Pioneering radiation dosimetry and photothermal conversion in a photochromic and radiochromic thorium cluster

Understanding the fundamental properties of actinide-based materials is pivotal in unlocking new solutions for challenges in nuclear waste management. In this work, we showcase a novel thorium cluster (Th-npc) that exhibits an extremely rare Th–N bond capping the square antiprismatic Th⁴⁺ metal center. Remarkably, Th-npc exhibits both photochromic and radiochromic behaviors under UV and X-ray radiation, respectively, allowing for distinct, measurable colorimetric shifts that facilitate a red-green-blue (RGB) radiation dosimetry method. The integration of Th-npc with a custom-built optoelectronic device enables on-site radiation dosimetry, offering the advantages of simple operation and rapid data acquisition. Additionally, this work pioneers the application of actinide materials in photothermal conversion, opening new avenues for the strategic utilization of thorium-based compounds.