Pseudomorphic Transformation of Layered Simple Hydroxides into Prussian Blue Analogue Nanoplatelets
Résumé
The reactivity of potassium or sodium hexacyanoferrate(II) with transition-metal layered simple hydroxides (LSHs) has been investigated to evaluate the possibility of inserting Prussian Blue analogues (PBAs) into magnetic copper(II) LSHs. This report shows how such a reaction led, unexpectedly, to the direct formation of PBA nanoparticles, the layered hydroxide serving as a metal-ion reservoir. The lamellar structure of the starting LSH collapses and copper-iron PBA nanoparticles were obtained as well-defined cubic structures stacked in layers. In addition to structural and magnetic characterization, the reaction mechanism was investigated by 57Fe Mössbauer spectrometry and X-ray photoemission spectroscopy. The layered copper hydroxide acetate turns out to be a smart precursor of well-shaped PBA nanoparticle layers through pseudomorphic replication.