Defect‐Induced Activity Enhancement of Self‐Exfoliated Carbon Nitrides for Solar Hydrogen Evolution

Abstract

AbstractThe recombination of photogenerated electron‐hole pairs severely limits the efficiency of solar‐driven hydrogen evolution in carbon nitrides (CN) system. Herein, a K+ doped and cyanamide defects modified CN (CCNK) with free‐standing nanosheets in water was synthesized by a bottom‐up self‐exfoliated strategy. Further experimental characterizations reveal that the cyanamide moiety and K+ in the framework play an important role in the enhancement of hydrophilicity and efficiently suppress electron‐hole pair recombination. CCNK exhibits an impressive photocatalytic hydrogen evolution activity (132.6 μmol h−1), which is 22 times higher than bulk CN (6.0 μmol h−1), and far surpassing other CN‐based photocatalysts. This work provides an innovative facile self‐exfoliated strategy for bottom‐up preparation of ultrathin CN nanosheets without using any acid, base, or solvents, paving the way for the development of high‐performance photocatalysts using CN‐based powders.