Construction of atomic-level charge transfer channel in Bi_(12)O_(17)C_(l2)/MXene heterojunctions for improved visible-light photocatalytic performance

摘要

Exploring efficient co-catalysts to accurately steer the charge separation of semiconductor photocatalysts is highly desired yet remains challenging.Here,we tackle the significant challenge by in situ growing the Bi_(12)O_(17)C_(l2)photocatalyst onto two-dimensional(2D)Cl-terminated Ti_(3)C_(2)MXene to construct 2D/2D heterojunction of Bi_(12)O_(17)C_(l2)and Ti_(3)C_(2).Firstly,2D few-layered Ti_(3)C_(2)MXene with chlorine groups has been successfully syn-thesized by Lewis acidic etching strategy with subsequent ultrasonic exfoliation.The grafting of chlorine terminations on the surface of MXene serves as nucleating centers and growth platform,resulting in the formation of strong interfacial bonds(Bi-Cl-Ti)between Bi_(12)O_(17)C_(l2)and Ti_(3)C_(2).These strong bonds can facilitate the separation and transfer of photo-generated charge carriers between Bi_(12)O_(17)C_(l2)photocatalyst and Ti_(3)C_(2)cocatalyst.As expec-ted,the photocatalytic degradation rate of Bi_(12)O_(17)C_(l2)/Ti_(3)C_(2)hybrids is 9.7 times higher than that of bare Bi_(12)O_(17)C_(l2)nanosheets.This work not only exhibits a new design concept to effectively steer the charge separation for photocatalysis,but also gives a reference for constructing efficient MXene-based photocatalytic systems.