Synthesis of visible light-activated TiO2 photocatalyst via surface organic modification

A visible light-activated TiO2 photocatalyst was successfully synthesized by the surface organic modification to sol–gel–hydrothermal synthesized TiO2. The surface hydroxyls of TiO2 nanoparticles reacted with the active –NCO groups of tolylene diisocyanate (TDI) to form a surface complex that was confirmed by the FT–IR and XPS spectra. Due to the existence of surface complex, the absorption edge of as-prepared TDI-modified TiO2 nanomaterial extended well into visible region. Compared with unmodified TiO2 and Degussa P25, the TDI-modified TiO2 photocatalysts showed higher activity for the photocatalytic degradation of methylene blue under visible light irradiation.