundles: Development of the tangential mode during electrochemical charging in different electrolyte solutions

The Raman spectra of metallic tubes in SWCNTs (Single wall carbon nanotubes) bundles during electrochemical doping have been investigated using three different electrolyte solutions: LiClO 4 /CH 3 CN, LiClO 4 /propylenecarbonate/poly(methyl methacrylate) and LiClO 4 /polyethyleneimine. Precise control of the electrochemical charging enabled us to follow the detailed development of the tangential displacement (TG) mode of SWCNT bundles in dependence on the electrode potential. The response of the TG mode to electrode potential was dependent on electrolyte used as a consequence of different doping efficiency. We demonstrate that the liquid electrolyte solution (LiClO 4 /CH 3 CN) has superior doping efficiency to those of both the tested polymer electrolytes.