Integration of carbon dots and polyaniline with TiO2 nanoparticles: Substantially enhanced photocatalytic activity to removal various pollutants under visible light

In this study, ternary photocatalysts were fabricated through integration of carbon dots (CDs) and polyaniline (PANI) with TiO2 nanoparticles by a facile route. The photocatalysts were characterized by XRD, SEM, HRTEM, EDX, BET, XPS, FT-IR, UV-vis DRS, and PL instruments. Among the photocatalysts, the TiO2/CDs/PANI (20%) nanocomposite exhibited much higher photocatalytic performance for removal of RhB, MO, MB, and fuchsine in comparison with the TiO2, TiO2/CDs, and TiO2/PANI (20%) photocatalysts under visible light. The degradation rate constant of RhB by TiO2/CDs/PANI (20%) nanocomposite was 481 x 10(-4 )min(-1), which is almost 36.5 and 2.6 times more than those of the TiO2 and TiO2/CDs photocatalysts, respectively. It was confirmed that circle O-2(-) played predominant role in RhB degradation. Finally, the mechanism for enhanced photocatalytic activity was also discussed. The improved visible-light photocatalytic performance was related to substantial absorption of visible light, diminished recombination of the charge carriers, and enhanced specific surface area.