Framework Ti-rich titanium silicalite-1 zeolite nanoplates for enhanced photocatalytic H2 production from CH3OH

Abstract

As a successful industrial catalyst, titanium silicalite-1 zeolite (TS-1) also possesses unique photocatalytic activity, but still challenging due to the unsatisfactory activity and unclear photocatalytic mechanism. Here, we achieved the optimization of TS-1 in both the morphology and content of framework Ti by a facile dual-structure directing agent method. The Ti-rich TS-1 nanoplates exhibit enhanced photocatalytic H2 production performance from methanol. The structure-activity relationship was revealed that the nanoplate-like morphology is beneficial to the photocatalytic activity, owing to the largely retainment of photogenerated electrons. Combined with in-situ DRIFTS and theoretical calculations, it is proposed that Ti−O group would function as a whole to serve as the active site, rather than separated Ti and O sites for reduction and oxidation half reactions respectively. The formation of hydroxylated Ti can also promote the photocatalytic performance. These insights into the mechanisms suggest the great potential of Ti-rich TS-1 nanoplates as commercial photocatalytic materials.