Synthesis of Prussian Blue Nanoparticles with a Hollow Interior by Controlled Chemical Etching

A facile route has been found to prepare Prussian blue (PB) hollow particles with a cubic shape (see picture). With PB mesocrystals used as a starting material, hollow interiors were created through controlled chemical etching in the presence of poly(vinylpyrrolidone). The hollow cavities and particle sizes could be tuned by changing the synthetic conditions, and the original PB crystallinity was preserved even after formation of interior hollows.