Ion adsorption and electron transfer in spinel-like iron oxide colloids

Abstract

The behaviour of aqueous spinel-like iron oxide colloids in the presence of metal ions, and especially Fe2+, has been studied protometrically and structurally. Fe2+ adsorption is shown to proceed reversibly with the release of two protons per adsorbed ion; subsequent implication of an Fe3O4 outer shell is demonstrated. All the experimental features support electron transfer involving an octahedral site sub-lattice of the whole colloid.