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.