Realigning the melon chains in carbon nitride by rubidium ions to promote photo-reductive activities for hydrogen evolution and environmental remediation

The photocatalytic efficiency of polymeric carbon nitride (PCN) suffers from unsatisfactory charge separation because of its amorphous structure. Herein, we report a simple bottom-up method to synthesize a novel structure of rubidium ion inserted PCN (Rb-PCN), which involves the regular alignment of melon chains to endow a crystalline feature in PCN. The insertion of Rb+ decreased not only the N p electrons in the heptazine ring but also the plane angle of the heptazine motifs in the melon chain, which promoted the long-range periodicity and crystallinity of carbon nitride. This structurally rearranged crystalline Rb-PCN demonstrated considerably enhanced separation of charge carriers, resulting in six-fold higher photocatalytic hydrogen evolution activity than its amorphous counterpart. Furthermore, the photoexcited electrons can be efficiently trapped by O2 to generate H2O2, which facilitates the production of reactive oxygen species to inactivate bacteria and degrade organic pollutants, showing great potential for use in both energy and environmental applications.

Automated summary

A crystalline structure of rubidium ion inserted PCN was synthesized, which exhibited enhanced photocatalytic activity and potential for energy and environmental applications.