Structural, electronic, and electrical behaviour of MWCNTs: TiO2 (: SiO2) nanocomposites

We have functionalized multiwall carbon nanotubes (MWCNTs) with the composition of SiO2 and TiO2 (MWCNTs:TiO2:SiO2) at different Ti:Si stoichiometric ratios (Ti:Si approximate to 6:6 at% and approximate to 10:10 at%) using the hydrothermal process. The micro-structural, electronic and electrical properties of the unfunctionalized and functionalized MWCNTs were studied. Changes in surface morphology, degree of hybridization, crystallite structure and bonding structure due to functionalization were studied using field-emission scanning electron microscopy, Raman spectroscopy, x-ray diffraction, x-ray photoemission spectroscopy (XPS) and x-ray absorption near edge structure (XANES) spectroscopy techniques. Memristive and charge storage properties for MWCNTs: TiO2:SiO2 nanocomposites (NCs) are more pronounced on NCs functionalised with high stoichiometric ratio (Ti:Si approximate to 10:10) due to the contribution of Ti3+ and Si 2p core states as indicated by XPS and XANES results. The tunability of electrical conductivity is shown by an increase in the measured current and semiconducting I-V behaviour of the material as a result of high content of Ti-charge transfer. These observed changes in the electrical behaviour and electronic/bonding structure of the NCs indicate that the material could be useful for electrical/electronic applications and photocatalytic activity.