Calculations show improved photoelectrochemical performance for N, Ce, and Ce + N doped anatase TiO2

Abstract

The effect of substitutional N, Ce, and Ce + N doping on the electronic structure and optical properties of anatase TiO2 have been investigated by using first-principles calculations and considering the strong correlation effect. It is found that Ce + N doping results in bandgap narrowing and also leads to a red-shift of the absorption edge of TiO2, which could meet the demand for water splitting. The decreases in the bandgap are 0.47 eV, 0.21 eV, and 1.05 eV by N, Ce, and Ce + N doping, respectively. Magnetism appears in N and Ce + N doped TiO2, which is attributed to the mismatch between the spin up and spin down states of O-2p, N-2p, and Ce-4f (for Ce + N doped). We predict that Ce + N doping is one of the best choices for enhancing the photoelectrochemical activity of TiO2.