Among many candidates of semiconductor photocatalyst,titania(Ti02)has become the most investigated one for overall water splitting for hydrogen production,due to its outstanding chemical stability,low cost,and non-toxicity [1-3].However,the photocatalytic water splitting for hydrogen production of Ti02 are restricted to ultraviolet(UV)-light(λ< 385 nm)due to the wide band gap of anatase Ti02(~3.2 eV).Therefore,reducing the band gap of anatase Ti02 to make it photosensitive to visible-light has become one of the most important goals in photocatalytic water splitting for hydrogen production.We have investigated the electronic and optical properties of(Si,Fe)-codoped Ti02 based on density functional theory calculations.The calculated results indicate that the synergistic effects of(Si,Fe)codoping may further reduce the electrons excited energy from VB to CB compared with the pure Ti02 under the solar light irradiation,which enhances the photocatalytic activity for hydrogen production by water splitting and induces the redshift of absorption edge.The photocatalytic splitting water and absorption spectra obtained by experiments indicate that(Si,Fe)-codoped Ti02 sample has a much stronger absorption of the solar light and photocatalytic activity for hydrogen production by water splitting than the pure Ti02,which verifies the reliability of the calculation results.