Se-modified polymeric carbon nitride nanosheets with improved photocatalytic activities

The carbon nitride (CN) with selenide (Se) modification and porous thin nanosheet structure (m-CNNSs) has been successfully presented via an effective two-step continuous thermal treatment method. The as-prepared m-CNNSs show a photocatalytic H₂ generation and CO₂ reduction performance under visible light, the apparent quantum yield of H₂ generation (λ = 420 nm) reached 8.1%. This improved photocatalytic performance originates from the large surface areas and porous nanostructure that accelerated separation of photoexcited charge carriers and promoted mass-transfer process. Particularly, the formation of the Se modified in the thin CN sheets further endow it with reduced band gap, more exposed active edges, and extended visible light absorption range. This work not only presents a simple strategy to enhance the photocatalytic performance for CN, but also opens ups a new pathway for the rational preparation of effective polymeric photocatalysts by harnessing the synergistic effects to simultaneously optimize the electronic and frame structure of polymeric photocatalysts.