Facile one‐pot hydrothermal method to prepare Sn(II) and N co‐doped TiO 2 photocatalyst for water splitting under visible light irradiation

Abstract In this paper, a visible light‐responsive Sn 2+ and N co‐doped TiO 2 photocatalyst was prepared by facile one‐pot hydrothermal method. All as‐prepared samples were characterized in detail by a series of characterization approaches. The results showed that the Sn 2+ and N elements were co‐doped into TiO 2 , while the catalyst still maintains anatase crystal structure and gets irregular little nanocluster in diameter of 9–10 nm with higher specific surface area. The absorption edge of Sn 2+ and N co‐doped TiO 2 extends to the visible light region. Compared with Sn 2+ ‐doped TiO 2 and N‐TiO 2 , the absorption edges have obvious red‐shift of about 50 and 70 nm, respectively. The synergistic effect of O 2p‐N 2p and O 2p‐Sn 5s hybridization to form impurity levels is the main reason for the red‐shift. The hydrogen production performance of the Sn 2+ and N co‐doping TiO 2 ( n (N)/ n (Ti) = 1) catalyst reached the maximum value of 0.37 mmol·h −1 ·g −1 under visible light, which is higher than that of N‐doped TiO 2 and Sn 2+ ‐doped TiO 2 singly. This result is due to the wider visible light region‐responsive ability of Sn 2+ and N co‐doped into TiO 2 . Furthermore, mild hydrothermal methods will not make the Sn 2+ oxidized to Sn 4+ , which make the catalysts still maintain high photocatalytic performance. This work provides a simple and mild method for the preparation of dual‐element co‐doped TiO 2 with high crystallinity, excellent performance and broad application prospects.