Visible light photocatalytic activity of TiO2 nanoparticles modified by pre-oxidized polyacrylonitrile

► TiO2 nanoparticle modified by pre-oxidized polyacrylonitrile (PO-PAN) was prepared. ► PO-PAN possesses a cyclied ladder structure with conjugated groups. ► The catalyst was tested in degradation of RBR X-3B under visible light irradiation. ► TiO2/PO-PAN shows much better visible light activity than that of neat TiO2.