A universal in situ lattice sulfidation synthesis method of metal sulfides/TiO2 heterostructures and its application in photocatalytic NO removal.

• A universal in situ lattice sulfidation synthesis method of MS x /TiO 2 was developed. • 8 kinds of MS x /TiO 2 (M = Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd) were prepared by the method. • Mn+ in MTiO 2 lattice reacted with S species to generate MS x in situ on TiO 2 surface. • CdS combined tightly with TiO 2 through chemical bonds rather than physical contact. • The tightly bonded heterostructure enhanced the photocatalytic activity dramatically. It is a challenge to synthesize well-defined metal sulfides/TiO 2 (MS x /TiO 2) heterostructures because of the lattice mismatch between MS x and TiO 2. In this work, an in situ lattice sulfidation synthesis method of MS x /TiO 2 was developed. Under hydrothermal conditions, metal atoms in metal-doped TiO 2 (MTiO 2) reacted with S species to generate MS x in situ on TiO 2 surface. This method is a universal preparation method and 8 kinds of MS x /TiO 2 heterostructures (M = Mn, Fe, Co, Ni, Cu, Zn, Mo and Cd) were synthesized. And taking CdS/TiO 2 as an example due to its highest photocatalytic activity, we can conclude that CdS grew tightly and dispersed uniformly on TiO 2 surface. The combination with CdS improved the photocatalytic NO removal ratio of TiO 2 greatly (>510 nm, from 2% to 34%; >400 nm, from 10% to 39%), which was high compared with other works. [ABSTRACT FROM AUTHOR]