Synthesis and Characterization of TiO2 nanorod supported on stainless steel mesh prepared via sol-gel method.

Abstract

Semiconductor metal oxide such as TiO2 has received significant attention in the field of material science owing to its low cost, stability, environmental friendliness and excellent photocatalytic activity. However, fast electron-hole recombination rate, high band gap, post-separation and recovery of the used TiO2 photocatalysts from wastewater after treatment limited its full scale industrial applications. In the light of this background, the present study investigated the synthesis of TiO2 nanorods supported on stainless steel mesh using a sol-gel solution of Polyvinylpyrrolidone (PVP), ethanol and titanium tetrachloride (TiCl4). The influence of pyrolysis temperature on the particles size, morphologies, microstructures and surface areas on the prepared supported catalyst were investigated. The as-synthesised nanorods were characterized by High Resolution Scanning Electron Microscope (HRSEM), High Resolution Transmission Electron Microscope (HRTEM), Energy Diffraction Spectroscopy (EDS), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, and X-ray photoelectron spectroscopy (XPS) analysis. The HRSEM and HRTEM analysis confirmed the formation of densely grown, well defined and uniformly aligned nanorod covered the whole surface of stainless steel mesh. The XRD analysis demonstrated the formation of pure tetragonal anatase phase of TiO2 irrespective of pyrolysis temperature and no rutile or brookite phase were detected. The average crystalline size of TiO2 nanorod decreased from 45 nm to 28 nm as the temperature increases from 300°C to 400 °C at constant holding time of 2 hrs. The specific surface area of the supported as-synthesised TiO2 nanorods was in the order of prepared at 400 °C (81 m2/g) > 350 °C (77 m2/g) > 300 °C (62 m2/g). The XPS analysis revealed the Ti in the prepared TiO2 is in +4 electronic state. This study has demonstrated that PVP/ethanol/TiCl4 offers a facile, robust sol-gel related route for preparing supported TiO2 nanorod.