Synthesis of WO3@WS2 core-shell nanostructures via solution-based sulfurization for improved performance of water splitting.

High light absorption capacity and excellent charge transportation are significant for superior water-splitting performance. Here, WO3/WS2 core-shell nanowire arrays were fabricated using a two-step hydrothermal method. The crystal phase, morphology, crystal structure, chemical composition, and optical properties were characterized using XRD, SEM, TEM, XPS, and UV-vis spectroscopy. Consequently, the photocurrent density of the as-prepared WO3/WS2 photoanode was 0.91 mA cm-2 (at 1.23 V vs. RHE), which showed a 112% increase compared to that with pristine WO3. The enhanced photoelectrochemical performance, we believe, was due to the promoted light response and improved separation as well as transportation at the WO3/WS2 interface.