Photo-Decolorization of Dyes in Water Using Titanium Dioxide Nanoparticles Under Solar Radiation

Abstract

In this research work a feasible titanium dioxide photo-catalytic technology for removal of dyes from wastewater was explored in four stages; the synthesis and characterization of two catalysts, optimization of parameters influencing the photo-catalytic process, photo-decolortization process of four different dyes have been investigated to effect of each catalysts and kinetic studies of photo-decolorization of the dyes. The results showed that sol-gel method along with and using titanium tetrachloride as starting material is the best route to synthesize TiO2 nanoparticles with optimum properties. From X-Ray Diffraction (XRD) data analysis it was found that both TiO2 sol-gel which is prepared by sol-gel method and pure TiO2 are antase phase with the particles size of pure TiO2 (49.11070nm), TiO2 sol-gel (22.0198nm), having high crystallinity and purity. From Fourier Transform Infra-Red Spectroscopy (FTIR) data, the spectra of both TiO2 pure and TiO2 sol-gel have the same vibrations frequency (400 – 800cm-1) characteristic Ti—O, (1426-1696 cm-1) characteristic of (O—Ti—O) bond and (Ti = O) bond). The specific surface areas of pure TiO2 were (46.962 m²/g), TiO2 sol-gel (38.264 m²/g.). The adsorption isotherm exhibits type IV pattern with hysteresis loop, when the adsorption and desorption isotherm was evaluated using Brunauer-Emmett-Teller (BET) method. TiO2 sol-gel has optical absorption coefficient 0.99, extinction coefficient (1), the refractive index