Non-native transition metal monoxide nanostructures: Unique physicochemical properties and phase transformations of CoO, MnO and ZnO

Abstract

The discovery of unprecedented, non-native phases of transition metal oxides is a fascinating theme in materials chemistry, including the development of new synthetic strategies with excellent size- and phase-selectivity, and elucidation of their unique physicochemical properties. Most of the first-row transition metal monoxides, such as MnO, FeO, CoO and NiO, are known to exist in a cubic phase, but only ZnO adopts a hexagonal structure. This review summarizes recent results on the syntheses and characterization of the non-native phases of h-CoO, h-MnO and c-ZnO transition metal monoxides, compared to their native phases. The investigation of the size- and phase-selective synthetic methods, formation mechanism and unique physicochemical properties of non-native transition metal monoxides would have an enormous impact on materials chemistry and open a promising avenue for magnetic, electronic and spintronic applications.