Composite structures for enhanced photoelectrochemical activity: WS2 quantum dots with oriented WO3 arrays

Novel visible-light-driven WO 3 nanorod arrays with oriented (200) facet were successfully synthesized via a facile solvothermal process using mixed ethanol and water as solvents. Subsequently, WS 2 quantum dots (QDs) derived from bulk WS 2 powder via ultrasonication were interspersed on WO 3 nanorod arrays. The presence of suitable volume ratio of ethanol is a key factor to achieve greater exposure of the WO 3 (200) facet. The morphologies, microstructures and optical properties of the prepared samples were systematically explored. The results illustrated that the preferential exposure on the (200) facet of WO 3 nanorods as well as the efficient relative electrochemically active surface areas provided by WS 2 QDs could facilitate the charge transfer between WS 2 QDs and the (200) facet of WO 3 nanorods. This study provides a promising approach to design high performance photoanodes for photoelectrochemical water splitting.