Photocatalytic and tunable optical absorption properties of sandwich-like p-n type LaBO3/KNbO3 (B = Al, Ga) heterostructures

Abstract

Photocatalytic efficiency enhancement through the construction of heterostructure interface in traditional materials is remain a significant challenge. In this paper, the photocatalytic properties of LaBO3/KNbO3 (B = Al, Ga，abbreviated as LBO/KNO) interfaces were investigated by building sandwich-like p-n type KNO/LBO/KNO heterostructures. Through the analyses of band alignment, the LaBO3/KNbO3 heterostructures with KO–KO, KO–NbO2, NbO2–KO and NbO2–NbO2 terminal can all be promised as photocatalysts for reduction reactions. Compared with the KO–NbO2 and NbO2–KO terminal, the absorption spectra of KO–KO terminal and NbO2–NbO2 terminal show obvious absorption peaks in visible-infrared region for LaBO3/KNbO3 heterostructures. With increasing the number of KNbO3 layers, the width of the pseudo band gap gradually decreases leading to a bathochromic shift of absorption peak. The absorption band eventually moves from ultraviolet to visible and infrared regions, which accounts for 92% of the total solar energy. Benefited from the construction of p-n heterojunction with special sandwich-like structure, the absorption photon achieves the energy interval modulation. Moreover, the unique LaBO3/KNbO3 interfaces enhance the absorption bandwidth and efficiency of solar energy, which may provide a novel pathway for design high-performance photocatalytic materials.