Weakened Crystalline SnNb O for Enhanced Performance in Photocatalytic H Production and CO Reduction.

Low crystalline photocatalysts with unsaturated active sites, such as oxygen vacancy (O ), is reported to exhibit enhanced adsorption and activation of oxygen-containing small molecules, such as H O and CO , thus boosting the activity in photocatalytic H evolution and CO reduction. However, numerous low-crystalline photocatalysts show unsatisfactory stability due to the easily repaired surface O . Herein, three SnNb O with different crystallinity were prepared by hydrothermal approach with similar precursors. Compared with bulk SnNb O and ultra-thin layered SnNb O , low-crystalline SnNb O (SNA) exhibits optimal visible-light-driven evolution rates of H (86.04 μmol g  h ) and CO from CO (71.97 μmol g  h ), which is mainly ascribed to the fast separation of the photogenerated carriers and enhanced photoreduction power caused by the surface O . More importantly, the sharp decrease of photocatalytic activity of SNA after seven cycles is well restored by the hydrothermal treatment of recycled SNA, ascribed to the reactivated surface O with the recovered low-crystalline structure. These works thus offer a promising strategy for developing low-crystalline and amorphous photocatalysts with high activity and stability.