RbjMk[Fe(CN)6]l (M = Co, Ni) Prussian Blue Analogue Hollow Nanocubes: a New Example of a Multilevel Pore System

A facile surfactant-free route to synthesize uniform Rb0.4M4[Fe(CN)(6)](2.8)center dot 7.2H(2)O (M = Co, Ni) hollow nanoparticles is described. Rb1.6Mn4[Fe(CN)(6)](3.2)center dot 4.8H(2)O serves as a sacrificial/removable core in the synthesis of core@shell heterostructures. After dissolution of the cores under very mild conditions, the crystalline hollow nanocubes feature well-defined micro-, meso-, and macropores. The surfactant-free approach preserves the reactivity of the Prussian blue analogue surface as evidenced by the subsequent synthesis of hollow shell@shell heterostructures.