Band gap engineering of compensated (N, H) and (C, 2H) codoped anatase TiO2: A first-principles calculation

The electronic structures and optical properties of non-compensated (C, H)-, compensated (N, H)- and (C, 2H)-doped anatase TiO2 have been investigated using spin-polarized density functional theory. The calculated results indicated that compensated (N, H) codoped TiO2 exhibited the enhanced optical absorption under visible-light irradiation in comparison with N doped TiO2 and pure TiO2. Compensated (C, 2H) codoped TiO2 may also be a good candidate for visible-light photocatalyst materials due to the band gap narrowing significantly and the elimination of some local states.

Optical absorption curves calculated for different kinds of TiO2. The inset in figure shows the enlarged optical absorption spectrum with the wavelength ranging from 340 to 440 nm.130Highlights► Compensated codoping is favorable under Ti-rich growth conditions. ► N/H codoping gives rise to a much more effective band gap narrowing than N doping. ► C/2H codoping may be a good candidate for visible-light photocatalyst materials.