Novel nanoarchitectured cobalt-doped TiO2 and carbon nanotube arrays: Synthesis and photocurrent performance

Abstract Nanostructured TiO 2 /CNT (carbon nanotube) hybrids have been lately the focus of extensive research for their application in electroactive devices. A variety of structural combinations of TiO 2 and CNT has been reported, but most of them employ TiO 2 nanoparticles over the carbon nanotubes. One-dimensional nanomaterials, such as nanotubes, usually possess enhanced properties when compared to nanoparticles, like improved electron mobility. This work presents a novel synthesis process of nanoarchitectures of CNTs intimately connected to cobalt-doped TiO 2 nanotubes. The Co-TiO 2 nanotubes were obtained by anodization and employed as a substrate for CNT synthesis by chemical vapor deposition (CVD). CVD was performed in a range of temperatures between 650 °C and 850 °C. The synthesized nanostructures were characterized via X-ray diffraction, Raman spectroscopy, scanning, and transmission electron microscopy. The generated photocurrent density of the nanoarchitectures was measured by linear voltammetry. The sample synthesized at 750 °C exhibited well-formed Co-TiO 2 /CNT arrays; it further showed superior photocurrent performance. The results indicate that TiO 2 /CNT nanoarchitectures are promising candidates for application as photoactive materials.