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.