Probing the chemical interaction between different carbon allotropes oxides and titanium dioxide nanoparticles by Raman spectroscopy

Nanocomposites of TiO2 and carbon allotropes oxides (single and mull-walled nanotubes and graphene) have been prepared and characterized via scanning electron microscopy, thermogravimetric analysis and resonance Raman spectroscopy. The chemical interaction between TiO2 and the different forms of carbon was investigated and different levels of interaction was observed. More specifically, a selective electronic interaction process between TiO2 and semiconducting SWNTs is revealed. The displacement of the tangential G-band mode to a lower frequency in titania-SWNTs composite, which specifically occurs for semiconducting tubes (and not for metallic ones) indicated the addition of electrons to the SWNT pi band.