Enhanced optical absorption and photocatalytic activity of anatase TiO₂ through C-- Nd-codoped: A DFT+U calculations

The electronic and optical properties are investigated using density functional theory plus U approach in C[sbnd]Nd monodoped and codoped anatase TiO₂. The calculated results indicate that C dopant can enhance the intensity of optical absorption and Nd dopant can extend the optical absorption range into the whole visible spectrum in C[sbnd]Nd-codoped anatase TiO₂, and the Nd 4f states can effectively reduce the recombination of photo-excited electron-hole pairs thus achieving higher visible light photocatalytic activity for hydrogen production by water splitting than pure TiO₂. Moreover, we also study the effects of doping concentration and impurity distance in C[sbnd]Nd-codoped anatase TiO₂ system, finding that the higher doping concentration, the stronger absorption activity, and absorption activity increases with the shortness of impurity distance due to the assemblage of impurity states.