Construction of NH₂‐UiO‐66@PCN‐224 Nanocomposites with Tightly Integrated Interfaces for Boosting Photocatalytic CO₂ Reduction with H₂O

Converting CO₂ into high‐value‐added products via “artificial photosynthesis” under mild conditions is a promising yet challenging strategy for developing efficient photocatalysts. This study reports a simple two‐step solvothermal approach to fabricate the dual‐metal–organic framework (MOF) nanocomposite NH₂‐UiO‐66@PCN‐224 (NU‐66@PCN‐224) with tightly integrated interfaces, which achieves efficient CO₂ to CO photocatalytic reduction under light irradiation. The epitaxially grown PCN‐224, composed of Zr₆ clusters and tetrakis (4‐carboxyphenyl) porphyrin (TCPP), serves as a shell layer and a visible light‐absorbing antenna, thereby broadening the light absorption range of the composite material. Moreover, the tightly integrated interfaces of NU‐66@PCN‐224 enhance the mobility of photogenerated charge carriers, consequently enhancing its capability for CO₂ catalytic reduction. As a result, the combination of NU‐66 and PCN‐224 retains their individual advantages while achieving a synergistic enhancement of both adsorption and catalysis, further improving the photocatalytic performance. The as‐prepared NU‐66@PCN‐224 catalyst exhibits outstanding photocatalytic performance, yielding 74.6 μmol g⁻¹ h⁻¹ of CO under irradiation without sacrificial agents or photosensitizers. This work demonstrates a straightforward and effective method for designing MOF‐on‐MOF photocatalysts with enhanced photoactivity.