Crystallization of Covalent Triazine Frameworks via a Heterogeneous Nucleation Approach for Efficient Photocatalytic Applications

Crystalline covalent triazine frameworks (CTFs) have shown intriguing applications in photoelectric fields. So far, a number of synthetic strategies based on homogeneous nucleation have been reported. However, it still remains a great challenge to acquire crystalline CTFs with wide structural diversity. Here, we report the synthesis of crystalline CTFs via a novel heterogeneous nucleation strategy, which exhibits a wide monomer scope. The crystalline CTFs could be successfully induced and grown on the lattice planes of salt, which works as a heterogeneous nucleation agent. The CTFs of different structures were successfully obtained with high degrees of crystallinity and nanosheet morphologies. These crystalline CTFs with structural diversity showed excellent activities in photocatalytic hydrogen evolution from sea water. The highest hydrogen evolution rate from "sea water"reached 791 μmol h-1 with a quantum yield of 12.8% under 420 nm irradiation. This work successfully demonstrated a new approach to synthesize crystalline CTFs with a wide monomer scope for photoelectric applications.