Synthesis, characterization and electrical properties of visible-light-driven Pt-ZnO/CNT

This paper deals with synthesis of ZnO doped with different concentrations of platinum (Pt) and its deposition on the surface of multi-walled carbon nanotube (MWCNT). The synthesized nanocomposite material was characterized by standard analytical techniques like X-ray diffraction (XRD), UV-vis spectroscopy, scanning electron microscopy, transmission electron microscopy and energy-dispersive spectroscopy. The XRD analysis confirms two things; first, synthesized nanocomposite shows no impurity peaks indicating products being crystalline in nature, second, the phase structure of composite remains unchanged during doping of Pt into ZnO crystal. Results indicate that the incorporation of dopant into ZnO coated on the surface of MWCNT was found to shift the fundamental absorption edge towards the longer wavelength side. The impedance analysis was carried out to distinguish between the grain and grain boundary contributions to the system. The dielectric property was strongly affected by increasing the dopant concentration. The dielectric constant (epsilon) and dielectric loss (tan delta) factors decrease with the increase in frequency only upto a certain limit. The a.c. conductivity also increases with the increase in frequency.