Hierarchical In 2 S 3 microflowers decorated with WO 3 quantum dots: Sculpting S-scheme heterostructure for enhanced photocatalytic H 2 evolution and nitrobenzene hydrogenation

Solar energy conversion and high-value chemical production are of utmost importance. However, the development of efficient photocatalysts with strong redox ability remains challenging. Here we report a unique 3D/0D In 2 S 3 /WO 3 S-scheme heterojunction photocatalyst obtained by depositing WO 3 quantum dots (QDs) onto hierarchical In 2 S 3 microflowers. The In 2 S 3 /WO 3 composite exhibits outstanding visible light absorption, with a maximum optical response of up to 600 nm. The electronic interaction and charge separation at interfaces are explored by in situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. The difference in work function causes In 2 S 3 to donate electrons to WO 3 upon combination, leading to the formation of an internal electric field (IEF) at the interfaces. Due to the IEF and bent energy bands, the transfer and separation of photogenerated charge carriers follow an S-scheme pathway within In 2 S 3 /WO 3 . Owing to the strong redox ability, spatial charge separation and lower H 2 -generation barrier of S active sites, the optimized In 2 S 3 /WO 3 heterojunctions show enhanced photocatalytic hydrogen evolution of 0.39 mmol h -1 g -1 , 6.7 times that of pristine In 2 S 3 . In addition, the In 2 S 3 /WO 3 S-scheme heterojunctions afford a remarkable activity for photocatalytic nitrobenzene hydrogenation with nearly 98% conversion and 99% selectivity of aniline within 1 h. Our work might present new insights into developing efficient S-scheme heterojunctions for various photocatalytic applications.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.