Uranyl-Tc(VII)/Tc(V) hybrid clusters

Pertechnetate (99TcVIIO4-), reduced Tc, and actinides co-exist in spent nuclear fuel and legacy wastes. They co-transport in fuel reprocessing and waste disposal scenarios, necessitating an understanding of co-speciation. Here, we report five new molecular cluster/framework structures with pentameric and tetrameric uranyl building units decorated by TcO4-/ReO4- oxoanions, or fused with the reduced technetyl cation Tc(V)O. The latter, obtained by Tc auto-reduction (without the intentional introduction of a reducing environment), broadens the basis for Tc-reduction and the burgeoning polyoxometalate-like behavior of technetium.

State-of-the-art progress for the selective crystallization of actinides, synthesis of actinide compounds and their functionalization

Crystallization and immobilization of actinides to form actinide compounds are of significant importance for the extraction and reutilization of nuclear waste in the nuclear industry. In this paper, the state-of-art progress in the crystallization of actinides are summarized, as well as the main functionalization of the actinide compounds, i.e., as adsorbents for heavy metal ions and organic pollutant in waste management, as (photo)catalysts for organic degradation and conversion, including degradation of organic dyes and antibiotics, dehydrogenation of N-heterocycles, CO₂ cycloaddition, selective alcohol oxidation and selective oxidation of sulfides. This review will give a comprehensive summary about the synthesis and application exploration of solid actinide crystalline salts and actinide-based metal organic frameworks in the past decades. Finally, the future perspectives and challenges are proposed in the end to give a promising direction for future investigation.