W18O49 Frameworks Decorated with Graphitic Carbon Nitride Quantum Dots for Photocatalytic Hydrogen Production

Quantum dots (QDs) have exhibited remarkable advantages for photocatalytic H-2 evolution. Unfortunately, despite their unique quantum size effects and abundant catalytic active sites, many applications of QDs have been hindered in that they are prone to aggregation and easy to leach off from the substrate. Therefore, it is highly desirable to fabricate a special nanostructure with confinement effects to conquer their intrinsic drawbacks. Herein, we present a direct g-C3N4-x/W18O49 Z-scheme nanocomposite for enhanced photocatalytic H-2 production. This system is composed of a W18O49 framework with several microporous slits and g-C3N4 QDs with a rich nitrogen vacancy. These several microporous slits can fix QDs and avoid their aggregation. Besides, the microporous slit surface can be functionalized by adjusting the pH value, thus ensuring intimate contact between W18O49 framework and g-C3N4-x QDs. The unique Z-scheme confinement structure facilitates photoinduced carrier transfer and improves the photocatalytic H-2 production performance. The g-C3N4-x/W18O49 nanocomposite exhibits an exceedingly high H-2 evolution rate and super stability because of the confinement structure and effective charge channel. This study provides a strategy to design the high-efficiency catalysts for solar H-2 production.