Facile synthesis of SrNbO₂N nanoparticles with excellent visible-light photocatalytic performances

Perovskite-type SrNbO₂N nanoparticles with an average diameter of ∼40 nm were synthesized via a solvothermal method followed by post-nitridation treatment. The resultant SrNbO₂N nanoparticles have a narrow band gap of 1.94 eV, thus ensuring their visible light absorption. In particular, the photocatalytic studies revealed that the uniform SrNbO₂N nanoparticles exhibited high photocatalytic activity for H₂ evolution (H₂ release rate is 148.3 μmol h^-1 g^-1) and high degradation efficiency for methylene blue under visible light irradiation (λ>420 nm). The excellent photocatalytic activity can be attributed to the synergistic effects of the relatively small size nanoparticles with large specific surface area, the appropriate electronic structure as well as the efficient charge carrier separation. The preparation method has an important guiding significance for the synthesis of similar perovskite-type oxynitrides.