Role of BaTiO₃ crystal surfaces on the electronic properties, charge separation and visible light–response of the most active (001) surface of LaAlO₃: A hybrid density functional study

Surface engineering has been proved as an efficient technique to boost charge separation and visible light absorption of semiconductor photocatalyst materials. Herein, we offer a first insight into the photocatalytic properties and electronic structure of cubic LaAlO₃(001) modified with cubic BaTiO₃ (001), (011) and (111) surfaces. Compared to the bulk LaAlO₃, the BaTiO₃/LaAlO₃(001) heterostructures showed superior redshift of absorption, work functions and a suitable staggered type–II band alignment to separate the photoinduced carriers. The BaTiO₃(001) surface coupled with LaAlO₃(001) surface show improved visible light photoactivity owing to the more surface complex and terminal barium atoms forming the main active adsorption sites on its surface. These findings offer new insight into the understanding of preferential exposure of photocatalytic active surfaces, which will aid in designing active heterostructures for photocatalytic reactions, as well as understanding the mechanism of photocatalysis.