Constructing Anatase TiO2 Nanosheets with Exposed (001) Facets/Layered MoS2 Two-Dimensional Nanojunctions for Enhanced Solar Hydrogen Generation

Cocatalysts have been extensively used to accelerate the rate of hydrogen evolution in semiconductor-based photocatalytic systems, but the influence of interface state between semiconductor and cocatalyst has been rarely investigated. Here, we demonstrate a feasible strategy of two-dimensional (2D) nanojuctions to enhance solar hydrogen generation of the MoS2/TiO2 system. Loading of 2D MoS2 nanosheets on the surface of 2D anatase TiO2 nanosheets with exposed (001) facets greatly increases the interfacial contact. At an optimal ratio of 0.50 wt % MoS2, the 2D-2D MoS2/TiO2 photocatalyst shows the highest H-2 evolution rate of 2145 mu mol h(-1) g(-1), which is almost 36.4 times higher than that of pure TiO2 nanosheets. The apparent quantum yield of hydrogen evolution system reaches 6.4% at 360 nm. More importantly, the 2D-2D MoS2/TiO2 composite exhibits photocatalytic activity much higher than those of noble metal (such as Pt, Rh, Ru, Pd, and Au) loaded TiO2 photocatalysts. The decisive factor in improving the photocatalytic H-2 production activity is an intimate and large contact interface between the light-harvesting semiconductor and cocatalyst. The effective charge transfer from TiO2 to MoS2 is demonstrated by the significant enhancement of photocurrent responses in 2D-2D MoS2/TiO2 composite electrodes. This work creates new opportunities for designing and constructing highly efficient photocatalysts by interface engineering.