Density functional theory study on the structural, electronic, optical and photocatalytic properties of BaTa2O6, Ba2Ta15O32, Ba3Ta5O15 and Ba5Ta4O15

By means of density functional theory calculations, we investigated the structural, electronic, optical properties and photocatalytic activity of BaTa2O6, Ba2Ta15O32, Ba3Ta5O15 and Ba5Ta4O15 four barium tantalum oxides and made a comparative study of them. The results show that these four compounds are indirect band gap semiconductors and the interactions between atoms are weak. They show the superior absorption performance in the ultraviolet region, especially Ba2Ta15O32 and Ba3Ta5O15. Among the four compounds, BaTa2O6 and Ba3Ta5O15 have the electrons mobility and the recombination rate of the electron-hole pairs in the G -> K and G -> X directions, respectively. They have the superiority in degrading organic pollutants, especially BaTa2O6 on account of its highest valence band potential. Because of the excellent absorption performance and suitable band edge position, it is predicted that BaTa2O6, Ba3Ta5O15 and Ba5Ta4O15 should have the better photocatalytic activity compared with Ba2Ta15O32.

Automated summary

Through density functional theory calculations, it was found that barium tantalum oxides are indirect band gap semiconductors with weak atomic interactions and superior absorption performance in the ultraviolet region. Among them, BaTa2O6 and Ba3Ta5O15 exhibit advantages in electron mobility and photocatalytic activity.