Novel SrTiO(3)/NaTaO(3) and visible-light-driven SrTiO(3)/NaTaO(3):N nano-heterojunctions with high interface-lattice matching for efficient photocatalytic removal of organic dye

SrTiO(3)/NaTaO(3) (STO/NTO) heterojunction photocatalysts were successfully constructed by decorating NaTaO(3) nanocubes with SrTiO(3) nanoparticles via a hydrothermal method. The structure of the perovskites NaTaO(3) and SrTiO(3) bear some resemblance to each other, which increases the interface lattice match for promoting the migration of photogenerated carriers between the STO/NTO interfaces. In comparison to pristine NaTaO(3) and SrTiO(3) samples, the STO/NTO composites exhibited remarkably improved capacity for the degradation of rhodamine B (RhB) under ultraviolet (UV) light (λ < 400 nm) irradiation. Furthermore, the partial replacement of O(2−) by N(3−) in the TaO (6) octahedron narrowed the band gap of NaTaO(3), which significantly enhanced the photocatalytic performance of the SrTiO(3)/NaTaO(3):N (STO/NTON) heterojunction under visible light (λ > 400 nm). Finally, the possible band structures of the STO/NTO and STO/NTON photocatalysts were proposed, which indicated that an n–n type heterojunction was constructed with a staggered gap for fast separation of photogenerated electron–hole pairs.