Resolving the Luminescence–Photocatalysis Trade‐Off via Interfacial Carrier Partitioning

Luminescence and photocatalysis rely on opposite carrier fates: emissive‐state preservation and interfacial charge extraction. This intrinsic conflict makes it difficult to amplify both functions within a single photoactive material. Here, we report an interfacial carrier‐partitioning strategy that coordinates emissive‐state stabilization with catalytic electron utilization within electronically coupled domains in a metal–organic framework (MOF) heterostructure. In NU‐902@Pd@CeO 2 , NU‐902 harvests photons and provides emissive centers, the CeO 2 buffers carriers and passivates nonradiative traps, while Pd mediates electron extraction and interfacial redistribution. In situ spectroscopy and density functional theory calculations reveal that the Pd–CeO 2 interface regulates electron extraction, emissive‐state relaxation, and oxygen activation. As a result, the heterostructure simultaneously enhances red emission and visible‐light photocatalysis, enabling interference‐resistant pollutant monitoring (100‐fold higher sensitivity), rapid removal, and continuous solar‐driven water treatment. The transferability of this design is further supported by representative sensing and remediation demonstrations. This work establishes interfacial carrier partitioning as a general design principle for multifunctional photoactive materials.