One-pot synthesis and Nb4N5 surface modification of Nb(4+) 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 Nb(4+) 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 Nb(4+) 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.