Removal enhancement of acid navy blue dye by GO - TiO2 nanocomposites synthesized using sonication method

Abstract

This work analyses the removal of acid navy blue using GO-TiO2 nanocomposite, which is a next generation photocatalyst due to its fascinating optical properties. Pure TiO2 nanoparticles have been synthesized by the hydrolysis of Titanium tetra isopropoxide while GO was prepared by improved Hummer's method. GO-TiO2 nanocomposites with different concentrations of GO (in wt%) were synthesized using ultrasonic mixing of GO and TiO2 suspensions. The structural and optical properties have been analysed using X-ray diffraction, UV–Vis spectroscopy, FTIR spectroscopy, Raman and TEM analysis. The crystallite size of the synthesized nanocomposites was found to be in a range of 3 nm–7 nm. XRD patterns confirm the tetragonal anatase structure of TiO2. TEM analysis confirms the formation of fine spherical nanoparticles of TiO2 deposited over sheet like GO and the particle size correlate with that obtained from XRD graph. The photocatalytic properties of the nanocomposites have been analysed by the degradation of acid navy blue dye. It has been observed that the degradation time of the dye decreases for GO-TiO2 nanocomposite compared to the pure TiO2. This also implies that, the rate constant of the degradation of the dye is greater, for GO-TiO2 nanocomposite, than pure TiO2 nanoparticles. It was also found that the particle size decreases and rate constant gradually increases with the increase of GO concentration in the nanocomposites. This enhancement of photocatalytic property of TiO2 by GO can be used in wastewater treatment and industrial waste disposal.