Ordered porous nitrogen-vacancy carbon nitride for efficient visible-light hydrogen evolution

Abstract

Photocatalytic H2 evolution is a promising technology which could be instrumental in producing clean hydrogen energy. In regard to the photocatalyst, its band structure, morphology and light utilization have a significant influence on the H2 evolution rate and stability. Herein, a three-dimensional ordered macroporous nitrogen-vacancy carbon nitride (3DOM V-CN) photocatalyst was developed by combining vacancies with 3DOM structure for visible-light photocatalytic H2 evolution. This strategy preserved the structural properties of 3DOM to improve the light utilization and the specific surface area of the photocatalysts. Moreover, constructing suitable vacancies could trap electrons to facilitate the separation of photogenerated carriers, and extend the light absorption region of the photocatalysts by adjusting band structure, thus improving photocatalytic activity. Compared with CN (0.3 mmol h−1 g−1), 3DOM V-CN demonstrated a superior photocatalytic H2 evolution rate of 2.3 mmol h−1 g−1 (λ ≥ 420 nm) while possessing excellent stability. This work provides an effective and low-cost strategy for the design of the photocatalysts with high activity and stability by simultaneously tuning the band structure and morphology.