Unraveling the Orientation of MoS2 on TiO2 for Photocatalytic Water Splitting

The heterostructure of 2D material with different orientations and TiO2 has been proven to be a good candidate for photocatalytic water splitting. However, the detailed mechanism of the orientation of 2D materials with TiO2 has not been explored. Herein, different combinations of edge-on MoS2 or basal-on MoS2 with TiO2 are investigated systematically. The adsorption energy, the activation energy barrier, as well as the charge distribution reveal that edge-on heterostructures have better efficiency in the separation of photoelectron-hole pairs and can enhance the efficiency of hydrogen evolution reaction. This work studies the differences in mechanisms of edge-on and basal-on heterostructures in hydrogen evolution reactions. The simulated results provide significant theoretical foundation for the design of new materials.