Single-Layered MoS2 Directly Grown on Rutile TiO2(110) for Enhanced Interfacial Charge Transfer.

Interfacial charge transfer is critical for the photocatalytic activities of compositional photocatalysts. In this work, we have developed a strategy of growing single-layer MoS2 sheets on the rutile TiO2(110) single-crystal surface using a chemical vapor deposition method. Both on-site and off-site characterizations confirmed the monolayer thickness and single crystallinity of the MoS2 adlayer as well as the atomic flatness of the composite surface. Without the presence of contamination, the charge flow across the interface of MoS2 and TiO2 is greatly enhanced, which hence favors the charge separation under excitations and boots up the catalytic activity of the composite system. Moreover, we found the luminescing property of MoS2 is significantly tailored upon coupling with the TiO2 surface. Our work has established a method for revealing the interface properties of the transition-metal dichalcogenides and oxide semiconductors at the atomic level.