High‐Entropy Lanthanide Metal‐Organic Frameworks as Multifunctional Porous Scintillators for Radiation Detection and Dual‐Mode Uranyl Sensing

Despite the burgeoning interest in high-entropy materials (HEMs), their application as scintillators remains largely untapped. Herein, we report the first design of high-entropy lanthanide-based metal-organic frameworks (HE-Ln-MOFs) incorporating five distinct lanthanides (La, Ce, Eu, Dy, and Er) as multifunctional porous scintillators. These materials exhibit stimulus-responsive luminescence, enabling switchable white-light emission and self-calibrating thermometry. The HE-Ln-MOFs demonstrate a balanced optimization of key scintillation parameters, achieving a light yield of ∼17000 photons per MeV and a detection limit as low as 302 nGy_air s^-1. X-ray adsorption spectroscopy (XAS) and theoretical calculations reveal a unique multistep energy transfer (ET) pathway mediated by the Ce³⁺/Ce⁴⁺ redox pair, presumably generated under high-energy X-ray irradiation. Furthermore, HE-Ln-MOFs demonstrate exceptional structural integrity, photostability, and a record uranyl adsorption capacity of 1532 mg g^-1, advantageous over their monometallic analogues. The synergy between ultrahigh adsorption, "turn-on" photoluminescence (PL), and intense scintillating signal output portends unprecedented dual-mode, on-site detection of radionuclides in aqueous environments. This work establishes HE-Ln-MOFs as a promising platform for next-generation porous scintillators in advanced radiation detection technologies.