MoS Quantum Dots@TiO Nanotube Arrays: An Extended-Spectrum-Driven Photocatalyst for Solar Hydrogen Evolution.

TiO nanotube arrays (TiO NTAs) decorated with molybdenum disulfide quantum dots (MoS QDs) were synthesized by a facile electrodeposition method and used as a composite photocatalyst. MoS QDs/TiO NTAs showed enhanced photocatalytic activity compared with pristine TiO NTAs for solar light-promoted H evolution without adding any sacrificial agents or cocatalysts. The photocatalytic activity was influenced by the amount of MoS QDs coated on TiO NTAs. The optimal composition showed excellent photocatalytic activity, achieving H evolution rates of 31.36, 5.29, and 1.67 μmol cm  h corresponding to ultraviolet (UV, λ<420 nm), visible (Vis, λ≥420 nm), and near-infrared (NIR, λ>760) illumination, respectively. The improved photocatalytic activity was attributed to the decreased bandgap and the surface plasmonic properties of MoS QDs/TiO NTAs, which promoted electron-hole pair separation and the absorption capacity for Vis and NIR light. This study presents a facile approach for fabricating MoS QDs/TiO NTA heterostructures for efficient photocatalytic H evolution, which will facilitate the development of designing new photocatalysts for environment and energy applications.