Intramolecular heterostructured carbon nitride with heptazine-triazine for enhanced photocatalytic hydrogen evolution.

[Display omitted] • Intramolecular heterostructured carbon nitride is successfully synthesized. • The as-prepared sample exhibits superior photocatalytic hydrogen production. • Rapid separation and transfer of photogenerated carriers in as-prepared sample. • The addition of salt mixture regulates the localized electronic structure. Efficient separation and transfer of photogenerated carriers is vital for efficient photocatalytic hydrogen evolution. We report development of a new type of intramolecular heterostructure graphitic carbon nitride with heptazine-triazine (CN-HT) by use of a one-step thermal polymerization method. This intramolecular heterostructure changes the electronic structure to promote charge transfer and enhances the adsorption of H*. The as-prepared CN-HT exhibits superior photocatalytic hydrogen evolution of 88.29 μmol/h, which is 14.2 times that of pristine CN. The apparent quantum yield is 10.1% at 400 nm and 9.6% at 450 nm. The efficient separation and transfer of photogenerated carriers as well as the expanded visible light absorption in this intramolecular CN heterostructure contribute to the efficient utilization of photogenerated carriers, thus enhancing the photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]