Anion–Anion Mediated Coupling in Layered Perovskite La2Ti2O7 for Visible Light Photocatalysis

Anionic–anionic (N–N, P–P, N–P, and C–S) mediated coupling can be introduced in the layered perovskite La2Ti2O7 structure for visible light photocatalysis. The anionic–anionic codoped La2Ti2O7 systems lower the band gap much more than their respective monodoping systems. Moreover, the electronic band positions of the doped systems with respect to the water oxidation/reduction potentials show that codoped (N–N, N–P, and C–S) systems are more promising candidates for visible-light photocatalysis. The calculated defect formation energy shows that the codoped systems are more stable than their respective monodoped systems.