Super-alkalis as building blocks of one-dimensional hierarchical electrides

Electrides are ionic compounds where localized electrons act as anions. Because of their exotic properties in optoelectronics and catalysis, electrides have attracted considerable interest in recent years and many electrides, with anionic electrons distributed in zero-, one-, two- and three-dimensions, have been studied. Here, using first-principles calculations, we report a different class of inorganic electrides where Li₃O super-alkali clusters form the building blocks of one-dimensional hierarchical structures, characterized by the presence of localized electrons with high charge density along a one-dimensional chain. We further show that the stability of this electride can be improved by embedding it inside a BN nanotube (BNNT). In addition, Li₃O@BNNT exhibits powerful reducing ability as well as anti-ferromagnetism, highlighting the importance of nano-assembly in the development of new stable electrides with novel properties.