Photocatalytic degradation of crystal violet dye on the surface of Au doped TiO2 nanoparticle

Abstract

The photocatalytic degradation of crystal violet (CV), which is a cationic triphenyl methane dye in aqueous solution has been investigated with colloidal suspension of Au doped TiO₂ under both UV and visible light irradiation and compared with undoped TiO₂. The degradation has been studied by UV-visible absorption spectroscopy and it is found that Au doped TiO₂ is highly efficient for the dye degradation. Doped and undoped titanium dioxide (TiO₂) nanoparticles have been prepared as a colloidal suspension using sol-gel hydrolysis method and are characterized by XRD, TEM, and UV-visible absorption spectroscopy. The UV-visible absorption spectra reveal that the intensity of the characteristic peaks of CV diminish with time and within an hour the intensity drop below 3/4^th of the maximum intensity and there is concomitant oxidative degradation of the dye. This process is accelerated under UV exposure.