One-pot synthesis and Nb₄N₅ surface modification of Nb⁴⁺ self-doped KNbO₃ nanorods for enhanced visible-light-driven hydrogen production

Herein, rhombohedral self-doped KNbO₃ (S-KN) nanorods were fabricated via a one pot, solvothermal method without using any surfactant. The presence of Nb⁴⁺ in S-KN greatly narrows its band gap and thus extends its photoresponse from UV to the visible light region. Moreover, S-KN/Nb₄N₅ nanorod heterostructures were obtained by nitriding S-KN nanorods for different times, which exhibited significantly enhanced photocatalytic activity for hydrogen production under visible light irradiation. The junction formed between S-KN and Nb₄N₅ and the Nb⁴⁺ self-doping of KN are supposed to be responsible for the enhanced photocatalytic activity of S-KN/Nb₄N₅. This study also paves the way for the synthesis of other similar photocatalysts.