Study of Band Gap of Carbon Nanotube-Titanium Dioxide Heterostructures

The authors present a photoluminescence and UV (ultraviolet)-optical absorbance study on single walled carbon nanotubes CNTs (carbon nanotubes) and TiO2 mixtures. The authors observed variation of 0.6 eV in optical gap for micrometric anatase and 0.1 eV for nanometric rutile or anatase at a concentration of CNTs of about 1.5 weight %. The large difference in  is attributed to differences in dimensions of dioxide grains and in morphology of CNTs/TiO2 composites. Photoluminescence emission is drastically reduced and absorption in the UV range is increased at low CNT concentration for both anatase and rutile phases.