The optical absorption and hydrogen production by water splitting of (Si,Fe)-codoped anatase TiO2 photocatalyst

The electronic and optical properties are studied using the density functional theory in (Si,Fe)-codoped anatase TiO2. The calculated results suggest that the synergistic effects of (Si,Fe) codoping can effectively induce the redshift of optical absorption edge, which leads to higher visible-light photocatalytic activity for hydrogen production by water splitting than pure anatase TiO2. To verify the reliability of our calculated results, nanocrystalline (Si,Fe)-codoped TiO2 is synthesized by a sol-gel-solvothermal method, and excellent absorption performance and photocatalytic activity for hydrogen production by water splitting are observed in our experiments.

► Si doping TiO2 induces an obvious band gap narrowing by mixing O 2p with Si 3p.
► Fe doping TiO2 leads to a band gap narrowing and an impurity states Fe 3d appearing.
► Synergy of codoping TiO2 induces excellent photocatalytic activity for H2 production.
►  Our calculated results are firstly verified by our experimental observation.