Theoretical Design for Thorium-Containing Two-Dimensional Materials.

Actinide elements are characterized by their unique electronic correlations, variable valence states, and localized 5f electrons, leading to unconventional electronic and topological properties in their compounds. The distinctive physical properties of actinide materials are maintained in low-dimensional forms, yet two-dimensional (2D) actinide materials remain largely unexplored due to their scarcity and the experimental challenges posed by their radioactivity. To fill the knowledge gap in 2D actinide materials, we theoretically designed a series of stable thorium-containing 2D materials, including MXenes, chalcogenides, halides, and other compounds with unique structures. These novel thorium-containing 2D materials show excellent thermodynamic, mechanical, and dynamical stability. Their electronic structures and potential applications were investigated. Considering the proper band edge positions, strong visible light absorption, and effective separation of photogenerated electron-hole pairs, ThPSe is proposed as a promising photocatalyst for water splitting. Our work significantly expands the 2D actinide materials family, and further opens new avenues for their experimental realization and applications.