2D Ti₃C₂ as electron harvester anchors on 2D g-C₃N₄ to create boundary edge active sites for boosting photocatalytic performance

Control and insight into active sites and charge transport behaviors are challenging topics for fabricating heterojunction photocatalyst and investigating photocatalytic reaction mechanism. Herein, the 2D/2D Ti₃C₂/g-C₃N₄ heterojunctions are fabricated in the semi-closed system, in which the interaction at heterointerfaces is enhanced to improve the stability. Furthermore, 2D Ti₃C₂ not only serves as electron harvester to propel the directed transfer of photogenerated electrons from 2D g-C₃N₄ to 2D Ti₃C₂ and the high-efficiency separation of charge carriers, but also creates the boundary edge active sites on its surface, thus enhancing the photocatalytic performance. The photocatalytic reaction mechanism for H₂ production and degrading tetracycline hydrochloride (TH-HCl) are also revealed in detail, including identification of active sites, transport behaviors of charge carriers, generation of active species and intermediates, reaction ways, etc. This work provides a significant reference for the design, fabrication and mechanism insight of 2D/2D heterojunction materials in the photocatalytic application.