Visible-light photocatalytic degradation of ethidium bromide using carbon- and iron-modified TiO2 photocatalyst

Abstract

Nanosized TiO2 as well as carbon (C) and C, Fe co-doped TiO2 were synthesized using reverse microemulsion method. Thermal stability of precursor was studied using thermogravimetry and differential thermal analysis techniques. Heat-treated powders were characterized using Fourier transform infrared spectrophotometer, X-ray diffractometer, scanning electron microscope, transmission electron microscope and energy-dispersive X-ray spectroscope. Visible-light photocatalytic degradation of aqueous solution of ethidium bromide (EtBr) was investigated using C, Fe co-doped TiO2 photocatalyst. UV–visible spectrophotometer and high-pressure liquid chromatography techniques were used to analyze the concentration of EtBr during the degradation process. Various parameters affecting the photocatalytic activity of photocatalyst are studied. C-doped TiO2 acts as photosensitizer and helps to extend the light absorption wavelength of C-doped TiO2.·Fe co-doping introduces new energy levels of the transition metal ions between the band gap of TiO2 and further extends absorption wavelength in visible region. The synergistic effects of C- and Fe-modified TiO2 nanoparticles were responsible for improving visible-light photocatalytic activity.