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

Abstract

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.