The change of the state of an endohedral fullerene by encapsulation into SWCNT: a Raman spectroelectrochemical study of Dy3N@C80 peapods

Raman and in situ Raman spectroelectrochemical studies of Dy3N@C80@SWCNT peapods have been carried out for the first time. The formation of peapods by the encapsulation of gaseous Dy3N@C80 has been confirmed by HR-TEM microscopy and by the successful transformation of Dy3N@C80@SWCNT into double-walled carbon nanotubes. The Raman spectra of the endohedral fullerene cluster changed dramatically in the interior of the single-walled carbon nanotube (SWCNT). The electrochemical charging of the peapod indicates a slight reversible attenuation of the Raman intensities of fullerene features during anodic doping. The results support the assignment of Raman bands to the Dy3N@C80 moiety inside a SWCNT.