Galvanic Replacement Reactions in Metal Oxide Nanocrystals

TLDR

Corrosion of metal oxide nanoparticles can be harnessed to create hollow metal nanoparticles, where reduction of one metal species in solution drives core dissolution. The authors adapted this approach to Mn₃O₄ nanocrystals by exposing them to Fe²⁺ ions, causing the nanocrystal exterior to be replaced with γ‑Fe₂O₃. At high Fe²⁺ concentrations, hollow γ‑Fe₂O₃ nanocages form, which can serve as anode materials for lithium‑ion batteries. Oh et al.

Abstract

Hollowing Out Metal Oxide Nanoparticles Corrosion is normally a problem, but it can be useful, for example, when you wish to create hollow metal nanoparticles, whereby the reduction of one metal species in solution drives the dissolution of the core of the particle. Oh et al. (p. 964 ; see the Perspective by Ibáñez and Cabot ) adapted this approach to metal oxide nanoparticles by placing Mn 3 O 4 nanocrystals in solution with Fe 2+ ions, which replaces the nanocrystal exterior with γ-Fe 2 O 3 . At sufficiently high Fe 2+ concentrations, hollow γ-Fe 2 O 3 nanocages formed. These hollow structures could be used as anode materials for lithium ion batteries.