Visible light photocatalytic degradation of malachite green using modified titania

Nanoparticles of titanium dioxide co-doped with carbon and iron (III) were prepared using the microemulsion method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Photoluminescence spectroscopy (PL), and UV-visible diffuse reflectance spectroscopy were used to characterize pure and doped TiO2 nanoparticles. Doped C atoms exist as the O–Ti–C structure or interstitial C in TiO2 lattice, while the doped Fe3+ atoms substitute some of Ti4+ to form the Ti–O–Fe structure. In comparison with the pure and C-doped TiO2, all C, Fe co-doped TiO2 samples exhibit a narrower band gap and stronger visible light absorption. The assistance of the C and Fe3+ ion enhances the photocatalytic activity in the visible light region and also inhibits the electron–hole recombination. The photocatalyst co-doped with C and 2.01 wt% Fe shows the excellent photocatalytic activity and degradation efficiency was improved by 78% under visible light irradiation as compared with the pure TiO2.