Ba-Modified LaTiO2N as an Efficient Visible Light Active Photocatalyst for Water Oxidation

LaTiO2N has been considered as one of the most promising photocatalysts for solar energy conversion. Nevertheless, it generally has a poor photocatalytic activity under normal conditions, probably linked to severe structural distortions and various types of defects within this compound. Herein, we modified LaTiO2N by introducing Ba into its A site, that is, La0.8Ba0.2TiO2.2N0.8. The presence of Ba at the A site of LaTiO2N not only relaxes the structural distortions but also effectively inhibits defect formation (e.g. Ti3+ species) in LaTiO2N. Moreover, surface hydrophilicity of LaTiO2N is also improved by Ba modification. Photoelectrochemical analysis suggests that charge separation and transferring situation are ameliorated in Ba-modified LaTiO2N, and the valence band edge position is positively shifted. These factors are likely the reasons for the improved photocatalytic activity of La0.8Ba0.2TiO2.2N0.8 in water oxidation reactions.