Visible light-driven photocatalysis of W,N co-doped TiO2

W, N co-doped TiO₂ nanoparticles were synthesized by a sol–gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectrophotometry (DRS). The results showed that the co-doped photocatalysts were essentially uniform spherical particles with the smallest particle size of 22.5 nm. Compared to un-doped TiO₂, N-TiO₂ and P-25, the absorption edge of the W, N co-doped TiO₂ shifted to longer wavelength and its photocatalytic activity for degradation of methyl orange (MO) under Xe-lamp (350 W) was higher.