The O/S heteroatom effects of covalent triazine frameworks for photocatalytic hydrogen evolution.

S/O heterocyclic covalent triazine frameworks (CTFs i.e., CTF-7 and CTF-8) were synthesized using thiophene and furan as building blocks, respectively. The hydrogen evolution rate of CTF-7 is 7430 μmol g-1 h-1, which is about 5.6 times that of CTF-8. Due to their low electronegativity, sulfur heteroatoms are more favorable for charge separation than oxygen heteroatoms in CTFs. This work provides a guiding principle for the design of high efficiency photocatalyst structures.