Monolayer Attachment of Metallic MoS₂ on Restacked Titania Nanosheets for Efficient Photocatalytic Hydrogen Generation

Monolayer attachment of metallic MoS2 (1T) on restacked titania (Ti0.87O20.52–) nanosheets was attained via a facile two-step flocculation process of their colloidal suspensions with the aid of the difference in critical H+ concentrations required for inducing flocculation of the respective nanosheets. The process produced porous flaky aggregates of restacked Ti0.87O20.52– nanosheets covered with monolayer MoS2, which serves as the electron collector and provides abundant catalytically active sites for proton reduction reaction. The MoS2-modified restacked Ti0.87O20.52– nanosheets showed a remarkably high photocatalytic efficiency for hydrogen generation (1.2 mmol h–1 g–1), being superior to those of the restacked Ti0.87O20.52– nanosheets and P25-TiO2 nanoparticles conventionally modified with MoS2 (0.38, and 0.4 mmol h–1 g–1, respectively). The extensive molecular-level interfacial coupling of Ti0.87O20.52–/MoS2 nanosheets facilitates efficient charge separation and fast electron transfer, resulting in the significantly enhanced photocatalytic activity.