First-principles calculations of the electronic structure and optical properties of K1−xNaxTaO3 (x=0, 0.25, 0.5, 0.75, 1)

The first-principles calculations are performed to investigate the cubic phase composite K1−xNaxTaO3(x=0, 0.25, 0.5, 0.75, 1), by using density functional theory (DFT) with the full potential linearized augmented plane wave (FP-LAPW) method. The energy band structures, density of states (DOS), electron density and optical properties are obtained. The results show that Na ion plays an important role in K1−xNaxTaO3. With the content of Na ion increasing, the changes of lattice parameters, energy gaps, bond lengths and optical properties of K1−xNaxTaO3 are regular. Moreover, the dependence of ferroelectric photocatalysis on both optical properties and internal electronic structure are analyzed in detail. It is proposed that the doped materials are promising photocatalytic materials.