Photocatalytic performance enhancement of two-dimensional Ruddlesden-Popper type perovskite K2La2Ti3O10 by nitrogen-doping

Abstract

Perovskite oxides have exhibited broad prospect of application in photocatalysis due to their high activity toward the oxygen evolution reaction and excellent stability in water. Although a variety of theoretical and experimental studies have been carried out during the past half-century, their practical applications are still restricted by the poor absorption of visible light and very low hole mobility. Here, by using first-principles calculations, we prove that the δ-nitrogen-doping is a powerful strategy to modulate the electronic structures of two-dimensional (2D) perovskite oxide K2La2Ti3O10. Our results demonstrate a significant enhancement of its photocatalytic and optoelectronic performance. Its bandgap becomes a direct one and decreases dramatically from 3.12 eV of 2D pristine K2La2Ti3O10 monolayer to 1.63 eV in its N-doping counterpart. Correspondingly, the calculated optical absorption spectrum shows a considerable improvement in the visible region (104 cm−1). Moreover, its hole effective mass also has a pronounced reduction from 26.1 to 0.346 m0, which increases the hole mobility greatly from 0.15 to 3.77 × 103 cm2V−1s−1.