Plasmonic photothermal-assisted S-scheme photocatalyst for broad-spectrum solar hydrogen production

Exploiting the near-infrared (NIR) light which accounts for 50% of solar spectrum for broadband photocatalytic hydrogen evolution is an urgent need for energy crisis. In this work, WO 3 quantum dots (QDs) were decorated on ZnIn 2 S 4 nanoflowers to establish a S-scheme heterojunction. The localized surface plasmon resonance (LSPR) effect of WO 3 QDs not only extends light harvesting into the NIR region but also induces a plasmon-assisted photothermal effect, collectively enabling efficient visible-to-NIR photocatalytic hydrogen evolution. The optimal WO 3 /ZnIn 2 S 4 composite achieves a hydrogen evolution rate of 2920.84 μmol g −1  h −1 , approximately 34.35 and 1.69 times higher than those of pristine WO 3 and ZnIn 2 S 4 , respectively. Moreover, XPS, UV-Vis, and Mott-Schottky analyses confirm the formation of an internal electric field at the WO 3 /ZnIn 2 S 4 interface, which facilitates charge migration and suppresses electron–hole recombination. This work offers an effective strategy for designing highly active photothermal-assisted photocatalysts that respond efficiently to both visible and NIR light.