Boosting the Photocatalytic Ability of g-C3N4 for Hydrogen Production by Ti3C2 MXene Quantum Dots.

The big challenging issues in photocatalytic H2 evolution are efficient separation of the photoinduced carriers, the stability of the catalyst, enhancing quantum efficiency, and requiring photoinduced electrons to enrich on photocatalysts' surface. Herein, Ti3C2 MXene quantum dots (QDs) possess the activity of Pt as a co-catalyst in promoting the photocatalytic H2 evolution to form heterostructures with g-C3N4 nanosheets (NSs) (denoted g-C3N4@Ti3C2 QDs). The photocatalytic H2 evolution rate of g-C3N4@Ti3C2 QD composites with an optimized Ti3C2 QD loading amounts (100 mL) is nearly 26, 3 and 10 times higher than pristine g-C3N4 NSs, Pt/g-C3N4, and Ti3C2 MXene sheet/g-C3N4, respectively. The Ti3C2 QDs increase the specific surface area of g-C3N4 and boost the density of the active site. Besides, metallic Ti3C2 QDs possess excellent electronic conductivity, causing the improvement of carrier transfer efficiency.