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

The big challenging issues in photocatalytic H 2 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, Ti 3 C 2 MXene quantum dots (QDs) possess the activity of Pt as a co-catalyst in promoting the photocatalytic H 2 evolution to form heterostructures with g-C 3 N 4 nanosheets (NSs) (denoted g-C 3 N 4 @Ti 3 C 2 QDs). The photocatalytic H 2 evolution rate of g-C 3 N 4 @Ti 3 C 2 QD composites with an optimized Ti 3 C 2 QD loading amounts (100 mL) is nearly 26, 3 and 10 times higher than pristine g-C 3 N 4 NSs, Pt/g-C 3 N 4, and Ti 3 C 2 MXene sheet/g-C 3 N 4, respectively. The Ti 3 C 2 QDs increase the specific surface area of g-C 3 N 4 and boost the density of the active site. Besides, metallic Ti 3 C 2 QDs possess excellent electronic conductivity, causing the improvement of carrier transfer efficiency.