The spin-dependent recombination behavior of photogenerated charges has long been overlooked in the study of photocatalytic hydrogen (H2) evolution over covalent organic frameworks (COFs). Moreover, correlating the structure of COFs with the spin states of photogenerated charges to enhance photocatalytic H2 evolution performance remains a significant challenge. Herein, we present a chiral amino acid functionalization strategy to engineer chiral TpPa-1 COF for boosted photocatalytic H2 evolution. Following systematic optimization, the chiral TpPa-1 COFs showcased a ∼5-fold enhancement in photocatalytic performance, achieving a record TOF of 9867 h-1, alongside the second-highest reported AQY of 66% at 475 nm and HER of 2.54 mmol h-1 among the reported state-of-the-art COF-based photocatalysts for H2 evolution. Mechanism studies revealed that the synergistic effect between the chirality and the directional charge transfer allows efficient photo-generated charge separation. Furthermore, Chiral TpPa-1 assembled with polymeric carbon nitride (g-C3N4) in an S-scheme heterojunction can overcome the bottleneck in photocatalytic overall water splitting on g-C3N4 without oxygen evolution co-catalysts. In this work, we present a universal design strategy from a charge spin perspective to synthesize chiral photocatalysts for efficient photocatalytic performance.
Li et al. (Thu,) studied this question.