Titanium dioxide (TiO2) has been known as one of the most promising photocatalytic materials and attracted much attention due to its good stability, nontoxicity, high efficiency and low cost[1–3]. However, TiO2 with the wide band gap (Eg= 3.2 eV) can only absorb the near-UV light ( < 380 nm)[4], which greatly limits its practical applications. In order to overcome this shortcoming, the appropriate modifications such as non-metal doping and metal doping are essential for TiO2 to make maximum use of the visible-light region of sun. In the past few years, plenty of researches have been reported that doping TiO2 with non-metal elements, such as carbon, boron, fluorine and nitrogen demonstrated enhanced visible light photocatalytic activities [5–8]. Among them, nitrogen doping has been proved to be a simple and effective method to attain visible-light photocatalysis [9]. However, most of studies on nitrogen doped TiO2 considered that the nitrogen doping is only a surface or sub-surface modification and difficult to narrow the band gap in the bulk of TiO2, thus, it could only improve the visible light absorption in the range of 400–600 nm. It is really difficult to achieve the absorption in the wider region of 400–800 nm only by the heterogeneous nitrogen doping