Exploring the impact of modulation of electronic structure via doping in the realm of environmental applications

• Study on effect of site occupancy of Ag in BaTiO 3 on the electronic structure. • Unique behaviour of Ag where mixed occupancies prevent formation of mid gap acceptor states. • 99.2 % photocatalytic degradation of rose bengal dye in 40 minutes. • 99 % photocatalytic degradation of malachite green dye in 50 minutes. Engineering the electronic structure of a material is quite a fascinating field of study as it not only helps in improving the performance of the material but also helps us understand why a particular combination of elements exhibits the properties it does. Substitutional doping has been receiving increasing interest in the field of photocatalysis for boosting the performance of the material by tuning its crystal structure and electronic structure. In this study, we report the effect of site occupancy of silver in Ag doped BaTiO 3 . First principles density functional theory calculations highlight that the Ti site which is the preferred site in BaTiO 3 for most of the dopants is not so preferred in the case of Ag doping for enhancing the photocatalytic activity. It also reveals the exceptional behavior of Ag where in it prevents the formation of mid gap recombination centers in the case of mixed occupancy. Doped samples synthesized through solvothermal approach with directed doping shows activity of 99.2 % and 99 % degradation of rose bengal and malachite green dyes in 40 and 50 minutes, respectively.