Investigation of structural, electronic and optical properties of (V+P)-doped BaZrO3 for photocatalytic applications using density functional theory

In the present study, we employ spin-polarized density functional theory for examining changes in the opto-electronic properties of wide band gap barium zirconate by incorporating Vanadium and Phosphorous dopants at Zr- and O-sites of BaZrO ₃, respectively. The generalized gradient approximation is used to compute thermodynamic and structural properties, while modified Becke-Johnson local density approximation is employed for the electronic and optical properties of pristine, mono-doped (V- or P-doped) and co-doped ((V + P)-doped) BaZrO ₃. The doping of a P atom at a O-site is found to cause shift in the valence band toward the conduction band; giving rise to an acceptor system with reduced band gap as compared to pristine BaZrO ₃. On the other hand, doping of V atom at a Zr-site leads to a donor system which modulates the conduction band of pristine BaZrO ₃. The charge compensated co-doping of V and P at neighboring Zr-site and O-site results in a band gap reduction of pristine BaZrO ₃ and is found to be suitable for absorbing solar radiations in the visible region of electromagnetic spectrum. The calculated electronic and optical properties of (V + P)-doped BaZrO ₃ together with positioning of the conduction and valence band edges with respect to water oxidation and reduction potentials make this material a potential candidate for hydrogen production through photocatalysis of water using solar radiations.