A new triazine-based conjugated polymer from simple monomers with stable photocatalytic hydrogen evolution under visible light

A new triazine-based conjugated polymer THT-TA was constructed with simple building blocks 2,4,6-trihydrazino-1,3,5-triazine (THT) and terephthalaldehyde (TA) via solvothermal reaction. The structural characterizations confirmed the successful synthesis of the polymer, and TEM images clearly revealed the sheet-like morphology. The 2D layered structure was further confirmed by XRD , and the semi-crystalline pattern was better fitted with a novel parallelogram framework rather than classic hexagonal framework. The optical band gap of THT-TA was 2.50 eV, and the frontier orbitals were delocalized across the framework from DFT calculation, validating that higher degree of conjugation was achieved from small monomers . The photocatalytic hydrogen evolution was successfully achieved with Pt as co-catalyst and sodium ascorbate as sacrificial agent under visible light (λ > 420 nm), and the sample showed considerable stability in the long-term test for more than 200 h.