Structuring phase junction between tri-s-triazine and triazine crystalline C3N4 for efficient photocatalytic hydrogen evolution.

Herein a novel carbon nitride composite with triazine-based crystalline carbon nitride (tri-C 3 N 4 ) vertically aligned on tri- s -traizine-based crystalline carbon nitride (tri- s -tri-C 3 N 4 ) is first proposed for efficient visible light driven (λ > 420 nm) photocatalytic H 2 evolution. The well matched lattice fringes between (002) plane of tri- s -tri-C 3 N 4 and (102) plane of tri-C 3 N 4 characterized by TEM unambiguously demonstrate the successful construction of tight crystalline junction between tri- s -tri-C 3 N 4 and tri-C 3 N 4 . As a result, the crystalline carbon nitride phase junction (tri-/tri- s -tri-C 3 N 4 ) shows a high visible light photocatalytic H 2 evolution activity of 144 μmol/h, which is 30 times higher than that of pristine g-C 3 N 4 . This outstanding photocatalytic H 2 evolution performance could be attributed to the fact that the construction of crystalline tight junction can greatly enhance the transfer and separation efficiency of photoinduced carriers. This study may provide a new way for rational design of carbon nitride heterojunction for gaining high photocatalytic activity. [ABSTRACT FROM AUTHOR]