A Schottky junction breakthrough for photocatalytic hydrogen evolution

Abstract The development of photocatalysts that combine high efficiency, durability, and visible‐light responsiveness remains a central challenge for solar‐to‐hydrogen conversion. In a recent study, Cabrero‐Antonino et al. report a 2D/2D Schottky heterojunction constructed from ultrasmall Cu 2 [CuTCPP] MOF nanosheets and conductive Ti 3 C 2 MXene. This hybrid interface generates a built‐in interfacial electric field that promotes directional charge transfer, suppresses recombination, and significantly prolongs carrier lifetimes, as evidenced by femtosecond transient absorption spectroscopy. The MXene component not only functions as a hole acceptor to improve charge separation but also mitigates photooxidative degradation of the MOF, thereby enhancing long‐term stability. The optimized heterojunction achieves a hydrogen evolution rate exceeding 5000 μmol g −1 under visible light, nearly 20 times higher than that of pristine MOF, with notable operational durability. These findings demonstrate the critical role of interfacial engineering in achieving synergistic charge dynamics across hybrid architectures. The work provides a scalable, sustainable strategy for noble‐metal‐free photocatalysis, offering valuable insights for the rational design of next‐generation systems for water splitting, CO 2 reduction, and solar‐driven chemical transformations.