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

摘要

Nanostructured TiO2/CNT (carbon nanotube) hybrids have been lately the focus of extensive research for their application in electroactive devices. A variety of structural combinations of TiO2 and CNT has been reported, but most of them employ TiO2 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 TiO2 nanotubes. The Co-TiO2 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 degrees C and 850 degrees 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 degrees C exhibited well-formed Co-TiO2/CNT arrays; it further showed superior photocurrent performance. The results indicate that TiO2/CNT nanoarchitectures are promising candidates for application as photoactive materials.