Self-assembly of m-phenylenediamine and polyoxometalate into hollow-sphere and core-in-hollow-shell nanostructures for selective adsorption of dyes

Supramolecular self-assembly is an effective method to assemble organic and inorganic units into various hierarchical structures with excellent properties and is widely used in material and life science. In this article, the self-assembled hollow-sphere and core-in-hollow-shell nanostructures composed of m -phenylenediamine and a novel Preyssler-type polyoxometalates (POM, K 12.5 Na 1.5 [NaP 5 W 30 O 110 ]·15H 2 O (abbreviated as P 5 W 30 )) without template were successfully realized by adjusting the non-covalent interactions. For comparison, we also selected o -phenylenediamine and p -phenylenediamine to investigate whether isomerides have different effects on the self-assembly behavior with P 5 W 30 . The results indicated that only m -phenylenediamine/P 5 W 30 can form hollow spheres and core-in-hollow-shell structure while o -phenylenediamine/P 5 W 30 and p -phenylenediamine/P 5 W 30 cannot which revealed that the self-assembly process can be regulated via isomer effects. Moreover, the detailed analysis of the formation of hollow spheres and core-in-hollow-shell structure are studied and the mechanism is mainly due to the Ostwald ripening . In addition, m -phenylenediamine/P 5 W 30 composite has a good adsorption capacity for methylene blue (MB) dyes, even in the presence of other dyes such as rhodamine B (RB) and amaranth (AR). Our findings further confirmed that supramolecular self-assembly between organic molecules and POM can unique a distinctive “bottom-up” strategy to construct diversiform structures with functional properties.