Coupling Robust 222 Rn Capture With Scintillation Readout in High‐Entropy Lanthanide‐Cluster Metal‐Organic Framework Scintillators

Efficient capture‐coupled detection of hazardous 222 Rn requires porous scintillators that integrate noble‐gas affinity, structural robustness, and radioluminescent readout under practical operating conditions. Here, we report two fluoride‐bridged, lanthanide‐cluster MOF scintillators, Tb‐LOF‐100 and Tb‐LOF‐101, together with their high‐entropy lanthanide‐node analogues (Ln‐LOF‐100 and Ln‐LOF‐101), to elucidate how high‐entropy node engineering regulates 222 Rn capture and radiation‐responsive performance. The high‐entropy MOFs retain the crystalline phases and permanent porosity of their Tb‐based parents, while exhibiting enhanced thermal, moisture, and γ‐irradiation stability. In particular, Ln‐LOF‐101 delivers a static 222 Rn uptake capacity of 46.1 Bq g −1 and a breakthrough adsorption coefficient of 10.9 Lg −1 for 222 Rn, ranking among the best‐performing adsorbents reported for Rn capture under ambient conditions. Notably, Ln‐LOF‐101 exhibits an unusual moisture‐enhanced noble‐gas adsorption behavior. Xe‐loaded single‐crystal diffraction of Tb‐LOF‐101, combined with molecular simulations for Rn, identifies four preferential Rn binding sites concentrated around the metal node. Compared with the parent Tb‐MOFs, the high‐entropy MOFs show improved radioluminescence retention under repeated X‐ray irradiation, and their radioluminescence response toward 222 Rn confirms their detection capability. Despite the trade‐off between gas adsorption capability and scintillation efficiency, our work establishes high‐entropy lanthanide‐node engineering as a designable strategy for integrating radioactive‐gas capture, radiation tolerance, and scintillation readout within porous MOF platforms.