LaTaON2-SrZrO3 solid solutions with tunable band gap for photocatalytic water oxidation under visible light illumination

Complete solid solutions between LaTaON 2 and SrZrO 3 , i.e. (LaTaON 2 ) 1−x (SrZrO 3 ) x (0 ≤ x ≤ 1) have been built which are very useful in tailoring many important parameters of LaTaON 2 . Band gap of LaTaON 2 becomes tunable by controlling the level of solid solutions with SrZrO 3 . Structural distortions, defects (e.g. Ta 4+ species) concentration and surface hydrophilicity of LaTaON 2 are largely improved by introducing SrZrO 3 in the structure. These modifications contribute to much enhanced photocatalytic activities of solid solutions for oxygen production which clearly outperform pristine LaTaON 2 under visible light illumination. Apparent quantum efficiency as high as 0.87% at 420 ± 20 nm was achieved at (LaTaON 2 ) 0.6 (SrZrO 3 ) 0.4 (x = 0.4). Further analysis suggest that introducing SrZrO 3 results in realignment of band edge positions of LaTaON 2 so as to be more appropriate for water splitting reactions.