Facile synthesis of spherical Au/TiO2 nanoparticles by sol-gel method using Tween 80 for photocatalytic decolourization of Malachite Green dye

Abstract

The current study demonstrated the successful photocatalytic decolourization of malachite green (MG) dye over novel spherical TiO2 nanocomposites embedding with 0–1 wt% of Au nanoparticles. Au/TiO2 nanocomposites were prepared by using sol-gel method and Tween 80 as a template. A shift in solution color from yellow to dark purple color was spontaneously detected after addition of Tween 80 revealing the reduction of Au ions into metallic Au nanoparticles. The structural, crystalline and morphological features of the samples were characterized using X-ray diffraction, XRD, Field emission scanning electron microscopy, FESEM, together with energy-dispersive X-ray spectroscopy, EDX, and Fourier transform infra-red spectroscopy, FTIR,. The obtained characterization results indicate that the existence of Au nanoparticles control the growth of titania crystallites and reduce the crystallite size to nano dimensions. The photocatalytic reactivity of Au/TiO2 was found to be highly effected in the presence SnO2 as a co-dopant with Au. DR UV-Vis study showed the disappearance of surface plasmon absorption in the presence of SnO2.