Visible-light-driven photocatalytic water oxidation over LaNbON2–LaMg2/3Nb1/3O3 solid solutions

Abstract

Solid solutions between LaNbON₂ and LaMg_2/3Nb_1/3O₃, i.e. (LaNbON₂)_1−x(LaMg_2/3Nb_1/3O₃)_x (0.0 ≤ x ≤ 1.0), have been investigated as photocatalysts for water oxidation into oxygen under visible light illumination (λ ≥ 420 nm). Many important parameters are strongly correlated with solid solution levels, including band gap, nitrogen content, defect concentration,band edge alignments, etc. This offers us a useful tool to steer photocatalytic performance among these solid solutions. Much improved photocatalytic activity is noticed for (LaNbON₂)_0.8(LaMg_2/3Nb_1/3O₃)_0.2 (x = 0.2), which gives an AQE as high as 0.53% at 420 ± 20 nm. This useful strategy by forming solid solutions opens new playgrounds full of opportunities for the design and development of efficient photocatalysts for solar energy conversions.