Solar light-driven photocatalytic degradation of methyl blue by carbon-doped TiO2 nanoparticles

Sol-gel method was used to synthesize carbon doped TiO2 nanoparticles with excellent photocatalytic activity under solar light irradiation. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrophotometer (FTIR), and UV–vis spectrometer were used to analyze the absorption spectra and methyl blue concentration in water at different time intervals throughout the photodegradation experiment. The results revealed that pure TiO2 and carbon doped TiO2 nanopowders are anatase phase with crystallite sizes ranging from 8 to 13 nm. The doping was found to decelerate the grain development of the nanopowder. Although carbon doping in TiO2 may effectively expand the light absorption capabilities towards visible light, too much doping is deleterious to light absorption ability. The optimal doping quantity for maximum photocatalytic degradation of MB in our experiment was 2 atoms %; above this doping, the catalyst's photocatalytic activity diminishes.