Robust Photocatalytic Hydrogen Evolution Over a Conjugated Metal‐Organic Framework Heterojunction

ABSTRACT

Efficient photocatalysis requires the synergistic integration of charge separation and directional charge transport, yet achieving these features within a single framework remains challenging. Here, we report a conjugated coordination polymer, Cd‐TMT (TMT = 1,3,5‐trimercaptotriazine), featuring an intrinsic molecular‐level charge transport network. The conjugated TMT ligands facilitate strong intra‐ligand charge transfer, while their ordered π‐π stacking along the [111] direction establishes a continuous pathway for directional electron migration, endowing Cd‐TMT with intrinsic photocatalytic activity for hydrogen evolution. To further promote charge separation, Cd‐TMT is integrated with the conductive metal‐organic framework Cu‐HHTP (HHTP = 2,3,6,7,10,11‐hexahydroxytriphenylene) to construct a heterostructure. Spectroscopic investigations and density functional theory calculations demonstrate that this architecture accelerates charge separation while retaining highly reductive electrons. As a result, the Cd‐TMT@Cu‐HHTP composite achieves a H ₂ evolution rate of 9692.83 µmol g ⁻¹  h ⁻¹ , surpassing most reported MOF‐based photocatalysts. This work provides fundamental insights into molecular‐level charge transport and offers a viable strategy for designing high‐performance heterostructures for solar‐to‐fuel conversion.