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

Abstract

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.

Keywords

• Surface engineering
• Type–II band alignment
• Photocatalysis
• Heterostructures
• Semiconductor